Marathon: Guy hits Wall in final 200m
March 7, 2010
Filed under Running Videos
Amsterdam Marathon 19-10-08.
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Running Tips & Techniques : How to Exercise with Plyometrics Before Running
November 1, 2009
Filed under Running Videos
Learn how to exercise using plyometric techniques and how this will help you when you are running in thisfree fitness video on running techniques. Expert: Robert Rogers Contact: www.worldhunt.com Bio: Robert Rogers has been a Track and Cross Country Coach for Otto Middle School for the last three years. Filmmaker: Robert Rogers
Sprinting and Jogging Benefits
August 29, 2009
Filed under Running
Performing various cardiovascular exercises has its own advantages and effects. Improved blood pumping rate, reduced cholesterol, fat reduction etc.However various researches point out to the athletic fraternity that a combination of sprinting and jogging would burn the calories and require sufficient endurance from core of the body as well as lower body unlike leisure walks.
The gains to be availed by sprinting is worth the effort There is a substantial amount of peak in the metabolism curve for a longer time horizon than jogging resulting in fat reduction and increase in muscle. it leads to the Hamstring muscle growth. The recovery latency improves the heart and lungs rate. Develops the stamina for long distance runs. Weight loss results are clear enough due to the change in the program leading to a healthy lifestyle.
The whole concept of sprinting boils down to speed and alignment of the upper body relative to foot. Relaxing of arms is mandatory and must be swung while running. Foot must be placed such that it lands completely from heel to toe at one go rather than either of them advancing first to touch the ground and be a cause for injuries.
Range of the stride must be contemplated with huge steps resulting in over stride and the baby steps lead to understride.Relaxation of the mind and body is very much essential while sprinting so as to decrease the chances of fatigue. Repeated cyclical stress of the body must be avoided so as to increase the chances of quick recuperation.
The optimal way to execute this program would be through interval training. In the aforementioned regime it’s necessary for the person to sprint quarter of a distance being earmarked for jogging. Progress is to be made through variation in time duration for each activity as well as intensity. This variation in pattern can be repeated an manipulated so as to suit your needs.
Power of Protein
August 22, 2009
Filed under Diet And Nutrition, Triathlon
Jennifer Hutchison asks how much protein a triathlete really needs.
How much protein does a triathlete need? Is protein in a sports drink really necessary?
These two questions can spark a firestorm of debate amongst sports nutrition professionals, nutrition savvy athletes and sport nutrition manufacturers that promote products packed with a protein punch. This month I will discuss the third macronutrient that provides balance and protection in an athlete’s diet, protein.
Protein Basics
Dietary protein, like carbohydrate and fat, performs a very important job in an athlete’s diet. Protein’s primary role in the body is to support growth, maintenance and repair of muscle and other body tissues, while also being a backbone for many hormones and enzymes and supporting a healthy immune system. An athlete’s overall health and performance can be closely tied to protein balance. Protein intake that is insufficient can place the athlete at risk for illness and or injury.
Body proteins are constantly being broken down and resynthesized on a daily basis both at rest and during training. Protein, although not a preferred fuel source, can be used to sustain physical activity. Gluconeogenesis is the body process that breaks down protein (think muscle) and converts it to carbohydrate (glucose) to be used as fuel.
Dietary protein’s main purpose should be for the repair and recovery of damage muscle and cells caused by training and racing as opposed to being used as a fuel source. In order to do this athletes must ensure that they are already meeting both their daily calorie and carbohydrate needs which have been addressed in previous articles.
Building Blocks
Protein is synthesized from amino acids (the building blocks of protein). There are 20 different amino acids (AA) that, in various combinations, create the different types of protein. What makes a particular protein source unique is how these AAs are combined.
There are two major categories of AAs: Essential and Nonessential.
Essential AAs cannot be made in the body therefore they must be supplied by the diet.
The essential AAs are Histidine, Isoleucine*, Leucine*, Lysine, Methionine, Phenylalanine, Threonine, Tryptphan and Valine*
Food sources that contain all of the essential AAs are commonly referred to as “complete” proteins. These foods include animal proteins such as meat, fish, dairy products and eggs.
Side note: (BCAA) Branch chain amino acids (denoted with the * above) are essential AAs of interest to many endurance athletes as they are thought to play a role in mental “strength” and delaying fatigue. BCAAs are stored in the muscle and can be used as fuel during long training days and for 70.3 to Ironman races,particularly if carbohydrate intake falls short.
In theory, BCAAs supplementation (in the form of protein containing sports drinks) seems to make sense, but there is very little solid research which confirms a performance benefit. Consuming sports drinks with protein is not harmful. The biggest subjective issue I have encountered with Ironman athletes is taste. Sports drinks containing protein do not taste so swell after a few hours roasting in the heat. If an athlete is not keen on the taste of their sports drink, they most likely will not drink enough, which can be problematic on race day!
So the burning question: is a protein containing sports drink really needed during endurance training? The answer is no. With that said, I do know of many athletes who swear by their carb/protein potion. So as they say “if it ain’t broke, don’t fuss with it”.
Nonessential amino acids are just as important as essential AAs with the difference being these AAs CAN be made by the body and do not have to come from the diet. Nonessential AAs s are Alanine, Arginine, Asparagine, Aspartic acid, Cysteine, Glutamine, Glutamic Acid, Glycine, Proline, Serine and Tyrosine.
Food sources that may be lacking in one or more of the essential AAs is referred to as “incomplete” proteins. All plant sources of protein (beans, legumes, whole grains, vegetables, nuts and seeds) with the exception of soy are considered incomplete.
Athletes that choose to follow a plant based (vegetarian) training diet should include soy products and incorporate variety in selecting beans/ legumes, whole grains and vegetables. Protein needs CAN be met following a vegetarian diet but these athletes have to ensure they compliment their grain choices with their meat alternative choices so that all the AAs are being supplied over the course of the day.
Protein Requirements
In spite of popular belief, endurance athletes can meet their protein needs without tons of dietary supplements.
The keys to meeting protein needs are 1) knowing how much protein to aim for 2) learning more about the protein content of various foods and 3) planning meals … which can be easier said than done!
Athlete protein needs are based on lean body weight (preferred over total body weight), the type of training (strength/power vs. endurance) and phase of training (base/ build/peak/race). Athletes new to physical training, in general will have a slightly higher protein need than those athletes who have more training experience.
The average athlete may only need the recommended 0.8 gm protein per kilogram body weight per day.
However the very nature of preparing for the 70.3 and Ironman distances will most certainly require a bit more to mend a body battered from 12 to 20+ weekly training hours.
The chart below can be used as a guide to estimate daily protein needs based on the daily training volume. It would be fair to say that athletes who have shorter, more intense, workouts which produce some degree of muscle damage (i.e. muscle soreness) may benefit from that next higher level of protein intake.
|
Daily Training |
Grams per pound body weight |
Grams per kilogram (kg) body weight |
|
Up to 60 min per day |
0.5 |
1.1 |
|
Between 1 to 2 hours |
0.6 |
1.3 |
|
Between 2 to 3 hours |
0.7 |
1.5 |
|
Greater than 3 hours |
0.8 |
1.8 |
More is not better
Most athletes with a well balanced diet can easily meet their daily protein requirements. It is a common practice for some athletes to over consume protein believing this in turn will help boost lean body mass. The truth is that the body does not store excess dietary protein as muscle. Once dietary protein has fulfilled its role the excess is broken down and goes to be used as fuel, stored as body fat or excreted by the body via urine.
Protein content of various foods
Oils – none
Fruit- minimal
Grains- 3 grams per serving (1 sl bread, ½ c rice or pasta)
Nuts – 5 grams per 1 oz
Milk/Dairy/ Milk Alternative- 5 to 8 grams per serving (8 oz milk, 6 oz yogurt, 1 oz cheese) Cottage Cheese- 14 grams per ½ cup
Beans – 7 to 8 grams per ½ cup
Meat Alternative/ Soy – 16 to 20 grams per ½ c ( tofu, tempeh) 1 Egg – 7 to 9 grams
Meat – 21 to 27 grams per 3 oz cooked (beef, chicken, turkey, fish, pork)
How much is a portion? For most normal size athletes, the inside diameter of your hand and thickness of your palm is your rough guide to a meat portion appropriate for you.
Nutrition tips for meeting daily protein needs:
Include a protein containing food at every meal and every post workout snack.
To optimize the recovery process, target 10-20 grams of protein (along with the carbohydrate source) in post workout snacks.
Breakfast Ideas
· High protein cereal (ex: Kashi Go Lean), low fat dairy/soy (milk, yogurt)
· Scrambled egg white omelet w/ low fat cheese
· Add 1 scoop soy/ whey protein isolate powder to your hot cereal
· Use milk or soymilk instead of water for hot cereal.
Lunch Ideas
· Turkey/ Tuna/ Chicken Wrap, Beans & Rice, Bean Burrito
· Add part skim mozzarella cheese, crumbled tofu or chickpeas to salads
· Eating out? Request double meat on your sandwiches.
Dinner Ideas
· Tofu Stir Fry w/ Brown Rice, All Bean Chili w/ Rice
· Grilled Chicken, Lean Beef, Pork, Baked Fish with Potatoes or Pasta
· Quinoa and Black Beans served with shredded lowfat soy cheese
Snack Ideas
· Low fat Cheese, Cottage Cheese, Low fat Yogurt with fruit
· Chocolate Milk, Smoothie made w/ Soymilk
· Whole Grain Toast/ Muffin with Peanut or Almond butter
Adequate daily protein is crucial for athletes to maintain a strong, healthy and powerful body. Knowing what your daily needs are is one thing, but knowing you are consuming adequate protein on a daily basis is another. Make use of the many good online resources and lists that can be found that identify the quantity of protein contained in various foods and track your daily intake of not only protein but also carbohydrate and fat as previously discussed in the past couple Ironman.com nutrition articles. If all the numbers and calculations leave you with a headache then consider adding a sports dietitian to your personal performance enhancement team. The use of a qualified sports nutrition professional, like that of a skilled endurance coach can help you take the guess work out of your daily and weekly eating plan and allow you to focus on what most Ironman and 70.3 athletes enjoy the most……..train, eat, sleep and race.
Jennifer Hutchison, RD, CSSD is Board Certified as a Specialist in Sports Dietetics, a USA Triathlon Certified Level 3 Elite Coach. As a Registered Dietitian, Jennifer uses her academic training, certifications and “real world” experience to help fuel athletes worldwide. You can direct comments, questions or suggestions for further articles to Jennifer via email to eSportsRD@aol.com or go to www.IronCladCoaching.com . References available upon request.
Getting Specific About Your Running Goals
August 13, 2009
Filed under Running
…from The Everything Running Book, 2nd Edition.
- Be specific about your running goals & needs
- Identify short- & long-term running goals
- Follow a training plan from a qualified coach
In order to come up with a program that will work best for you, you need to be specific about your needs and goals. Obtain a new notebook and label it simply “Running.”
On the first page, think about what you want to accomplish. Consider, for example:
- Is your primary goal to lose a certain amount of weight? How much do you want to lose? Be realistic about how long it should take. You’ll have a sense of how well the running compliments the other work you do to reach your weight-loss goal once you are doing it regularly. Don’t assume, however, that a slow mile-long jog every few days is going to drop you from a size 10 to a size 6 in a couple of months. Jogging will certainly help to lose inches, but it’ll take time.
- Is your goal to advance from an occasional run through the neighborhood park to competing in an organized race? Do you want to start with a 5K, or have you suddenly decided you want to run a marathon next year?
- Have you chosen running as an economical alternative to a health club membership? Hey, why not? You’re certainly out less money in the long run if in a few months you realize you have neither the time nor inclination for regular exercise. All the same, you won’t regret choosing running, both for the cost savings and for the way you’re going to feel once you get into it.
- Do you need to fit running into a very busy schedule? If so, you may only have time for a half-hour run a day. That’s fine! This book will help you to optimize the time you do have.
Whatever your short- or long-term goals are for choosing to run, identify them in your notebook so you can be reminded of them. This will keep you focused when the inevitable temptation to do other things comes up.
Don’t be vague, and decide which is your number one goal, and stick with the program that will get you there. Haphazardly jumping from one training plan to another will only frustrate you and take you further away from achieving something significant.
If possible, find a coach and follow her training plan. A qualified coach will consult with you on a regular basis so that your program can be modified should you experience fatigue, soreness, or injury.
10 for the Road: Essential Nutrients for Endurance Athletes
August 12, 2009
Filed under Crossfit, Diet And Nutrition, Running, Triathlon
By Alan Christianson, N.D
Quite simply, athletes need more nutrients than less-active people. They demand more from their bodies than even average fitness buffs and so must compensate with the right nutrients from foods or supplements to keep performance—and recovery—at its peak.
The more intense the exercise or sport, the greater the body's nutrient needs. Athletes who participate in endurance sports—those that involve more than one hour of consistent activity—have specific needs because of what they demand from their bodies. For example, athletes lose more electrolytes, such as magnesium, potassium and sodium, through perspiration and must diligently replace them. The wear and tear of intense activity may necessitate increased intake of antioxidants such as vitamin E, which can help protect muscle cells from oxidative damage. Since muscle-tissue breakdown is common during intense exercise, athletes also need more proteins to repair the tissues.
To keep their bodies performing optimally, endurance athletes should be familiar with these 10 important nutrients.
The first seven essential supplements are the minerals calcium, iron, magnesium, potassium, selenium, sodium and zinc. Their benefits range from keeping bones strong to minimizing fatigue.
- CALCIUM This may be the most important nutrient for an athlete. In a survey of more than 10,000 male and female athletes ages 7 to 50, fewer than half consumed 1,000 mg of calcium daily.1 The recommended dietary intake ranges from 1,000 to 1,500 mg/day depending on age and gender.
For female athletes, calcium intake is of particular concern. Excessive training—more than seven hours per week—may cause hormonal declines in young girls that can stop menstruation. This hormonal decline also compromises bone formation, possibly leading to premature, irreversible osteoporosis.2 Recent research shows that male endurance athletes of all ages experience testosterone deficits that also can cause osteoporosis.3
Athletes should monitor their calcium intake. Dairy foods can supply the required amounts unless sensitivities exclude them from the diet. But a diet without dairy foods requires supplements. All athletes should make sure they get 1,200 to 1,500 mg of calcium daily from food or supplements. Drinking a cup of skim milk, for example, provides about 300 mg of calcium.
- IRON For the casual athlete who trains less than four hours per week, iron deficiency is no more of a concern than for a sedentary person. But athletes who train for six or more hours per week often have iron-deficiency anemia and should be checked yearly for the condition. Female athletes who are unable to correct such mild anemia through diet can benefit from supplements.4
(26.2 miles)
Triathlons
(swim, bike, run)
Ultramarathons
(50 or 100 miles) Athletes use iron stores more quickly than nonathletes and, considering the neurologic effects of anemia on children and teens who engage in rigorous sports, adequate intake of iron is quite important.5 The recommended dietary allowance (RDA) for iron ranges from 10 to 15 mg/day—an amount easily acquired from food. In the absence of anemia, athletes shouldn't take any supplemental iron because it raises the risk of heart disease and colon cancer.
|
Athletes lose magnesium through sweat and urine. This, combined with the fact that athletes' diets are usually low in magnesium, generally leads to the need for supplementation.7 Recommended intake for endurance athletes is 500 to 800 mg daily.8 Higher doses can cause diarrhea.
In a study of athletes running 40 minutes at 70 degrees Fahrenheit, potassium loss was estimated at 435 mg/hour. The rate of potassium loss is approximately 200 mg/kg of weight lost during exercise.9 Cells release potassium into the bloodstream and serum levels rise with exercise, possibly instigating fatigue. Potassium supplementation after short events (less than two hours), and during and after long events, is warranted.10 For postactivity replacement, athletes should take about 435 mg/hour of exercise or 200 mg/kg of weight loss. As much as 150 mg/hour during activity can be tolerated by most athletes. Supplement potassium cautiously because too much too quickly can cause cardiac arrest. Supplementing with potassium during training does increase markers of recovery, primarily serum lactate and muscle hydration, but does not aid performance.10
Research shows selenium benefits athletes' immune function and helps repair cellular damage. Researchers studied the selenium supplementation effects on muscle SeGPx in 24 healthy nonsmoking males. Half took 240 mcg of sodium selenite; half took placebo. After cycling to exhaustion—durations ranged from 2.6 to 3.5 hours—the group that took selenium showed less cellular damage.12 Supplementation with 200 mcg of selenium is safe and warranted for endurance athletes.13
A prospective study was performed on 36 athletes during a three- to four-hour triathlon and 64 athletes at an ironman race, which lasts between nine and 15 hours. No athletes were hyponatremic after the shorter race, but 27 percent were hyponatremic following the ironman. An average of 17 percent of the ironman participants required medical attention, most for hyponatremia.14 Extrapolated from that study, athletes should aim for 80 to 100 mg sodium per quart of hydrating beverage and 100 to 300 mg sodium per hour from other sources.
Those who train without days off lose zinc even more quickly. In a study of cyclists, researchers looked at zinc excretion via sweat. Half of the group underwent intense training for two months. Half underwent moderate training with two to three days off per week. Both groups were studied before and after. The exercising group showed increased zinc excretion while the control group showed no increase.16 The researchers believe altered zinc metabolism coupled with increased zinc excretion and stress levels lead to fatigue and decreased endurance. Athletes should take 30 to 60 mg zinc daily.17 Zinc picolinate or monomethionate are most easily tolerated.18 Prevent Oxidative Damage
In a study of 30 top-class cyclists, five months of supplementation with natural vitamin E (alpha-tocopherol) at an 800-IU daily dose significantly decreased markers of oxidative damage to muscle tissue. However, vitamin E did not benefit athletic performance. Studies evaluating vitamin E as an ergogenic, or performance aid, show no benefit.19 One possible exception is at higher altitudes where oxidative stress is more intense. A group of six mountain climbers took 400 mg synthetic vitamin E (dl-alpha-tocopherol acetate). During exertion at altitude, they showed less output of pentane and lactic acid—both markers of oxidative damage, but not suggestive of improved athletic performance. The athletes also showed a statistically significant increase in anaerobic threshold compared to a placebo group.20 The amount of vitamin E necessary to benefit athletes is not obtainable through diet. The jury is still out on natural vs. synthetic vitamin E, but endurance athletes should take 400 to 800 IU/day. Protein and Glutamine
Endurance athletes need more protein for different reasons than strength athletes do. Endurance athletes primarily use protein for maintaining aerobic metabolism, compared with the increased tissue-repair needs of strength athletes. When intake is inadequate, the body sequesters the needed proteins from lean tissue, which gives overtrained endurance athletes a gaunt appearance. A protein deficit also impairs an athlete's recovery and wound-healing ability.14 Researchers recommend endurance athletes eat 1.2 to 1.4 g/kg of body weight/day of protein.22 For a 155-pound athlete, this means a total of 85 to 100 g protein per day. Only a few studies recommend protein intake levels as high as 2 g/kg of body weight/day.23
Oral glutamine replacement after exercise can lower infection risk. In one study, 200 runners and rowers were given placebo or 2,000 mg glutamine two hours after exercise. In the seven days following the exercise, 81 percent of the glutamine-supplemented group were infection-free compared to 49 percent in the placebo group.26 A supplement that provides 2 g glutamine daily is a wise choice for athletes in training.26 Athletes who train strenuously for competition have greater nutritional needs than sedentary people. Adequate nutrients can mean quicker recovery time, lower infection rates, less fatigue, and ultimately, can help athletes reach their desired performance levels.
References 1. Guezennec CY, et al. Is there a relationship between physical activity and dietary calcium intake? A survey in 10,373 young French subjects. Med Sci Sports Exerc 1998 May;30(5):732-9. 2. Voss LA, et al. Exercise-induced loss of bone density in athletes. J Am Acad Orthop Surg 1998 Nov-Dec;6(6):349-57. 3. Bennell KL, et al. Effect of altered reproductive function and lowered testosterone levels on bone density in male endurance athletes. Br J Sports Med 1996 Sep;30(3):205-8. 4. Eichner ER. Sports anemia, iron supplements, and blood doping. Med Sci Sports Exerc 1992 Sep;24(9 Suppl):S315-8. 5. Weaver CM, et al. Exercise and iron status. J Nutr 1992 Mar;122(3 Suppl):782-7. 6. Altura BM, et al. Magnesium depletion impairs myocardial carbohydrate and lipid metabolism and cardiac bioenergetics and raises myocardial calcium content in-vivo: relationship to etiology of cardiac diseases. Biochem Mol Biol Int 1996 Dec;40(6):1183-90. 7. Lukaski HC, et al. Micronutrients (magnesium, zinc, and copper): are mineral supplements needed for athletes? Int J Sport Nutr, 1995;5 Suppl:S74-83. 8. Seelig M. Magnesium deficiency in the pathogenesis of disease. New York: Plenum Press; 1980. 9. Wenk C, et al. Methodological studies of the estimation of loss of sodium, potassium, calcium and magnesium through the skin during a 10 km run. Z Ernahrungswiss 1993 Dec;(4):301-7. 10. Tarnopolsky MA, et al. Mixed carbohydrate supplementation increases carbohydrate oxidation and endurance exercise performance and attenuates potassium accumulation. Int J Sport Nutr 1996 Dec;(4):323-36. 11. Venditti P. Effect of training on antioxidant capacity, tissue damage, and endurance of adult male rats. Int J Sports Med 1997 Oct;18(7):497-502. 12. Tessier F, et al. Muscle GSH-Px activity after prolonged exercise, training, and selenium supplementation. Biol Trace Elem Res, 1995 Jan-Mar;47(1-3):279-85. 13. Persson-Moschos M, et al. Plasma selenoprotein P levels of healthy males in different selenium status after oral supplementation with different forms of selenium. Eur J Clin Nutr 1998 May;52(5):363-7. 14. Hiller WD, et al. Medical and physiological considerations in triathlons. Am J Sports Med 1987 Mar;(2):164-7. 15. Cordova A. Behaviour of zinc in physical exercise: a special reference to immunity and fatigue. Neurosci Biobehav Rev 1995 Fall;19(3):439-45. 16. Cordova A, et al. Effect of training on zinc metabolism: changes in serum and sweat zinc concentrations in sportsmen. Ann Nutr Metab 1998;42(5):274-82. 17. Barrie SA, et al. Comparative absorption of zinc picolinate, zinc citrate and zinc gluconate in humans. Agents Actions 1987;21(1-2):223-8. 18. Rohde T, et al. Effect of glutamine supplementation on changes in the immune system induced by repeated exercise. Med Sci Sports Exerc 1998 Jun;30(6):856-62. 19. Rokitzki L, et al. Alpha-tocopherol supplementation in racing cyclists during extreme endurance training. Int J Sport Nutr 1994 Sep;4(3):253-64. 20. Simon-Schnass I, et al. Influence of vitamin E on physical performance. Int J Vitam Nutr Res 1988;58(1):49-54. 21. Lemon PW, et al. Do athletes need more dietary protein and amino acids? Int J Sport Nutr 1995 Jun;5 Suppl:S39-61. 22. Shephard, RJ, et al. Immunological hazards from nutritional imbalance in athletes. Exerc Immunol Rev 1998;4:22-48. 23. Rohde T, et al. The immune system and serum glutamine during a triathlon. Eur J Appl Physiol 1996;74(5):428-34. 24. Newsholme EA, et al. The proposed role of glutamine in some cells of the immune system and speculative consequences for the whole animal. Nutrition 1997 Jul-Aug; 13(7-8):728-30. 25.Rohde T, et al. Effect of glutamine supplementation on changes in the immune system induced by repeated exercise. Med Sci Sports Exerc 1998 Jun;30(6):856-62. 26.Castell LM, et al. Does glutamine have a role in reducing infections in athletes? Eur J Appl Physiol 1996;73(5):488-90.
|
Athletes lose magnesium through sweat and urine. This, combined with the fact that athletes' diets are usually low in magnesium, generally leads to the need for supplementation.7 Recommended intake for endurance athletes is 500 to 800 mg daily.8 Higher doses can cause diarrhea.
In a study of athletes running 40 minutes at 70 degrees Fahrenheit, potassium loss was estimated at 435 mg/hour. The rate of potassium loss is approximately 200 mg/kg of weight lost during exercise.9 Cells release potassium into the bloodstream and serum levels rise with exercise, possibly instigating fatigue. Potassium supplementation after short events (less than two hours), and during and after long events, is warranted.10 For postactivity replacement, athletes should take about 435 mg/hour of exercise or 200 mg/kg of weight loss. As much as 150 mg/hour during activity can be tolerated by most athletes. Supplement potassium cautiously because too much too quickly can cause cardiac arrest. Supplementing with potassium during training does increase markers of recovery, primarily serum lactate and muscle hydration, but does not aid performance.10
Research shows selenium benefits athletes' immune function and helps repair cellular damage. Researchers studied the selenium supplementation effects on muscle SeGPx in 24 healthy nonsmoking males. Half took 240 mcg of sodium selenite; half took placebo. After cycling to exhaustion—durations ranged from 2.6 to 3.5 hours—the group that took selenium showed less cellular damage.12 Supplementation with 200 mcg of selenium is safe and warranted for endurance athletes.13
A prospective study was performed on 36 athletes during a three- to four-hour triathlon and 64 athletes at an ironman race, which lasts between nine and 15 hours. No athletes were hyponatremic after the shorter race, but 27 percent were hyponatremic following the ironman. An average of 17 percent of the ironman participants required medical attention, most for hyponatremia.14 Extrapolated from that study, athletes should aim for 80 to 100 mg sodium per quart of hydrating beverage and 100 to 300 mg sodium per hour from other sources.
Those who train without days off lose zinc even more quickly. In a study of cyclists, researchers looked at zinc excretion via sweat. Half of the group underwent intense training for two months. Half underwent moderate training with two to three days off per week. Both groups were studied before and after. The exercising group showed increased zinc excretion while the control group showed no increase.16 The researchers believe altered zinc metabolism coupled with increased zinc excretion and stress levels lead to fatigue and decreased endurance. Athletes should take 30 to 60 mg zinc daily.17 Zinc picolinate or monomethionate are most easily tolerated.18 Prevent Oxidative Damage
In a study of 30 top-class cyclists, five months of supplementation with natural vitamin E (alpha-tocopherol) at an 800-IU daily dose significantly decreased markers of oxidative damage to muscle tissue. However, vitamin E did not benefit athletic performance. Studies evaluating vitamin E as an ergogenic, or performance aid, show no benefit.19 One possible exception is at higher altitudes where oxidative stress is more intense. A group of six mountain climbers took 400 mg synthetic vitamin E (dl-alpha-tocopherol acetate). During exertion at altitude, they showed less output of pentane and lactic acid—both markers of oxidative damage, but not suggestive of improved athletic performance. The athletes also showed a statistically significant increase in anaerobic threshold compared to a placebo group.20 The amount of vitamin E necessary to benefit athletes is not obtainable through diet. The jury is still out on natural vs. synthetic vitamin E, but endurance athletes should take 400 to 800 IU/day. Protein and Glutamine
Endurance athletes need more protein for different reasons than strength athletes do. Endurance athletes primarily use protein for maintaining aerobic metabolism, compared with the increased tissue-repair needs of strength athletes. When intake is inadequate, the body sequesters the needed proteins from lean tissue, which gives overtrained endurance athletes a gaunt appearance. A protein deficit also impairs an athlete's recovery and wound-healing ability.14 Researchers recommend endurance athletes eat 1.2 to 1.4 g/kg of body weight/day of protein.22 For a 155-pound athlete, this means a total of 85 to 100 g protein per day. Only a few studies recommend protein intake levels as high as 2 g/kg of body weight/day.23
Oral glutamine replacement after exercise can lower infection risk. In one study, 200 runners and rowers were given placebo or 2,000 mg glutamine two hours after exercise. In the seven days following the exercise, 81 percent of the glutamine-supplemented group were infection-free compared to 49 percent in the placebo group.26 A supplement that provides 2 g glutamine daily is a wise choice for athletes in training.26 Athletes who train strenuously for competition have greater nutritional needs than sedentary people. Adequate nutrients can mean quicker recovery time, lower infection rates, less fatigue, and ultimately, can help athletes reach their desired performance levels.
References 1. Guezennec CY, et al. Is there a relationship between physical activity and dietary calcium intake? A survey in 10,373 young French subjects. Med Sci Sports Exerc 1998 May;30(5):732-9. 2. Voss LA, et al. Exercise-induced loss of bone density in athletes. J Am Acad Orthop Surg 1998 Nov-Dec;6(6):349-57. 3. Bennell KL, et al. Effect of altered reproductive function and lowered testosterone levels on bone density in male endurance athletes. Br J Sports Med 1996 Sep;30(3):205-8. 4. Eichner ER. Sports anemia, iron supplements, and blood doping. Med Sci Sports Exerc 1992 Sep;24(9 Suppl):S315-8. 5. Weaver CM, et al. Exercise and iron status. J Nutr 1992 Mar;122(3 Suppl):782-7. 6. Altura BM, et al. Magnesium depletion impairs myocardial carbohydrate and lipid metabolism and cardiac bioenergetics and raises myocardial calcium content in-vivo: relationship to etiology of cardiac diseases. Biochem Mol Biol Int 1996 Dec;40(6):1183-90. 7. Lukaski HC, et al. Micronutrients (magnesium, zinc, and copper): are mineral supplements needed for athletes? Int J Sport Nutr, 1995;5 Suppl:S74-83. 8. Seelig M. Magnesium deficiency in the pathogenesis of disease. New York: Plenum Press; 1980. 9. Wenk C, et al. Methodological studies of the estimation of loss of sodium, potassium, calcium and magnesium through the skin during a 10 km run. Z Ernahrungswiss 1993 Dec;(4):301-7. 10. Tarnopolsky MA, et al. Mixed carbohydrate supplementation increases carbohydrate oxidation and endurance exercise performance and attenuates potassium accumulation. Int J Sport Nutr 1996 Dec;(4):323-36. 11. Venditti P. Effect of training on antioxidant capacity, tissue damage, and endurance of adult male rats. Int J Sports Med 1997 Oct;18(7):497-502. 12. Tessier F, et al. Muscle GSH-Px activity after prolonged exercise, training, and selenium supplementation. Biol Trace Elem Res, 1995 Jan-Mar;47(1-3):279-85. 13. Persson-Moschos M, et al. Plasma selenoprotein P levels of healthy males in different selenium status after oral supplementation with different forms of selenium. Eur J Clin Nutr 1998 May;52(5):363-7. 14. Hiller WD, et al. Medical and physiological considerations in triathlons. Am J Sports Med 1987 Mar;(2):164-7. 15. Cordova A. Behaviour of zinc in physical exercise: a special reference to immunity and fatigue. Neurosci Biobehav Rev 1995 Fall;19(3):439-45. 16. Cordova A, et al. Effect of training on zinc metabolism: changes in serum and sweat zinc concentrations in sportsmen. Ann Nutr Metab 1998;42(5):274-82. 17. Barrie SA, et al. Comparative absorption of zinc picolinate, zinc citrate and zinc gluconate in humans. Agents Actions 1987;21(1-2):223-8. 18. Rohde T, et al. Effect of glutamine supplementation on changes in the immune system induced by repeated exercise. Med Sci Sports Exerc 1998 Jun;30(6):856-62. 19. Rokitzki L, et al. Alpha-tocopherol supplementation in racing cyclists during extreme endurance training. Int J Sport Nutr 1994 Sep;4(3):253-64. 20. Simon-Schnass I, et al. Influence of vitamin E on physical performance. Int J Vitam Nutr Res 1988;58(1):49-54. 21. Lemon PW, et al. Do athletes need more dietary protein and amino acids? Int J Sport Nutr 1995 Jun;5 Suppl:S39-61. 22. Shephard, RJ, et al. Immunological hazards from nutritional imbalance in athletes. Exerc Immunol Rev 1998;4:22-48. 23. Rohde T, et al. The immune system and serum glutamine during a triathlon. Eur J Appl Physiol 1996;74(5):428-34. 24. Newsholme EA, et al. The proposed role of glutamine in some cells of the immune system and speculative consequences for the whole animal. Nutrition 1997 Jul-Aug; 13(7-8):728-30. 25.Rohde T, et al. Effect of glutamine supplementation on changes in the immune system induced by repeated exercise. Med Sci Sports Exerc 1998 Jun;30(6):856-62. 26.Castell LM, et al. Does glutamine have a role in reducing infections in athletes? Eur J Appl Physiol 1996;73(5):488-90.
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Athletes lose magnesium through sweat and urine. This, combined with the fact that athletes' diets are usually low in magnesium, generally leads to the need for supplementation.7 Recommended intake for endurance athletes is 500 to 800 mg daily.8 Higher doses can cause diarrhea.
In a study of athletes running 40 minutes at 70 degrees Fahrenheit, potassium loss was estimated at 435 mg/hour. The rate of potassium loss is approximately 200 mg/kg of weight lost during exercise.9 Cells release potassium into the bloodstream and serum levels rise with exercise, possibly instigating fatigue. Potassium supplementation after short events (less than two hours), and during and after long events, is warranted.10 For postactivity replacement, athletes should take about 435 mg/hour of exercise or 200 mg/kg of weight loss. As much as 150 mg/hour during activity can be tolerated by most athletes. Supplement potassium cautiously because too much too quickly can cause cardiac arrest. Supplementing with potassium during training does increase markers of recovery, primarily serum lactate and muscle hydration, but does not aid performance.10
Research shows selenium benefits athletes' immune function and helps repair cellular damage. Researchers studied the selenium supplementation effects on muscle SeGPx in 24 healthy nonsmoking males. Half took 240 mcg of sodium selenite; half took placebo. After cycling to exhaustion—durations ranged from 2.6 to 3.5 hours—the group that took selenium showed less cellular damage.12 Supplementation with 200 mcg of selenium is safe and warranted for endurance athletes.13
A prospective study was performed on 36 athletes during a three- to four-hour triathlon and 64 athletes at an ironman race, which lasts between nine and 15 hours. No athletes were hyponatremic after the shorter race, but 27 percent were hyponatremic following the ironman. An average of 17 percent of the ironman participants required medical attention, most for hyponatremia.14 Extrapolated from that study, athletes should aim for 80 to 100 mg sodium per quart of hydrating beverage and 100 to 300 mg sodium per hour from other sources.
Those who train without days off lose zinc even more quickly. In a study of cyclists, researchers looked at zinc excretion via sweat. Half of the group underwent intense training for two months. Half underwent moderate training with two to three days off per week. Both groups were studied before and after. The exercising group showed increased zinc excretion while the control group showed no increase.16 The researchers believe altered zinc metabolism coupled with increased zinc excretion and stress levels lead to fatigue and decreased endurance. Athletes should take 30 to 60 mg zinc daily.17 Zinc picolinate or monomethionate are most easily tolerated.18 Prevent Oxidative Damage
In a study of 30 top-class cyclists, five months of supplementation with natural vitamin E (alpha-tocopherol) at an 800-IU daily dose significantly decreased markers of oxidative damage to muscle tissue. However, vitamin E did not benefit athletic performance. Studies evaluating vitamin E as an ergogenic, or performance aid, show no benefit.19 One possible exception is at higher altitudes where oxidative stress is more intense. A group of six mountain climbers took 400 mg synthetic vitamin E (dl-alpha-tocopherol acetate). During exertion at altitude, they showed less output of pentane and lactic acid—both markers of oxidative damage, but not suggestive of improved athletic performance. The athletes also showed a statistically significant increase in anaerobic threshold compared to a placebo group.20 The amount of vitamin E necessary to benefit athletes is not obtainable through diet. The jury is still out on natural vs. synthetic vitamin E, but endurance athletes should take 400 to 800 IU/day. Protein and Glutamine
Endurance athletes need more protein for different reasons than strength athletes do. Endurance athletes primarily use protein for maintaining aerobic metabolism, compared with the increased tissue-repair needs of strength athletes. When intake is inadequate, the body sequesters the needed proteins from lean tissue, which gives overtrained endurance athletes a gaunt appearance. A protein deficit also impairs an athlete's recovery and wound-healing ability.14 Researchers recommend endurance athletes eat 1.2 to 1.4 g/kg of body weight/day of protein.22 For a 155-pound athlete, this means a total of 85 to 100 g protein per day. Only a few studies recommend protein intake levels as high as 2 g/kg of body weight/day.23
Oral glutamine replacement after exercise can lower infection risk. In one study, 200 runners and rowers were given placebo or 2,000 mg glutamine two hours after exercise. In the seven days following the exercise, 81 percent of the glutamine-supplemented group were infection-free compared to 49 percent in the placebo group.26 A supplement that provides 2 g glutamine daily is a wise choice for athletes in training.26 Athletes who train strenuously for competition have greater nutritional needs than sedentary people. Adequate nutrients can mean quicker recovery time, lower infection rates, less fatigue, and ultimately, can help athletes reach their desired performance levels.
References 1. Guezennec CY, et al. Is there a relationship between physical activity and dietary calcium intake? A survey in 10,373 young French subjects. Med Sci Sports Exerc 1998 May;30(5):732-9. 2. Voss LA, et al. Exercise-induced loss of bone density in athletes. J Am Acad Orthop Surg 1998 Nov-Dec;6(6):349-57. 3. Bennell KL, et al. Effect of altered reproductive function and lowered testosterone levels on bone density in male endurance athletes. Br J Sports Med 1996 Sep;30(3):205-8. 4. Eichner ER. Sports anemia, iron supplements, and blood doping. Med Sci Sports Exerc 1992 Sep;24(9 Suppl):S315-8. 5. Weaver CM, et al. Exercise and iron status. J Nutr 1992 Mar;122(3 Suppl):782-7. 6. Altura BM, et al. Magnesium depletion impairs myocardial carbohydrate and lipid metabolism and cardiac bioenergetics and raises myocardial calcium content in-vivo: relationship to etiology of cardiac diseases. Biochem Mol Biol Int 1996 Dec;40(6):1183-90. 7. Lukaski HC, et al. Micronutrients (magnesium, zinc, and copper): are mineral supplements needed for athletes? Int J Sport Nutr, 1995;5 Suppl:S74-83. 8. Seelig M. Magnesium deficiency in the pathogenesis of disease. New York: Plenum Press; 1980. 9. Wenk C, et al. Methodological studies of the estimation of loss of sodium, potassium, calcium and magnesium through the skin during a 10 km run. Z Ernahrungswiss 1993 Dec;(4):301-7. 10. Tarnopolsky MA, et al. Mixed carbohydrate supplementation increases carbohydrate oxidation and endurance exercise performance and attenuates potassium accumulation. Int J Sport Nutr 1996 Dec;(4):323-36. 11. Venditti P. Effect of training on antioxidant capacity, tissue damage, and endurance of adult male rats. Int J Sports Med 1997 Oct;18(7):497-502. 12. Tessier F, et al. Muscle GSH-Px activity after prolonged exercise, training, and selenium supplementation. Biol Trace Elem Res, 1995 Jan-Mar;47(1-3):279-85. 13. Persson-Moschos M, et al. Plasma selenoprotein P levels of healthy males in different selenium status after oral supplementation with different forms of selenium. Eur J Clin Nutr 1998 May;52(5):363-7. 14. Hiller WD, et al. Medical and physiological considerations in triathlons. Am J Sports Med 1987 Mar;(2):164-7. 15. Cordova A. Behaviour of zinc in physical exercise: a special reference to immunity and fatigue. Neurosci Biobehav Rev 1995 Fall;19(3):439-45. 16. Cordova A, et al. Effect of training on zinc metabolism: changes in serum and sweat zinc concentrations in sportsmen. Ann Nutr Metab 1998;42(5):274-82. 17. Barrie SA, et al. Comparative absorption of zinc picolinate, zinc citrate and zinc gluconate in humans. Agents Actions 1987;21(1-2):223-8. 18. Rohde T, et al. Effect of glutamine supplementation on changes in the immune system induced by repeated exercise. Med Sci Sports Exerc 1998 Jun;30(6):856-62. 19. Rokitzki L, et al. Alpha-tocopherol supplementation in racing cyclists during extreme endurance training. Int J Sport Nutr 1994 Sep;4(3):253-64. 20. Simon-Schnass I, et al. Influence of vitamin E on physical performance. Int J Vitam Nutr Res 1988;58(1):49-54. 21. Lemon PW, et al. Do athletes need more dietary protein and amino acids? Int J Sport Nutr 1995 Jun;5 Suppl:S39-61. 22. Shephard, RJ, et al. Immunological hazards from nutritional imbalance in athletes. Exerc Immunol Rev 1998;4:22-48. 23. Rohde T, et al. The immune system and serum glutamine during a triathlon. Eur J Appl Physiol 1996;74(5):428-34. 24. Newsholme EA, et al. The proposed role of glutamine in some cells of the immune system and speculative consequences for the whole animal. Nutrition 1997 Jul-Aug; 13(7-8):728-30. 25.Rohde T, et al. Effect of glutamine supplementation on changes in the immune system induced by repeated exercise. Med Sci Sports Exerc 1998 Jun;30(6):856-62. 26.Castell LM, et al. Does glutamine have a role in reducing infections in athletes? Eur J Appl Physiol 1996;73(5):488-90.
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Athletes lose magnesium through sweat and urine. This, combined with the fact that athletes' diets are usually low in magnesium, generally leads to the need for supplementation.7 Recommended intake for endurance athletes is 500 to 800 mg daily.8 Higher doses can cause diarrhea.
In a study of athletes running 40 minutes at 70 degrees Fahrenheit, potassium loss was estimated at 435 mg/hour. The rate of potassium loss is approximately 200 mg/kg of weight lost during exercise.9 Cells release potassium into the bloodstream and serum levels rise with exercise, possibly instigating fatigue. Potassium supplementation after short events (less than two hours), and during and after long events, is warranted.10 For postactivity replacement, athletes should take about 435 mg/hour of exercise or 200 mg/kg of weight loss. As much as 150 mg/hour during activity can be tolerated by most athletes. Supplement potassium cautiously because too much too quickly can cause cardiac arrest. Supplementing with potassium during training does increase markers of recovery, primarily serum lactate and muscle hydration, but does not aid performance.10
Research shows selenium benefits athletes' immune function and helps repair cellular damage. Researchers studied the selenium supplementation effects on muscle SeGPx in 24 healthy nonsmoking males. Half took 240 mcg of sodium selenite; half took placebo. After cycling to exhaustion—durations ranged from 2.6 to 3.5 hours—the group that took selenium showed less cellular damage.12 Supplementation with 200 mcg of selenium is safe and warranted for endurance athletes.13
A prospective study was performed on 36 athletes during a three- to four-hour triathlon and 64 athletes at an ironman race, which lasts between nine and 15 hours. No athletes were hyponatremic after the shorter race, but 27 percent were hyponatremic following the ironman. An average of 17 percent of the ironman participants required medical attention, most for hyponatremia.14 Extrapolated from that study, athletes should aim for 80 to 100 mg sodium per quart of hydrating beverage and 100 to 300 mg sodium per hour from other sources.
Those who train without days off lose zinc even more quickly. In a study of cyclists, researchers looked at zinc excretion via sweat. Half of the group underwent intense training for two months. Half underwent moderate training with two to three days off per week. Both groups were studied before and after. The exercising group showed increased zinc excretion while the control group showed no increase.16 The researchers believe altered zinc metabolism coupled with increased zinc excretion and stress levels lead to fatigue and decreased endurance. Athletes should take 30 to 60 mg zinc daily.17 Zinc picolinate or monomethionate are most easily tolerated.18 Prevent Oxidative Damage
In a study of 30 top-class cyclists, five months of supplementation with natural vitamin E (alpha-tocopherol) at an 800-IU daily dose significantly decreased markers of oxidative damage to muscle tissue. However, vitamin E did not benefit athletic performance. Studies evaluating vitamin E as an ergogenic, or performance aid, show no benefit.19 One possible exception is at higher altitudes where oxidative stress is more intense. A group of six mountain climbers took 400 mg synthetic vitamin E (dl-alpha-tocopherol acetate). During exertion at altitude, they showed less output of pentane and lactic acid—both markers of oxidative damage, but not suggestive of improved athletic performance. The athletes also showed a statistically significant increase in anaerobic threshold compared to a placebo group.20 The amount of vitamin E necessary to benefit athletes is not obtainable through diet. The jury is still out on natural vs. synthetic vitamin E, but endurance athletes should take 400 to 800 IU/day. Protein and Glutamine
Endurance athletes need more protein for different reasons than strength athletes do. Endurance athletes primarily use protein for maintaining aerobic metabolism, compared with the increased tissue-repair needs of strength athletes. When intake is inadequate, the body sequesters the needed proteins from lean tissue, which gives overtrained endurance athletes a gaunt appearance. A protein deficit also impairs an athlete's recovery and wound-healing ability.14 Researchers recommend endurance athletes eat 1.2 to 1.4 g/kg of body weight/day of protein.22 For a 155-pound athlete, this means a total of 85 to 100 g protein per day. Only a few studies recommend protein intake levels as high as 2 g/kg of body weight/day.23
Oral glutamine replacement after exercise can lower infection risk. In one study, 200 runners and rowers were given placebo or 2,000 mg glutamine two hours after exercise. In the seven days following the exercise, 81 percent of the glutamine-supplemented group were infection-free compared to 49 percent in the placebo group.26 A supplement that provides 2 g glutamine daily is a wise choice for athletes in training.26 Athletes who train strenuously for competition have greater nutritional needs than sedentary people. Adequate nutrients can mean quicker recovery time, lower infection rates, less fatigue, and ultimately, can help athletes reach their desired performance levels.
References 1. Guezennec CY, et al. Is there a relationship between physical activity and dietary calcium intake? A survey in 10,373 young French subjects. Med Sci Sports Exerc 1998 May;30(5):732-9. 2. Voss LA, et al. Exercise-induced loss of bone density in athletes. J Am Acad Orthop Surg 1998 Nov-Dec;6(6):349-57. 3. Bennell KL, et al. Effect of altered reproductive function and lowered testosterone levels on bone density in male endurance athletes. Br J Sports Med 1996 Sep;30(3):205-8. 4. Eichner ER. Sports anemia, iron supplements, and blood doping. Med Sci Sports Exerc 1992 Sep;24(9 Suppl):S315-8. 5. Weaver CM, et al. Exercise and iron status. J Nutr 1992 Mar;122(3 Suppl):782-7. 6. Altura BM, et al. Magnesium depletion impairs myocardial carbohydrate and lipid metabolism and cardiac bioenergetics and raises myocardial calcium content in-vivo: relationship to etiology of cardiac diseases. Biochem Mol Biol Int 1996 Dec;40(6):1183-90. 7. Lukaski HC, et al. Micronutrients (magnesium, zinc, and copper): are mineral supplements needed for athletes? Int J Sport Nutr, 1995;5 Suppl:S74-83. 8. Seelig M. Magnesium deficiency in the pathogenesis of disease. New York: Plenum Press; 1980. 9. Wenk C, et al. Methodological studies of the estimation of loss of sodium, potassium, calcium and magnesium through the skin during a 10 km run. Z Ernahrungswiss 1993 Dec;(4):301-7. 10. Tarnopolsky MA, et al. Mixed carbohydrate supplementation increases carbohydrate oxidation and endurance exercise performance and attenuates potassium accumulation. Int J Sport Nutr 1996 Dec;(4):323-36. 11. Venditti P. Effect of training on antioxidant capacity, tissue damage, and endurance of adult male rats. Int J Sports Med 1997 Oct;18(7):497-502. 12. Tessier F, et al. Muscle GSH-Px activity after prolonged exercise, training, and selenium supplementation. Biol Trace Elem Res, 1995 Jan-Mar;47(1-3):279-85. 13. Persson-Moschos M, et al. Plasma selenoprotein P levels of healthy males in different selenium status after oral supplementation with different forms of selenium. Eur J Clin Nutr 1998 May;52(5):363-7. 14. Hiller WD, et al. Medical and physiological considerations in triathlons. Am J Sports Med 1987 Mar;(2):164-7. 15. Cordova A. Behaviour of zinc in physical exercise: a special reference to immunity and fatigue. Neurosci Biobehav Rev 1995 Fall;19(3):439-45. 16. Cordova A, et al. Effect of training on zinc metabolism: changes in serum and sweat zinc concentrations in sportsmen. Ann Nutr Metab 1998;42(5):274-82. 17. Barrie SA, et al. Comparative absorption of zinc picolinate, zinc citrate and zinc gluconate in humans. Agents Actions 1987;21(1-2):223-8. 18. Rohde T, et al. Effect of glutamine supplementation on changes in the immune system induced by repeated exercise. Med Sci Sports Exerc 1998 Jun;30(6):856-62. 19. Rokitzki L, et al. Alpha-tocopherol supplementation in racing cyclists during extreme endurance training. Int J Sport Nutr 1994 Sep;4(3):253-64. 20. Simon-Schnass I, et al. Influence of vitamin E on physical performance. Int J Vitam Nutr Res 1988;58(1):49-54. 21. Lemon PW, et al. Do athletes need more dietary protein and amino acids? Int J Sport Nutr 1995 Jun;5 Suppl:S39-61. 22. Shephard, RJ, et al. Immunological hazards from nutritional imbalance in athletes. Exerc Immunol Rev 1998;4:22-48. 23. Rohde T, et al. The immune system and serum glutamine during a triathlon. Eur J Appl Physiol 1996;74(5):428-34. 24. Newsholme EA, et al. The proposed role of glutamine in some cells of the immune system and speculative consequences for the whole animal. Nutrition 1997 Jul-Aug; 13(7-8):728-30. 25.Rohde T, et al. Effect of glutamine supplementation on changes in the immune system induced by repeated exercise. Med Sci Sports Exerc 1998 Jun;30(6):856-62. 26.Castell LM, et al. Does glutamine have a role in reducing infections in athletes? Eur J Appl Physiol 1996;73(5):488-90.
|
Athletes lose magnesium through sweat and urine. This, combined with the fact that athletes' diets are usually low in magnesium, generally leads to the need for supplementation.7 Recommended intake for endurance athletes is 500 to 800 mg daily.8 Higher doses can cause diarrhea.
In a study of athletes running 40 minutes at 70 degrees Fahrenheit, potassium loss was estimated at 435 mg/hour. The rate of potassium loss is approximately 200 mg/kg of weight lost during exercise.9 Cells release potassium into the bloodstream and serum levels rise with exercise, possibly instigating fatigue. Potassium supplementation after short events (less than two hours), and during and after long events, is warranted.10 For postactivity replacement, athletes should take about 435 mg/hour of exercise or 200 mg/kg of weight loss. As much as 150 mg/hour during activity can be tolerated by most athletes. Supplement potassium cautiously because too much too quickly can cause cardiac arrest. Supplementing with potassium during training does increase markers of recovery, primarily serum lactate and muscle hydration, but does not aid performance.10
Research shows selenium benefits athletes' immune function and helps repair cellular damage. Researchers studied the selenium supplementation effects on muscle SeGPx in 24 healthy nonsmoking males. Half took 240 mcg of sodium selenite; half took placebo. After cycling to exhaustion—durations ranged from 2.6 to 3.5 hours—the group that took selenium showed less cellular damage.12 Supplementation with 200 mcg of selenium is safe and warranted for endurance athletes.13
A prospective study was performed on 36 athletes during a three- to four-hour triathlon and 64 athletes at an ironman race, which lasts between nine and 15 hours. No athletes were hyponatremic after the shorter race, but 27 percent were hyponatremic following the ironman. An average of 17 percent of the ironman participants required medical attention, most for hyponatremia.14 Extrapolated from that study, athletes should aim for 80 to 100 mg sodium per quart of hydrating beverage and 100 to 300 mg sodium per hour from other sources.
Those who train without days off lose zinc even more quickly. In a study of cyclists, researchers looked at zinc excretion via sweat. Half of the group underwent intense training for two months. Half underwent moderate training with two to three days off per week. Both groups were studied before and after. The exercising group showed increased zinc excretion while the control group showed no increase.16 The researchers believe altered zinc metabolism coupled with increased zinc excretion and stress levels lead to fatigue and decreased endurance. Athletes should take 30 to 60 mg zinc daily.17 Zinc picolinate or monomethionate are most easily tolerated.18 Prevent Oxidative Damage
In a study of 30 top-class cyclists, five months of supplementation with natural vitamin E (alpha-tocopherol) at an 800-IU daily dose significantly decreased markers of oxidative damage to muscle tissue. However, vitamin E did not benefit athletic performance. Studies evaluating vitamin E as an ergogenic, or performance aid, show no benefit.19 One possible exception is at higher altitudes where oxidative stress is more intense. A group of six mountain climbers took 400 mg synthetic vitamin E (dl-alpha-tocopherol acetate). During exertion at altitude, they showed less output of pentane and lactic acid—both markers of oxidative damage, but not suggestive of improved athletic performance. The athletes also showed a statistically significant increase in anaerobic threshold compared to a placebo group.20 The amount of vitamin E necessary to benefit athletes is not obtainable through diet. The jury is still out on natural vs. synthetic vitamin E, but endurance athletes should take 400 to 800 IU/day. Protein and Glutamine
Endurance athletes need more protein for different reasons than strength athletes do. Endurance athletes primarily use protein for maintaining aerobic metabolism, compared with the increased tissue-repair needs of strength athletes. When intake is inadequate, the body sequesters the needed proteins from lean tissue, which gives overtrained endurance athletes a gaunt appearance. A protein deficit also impairs an athlete's recovery and wound-healing ability.14 Researchers recommend endurance athletes eat 1.2 to 1.4 g/kg of body weight/day of protein.22 For a 155-pound athlete, this means a total of 85 to 100 g protein per day. Only a few studies recommend protein intake levels as high as 2 g/kg of body weight/day.23
Oral glutamine replacement after exercise can lower infection risk. In one study, 200 runners and rowers were given placebo or 2,000 mg glutamine two hours after exercise. In the seven days following the exercise, 81 percent of the glutamine-supplemented group were infection-free compared to 49 percent in the placebo group.26 A supplement that provides 2 g glutamine daily is a wise choice for athletes in training.26 Athletes who train strenuously for competition have greater nutritional needs than sedentary people. Adequate nutrients can mean quicker recovery time, lower infection rates, less fatigue, and ultimately, can help athletes reach their desired performance levels.
References 1. Guezennec CY, et al. Is there a relationship between physical activity and dietary calcium intake? A survey in 10,373 young French subjects. Med Sci Sports Exerc 1998 May;30(5):732-9. 2. Voss LA, et al. Exercise-induced loss of bone density in athletes. J Am Acad Orthop Surg 1998 Nov-Dec;6(6):349-57. 3. Bennell KL, et al. Effect of altered reproductive function and lowered testosterone levels on bone density in male endurance athletes. Br J Sports Med 1996 Sep;30(3):205-8. 4. Eichner ER. Sports anemia, iron supplements, and blood doping. Med Sci Sports Exerc 1992 Sep;24(9 Suppl):S315-8. 5. Weaver CM, et al. Exercise and iron status. J Nutr 1992 Mar;122(3 Suppl):782-7. 6. Altura BM, et al. Magnesium depletion impairs myocardial carbohydrate and lipid metabolism and cardiac bioenergetics and raises myocardial calcium content in-vivo: relationship to etiology of cardiac diseases. Biochem Mol Biol Int 1996 Dec;40(6):1183-90. 7. Lukaski HC, et al. Micronutrients (magnesium, zinc, and copper): are mineral supplements needed for athletes? Int J Sport Nutr, 1995;5 Suppl:S74-83. 8. Seelig M. Magnesium deficiency in the pathogenesis of disease. New York: Plenum Press; 1980. 9. Wenk C, et al. Methodological studies of the estimation of loss of sodium, potassium, calcium and magnesium through the skin during a 10 km run. Z Ernahrungswiss 1993 Dec;(4):301-7. 10. Tarnopolsky MA, et al. Mixed carbohydrate supplementation increases carbohydrate oxidation and endurance exercise performance and attenuates potassium accumulation. Int J Sport Nutr 1996 Dec;(4):323-36. 11. Venditti P. Effect of training on antioxidant capacity, tissue damage, and endurance of adult male rats. Int J Sports Med 1997 Oct;18(7):497-502. 12. Tessier F, et al. Muscle GSH-Px activity after prolonged exercise, training, and selenium supplementation. Biol Trace Elem Res, 1995 Jan-Mar;47(1-3):279-85. 13. Persson-Moschos M, et al. Plasma selenoprotein P levels of healthy males in different selenium status after oral supplementation with different forms of selenium. Eur J Clin Nutr 1998 May;52(5):363-7. 14. Hiller WD, et al. Medical and physiological considerations in triathlons. Am J Sports Med 1987 Mar;(2):164-7. 15. Cordova A. Behaviour of zinc in physical exercise: a special reference to immunity and fatigue. Neurosci Biobehav Rev 1995 Fall;19(3):439-45. 16. Cordova A, et al. Effect of training on zinc metabolism: changes in serum and sweat zinc concentrations in sportsmen. Ann Nutr Metab 1998;42(5):274-82. 17. Barrie SA, et al. Comparative absorption of zinc picolinate, zinc citrate and zinc gluconate in humans. Agents Actions 1987;21(1-2):223-8. 18. Rohde T, et al. Effect of glutamine supplementation on changes in the immune system induced by repeated exercise. Med Sci Sports Exerc 1998 Jun;30(6):856-62. 19. Rokitzki L, et al. Alpha-tocopherol supplementation in racing cyclists during extreme endurance training. Int J Sport Nutr 1994 Sep;4(3):253-64. 20. Simon-Schnass I, et al. Influence of vitamin E on physical performance. Int J Vitam Nutr Res 1988;58(1):49-54. 21. Lemon PW, et al. Do athletes need more dietary protein and amino acids? Int J Sport Nutr 1995 Jun;5 Suppl:S39-61. 22. Shephard, RJ, et al. Immunological hazards from nutritional imbalance in athletes. Exerc Immunol Rev 1998;4:22-48. 23. Rohde T, et al. The immune system and serum glutamine during a triathlon. Eur J Appl Physiol 1996;74(5):428-34. 24. Newsholme EA, et al. The proposed role of glutamine in some cells of the immune system and speculative consequences for the whole animal. Nutrition 1997 Jul-Aug; 13(7-8):728-30. 25.Rohde T, et al. Effect of glutamine supplementation on changes in the immune system induced by repeated exercise. Med Sci Sports Exerc 1998 Jun;30(6):856-62. 26.Castell LM, et al. Does glutamine have a role in reducing infections in athletes? Eur J Appl Physiol 1996;73(5):488-90.
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A balanced diet for runners
August 9, 2009
Filed under Diet And Nutrition, Running
.jpg "A balanced diet for runners")
Top nutrition tips to get you started in running
Getting fit and active through a running training programme is a great way of keeping your body and mind fit and healthy. However, a balanced run training plan also requires a balanced diet, to ensure you have the right energy intake to suit your body's running workouts. Here's the realbuzz introduction to running nutrition, guiding you on the best things to eat if you're looking to build those all-important running energy reserves.
We are all becoming more aware of the physiological and psychological rewards of being physically active, notably through running. If you need to lose weight or want to avoid becoming overweight, then the best way is to increase your physical activity levels, and to reduce your dietary fat intake, which can be achieved by decreasing your intake of starchy and sugary carbohydrates.
Even if you didn’t lose weight, but became fitter, it would help you avoid the many health complications of being overweight and so increase your life quality and expectancy. Furthermore, taking part in regular running exercise or other sports also helps reduce your risk of developing heart disease, diabetes, osteoporosis and certain forms of cancer. And, not forgetting the important role that physical activity plays in your mental well-being.
So, the recommendation that everyone should accumulate 30 minutes or more of physical activity over the course of most days of the week is thoroughly justified. But how do we go about becoming more active? If you’re pretty sedentary at the moment, then what you need to do is to modify your lifestyle to build in more running or other physical activities.
So start by becoming less sedentary, for example decreasing the time you spend watching television, surfing the net or playing computer games. Next try to be more active, take the stairs instead of the lift, park further away from the supermarket, or get off the bus one stop earlier and walk the rest of the way. Then gradually add some sustained exercise to your daily routine, such as brisk walking, cycling or swimming.
Yes, the aim is to be doing at least 30 minutes of continuous exercise five days per week, but gradual is the key, so try three lots of ten minutes to start with, and take it from there. The next question is – how do we fuel these bursts of running and other physical energy?
Dietary considerations for runners
The dietary considerations for fuelling a healthy, active lifestyle can be found in more detail in the following sections, but here are the basics.
As we know, a healthy balanced diet is essential for good health. The key to making our diet healthy and balanced is simply everything in moderation, plus extra carbohydrates if you’re running or exercising.
But why the emphasis on carbohydrates? Well, no matter what type of exercise or running you do, your body will always use some glucose for energy. Glucose is formed from the breakdown of carbohydrates – the sugars and starches in your diet – and is stored as glycogen. However, the body can only store a limited amount of glycogen, so the stores need to be kept topped-up to avoid fatigue. If you don’t eat enough carbohydrates, but continue to exercise you will soon become sluggish and dizzy and your exercise goals will go right out the window!
The more physical activity you do, the more glucose your body uses, the more carbohydrates you need to consume to replenish your stores. Therefore, physically active people need to consume a diet where more than half of it comes from carbohydrate foods. The bulk of your carbohydrate intake should come from the starchy sources such as bread, rice, potatoes and pasta and the remaining from more sugary sources such as sugar, fruit and juices.
However, as most carbohydrate foods, for example pasta or sugars, are eventually broken down into glucose, one type is not necessarily better than the other. But, if you’re running regularly, you need to eat a lot of carbohydrates, and there is only so much bread and pasta you can eat, so this is where sugary snacks and drinks have a useful role to play, both in providing you with energy before you exercise, and in helping you restock your glucose stores after exercise, ready for your next bout of physical activity or your next big run.
Although you need to allow two to three hours after a large meal before exercising, a high carbohydrate snack within 30 minutes of training has several benefits. Eating 25-50g of rapidly absorbed carbohydrate just before exercise will not only improve performance, but will also help maintain your blood sugar levels and so prevent you feeling light-headed. There are plenty of portable high carbohydrate snacks to choose from – bagels, honey or jam sandwiches, cereal bars, bananas, watermelon, dried fruit, jelly beans, juice or a sports drink – so find something you fancy.
Hydration for Runners
August 9, 2009
Filed under Diet And Nutrition, Running
A good hydration strategy is an essential part of every runner's preparation for training and events.
Commercial sports drinks have been developed on sound scientific principles, and runners can turn this science into optimal performance and well-being by learning the practical aspects of what to consume during their event.
They also need to look at the timing of consumption and the amounts needed for optimum performance. Just as general training and competition strategies should be tailored for individual runners in accordance with their unique needs and preferences, so should their drinking and eating choices before and during exercise.
It is important for runners to identify their own winning formula, and to know how to manipulate this in hot or cold environments.
Key principles:
- Limit dehydration during training and events by drinking water or a sports drink;
- Get a feel for sweat rates during exercise so that drink practices can be adjusted accordingly. It is not necessary to drink enough to prevent loss of body weight, but the amount of dehydration should be normally limited to a loss of less than 2% of body weight (i.e., 1kg for 50kg person, 1.5kg for a 75kg person, and 2kg for a 100kg person);
- Since the negative effects of dehydration on high intensity performance are greater in warm environments, upgrade drinking practices in these conditions to minimise the overall fluid deficit. This may mean drinking before and during longer runs;
- Don't drink at rates that are greater than sweat losses so that you actually gain weight.
When do you need more than Water?
The provision of additional fuel to the muscle or brain can be of benefit to any event lasting longer than about one hour, which would otherwise result in fatigue. The intake of carbohydrate that is generally associated with performance benefits is from 20-60g per hour.
The use of sports drinks with a carbohydrate content of about 4-8% (4-8 g/100 ml) allows carbohydrate and fluid needs to be met simultaneously in most events.
Intake of a carbohydrate-containing drink may provide performance benefits for distance running.
Consuming a carbohydrate-containing drink (or light foods) may help to maintain skills and judgment when middle and long distance runners become fatigued.
Sodium should probably be included in fluids consumed during training sessions or events lasting longer than one to two hours.
Caffeine is present in many commonly available beverages and foods, and can enhance both physical and mental performance. This benefit can be obtained with the relatively small doses of caffeine that are commonly consumed by people of various cultures (e.g. about 1.5mg/kg of body weight, as found in a small cup of brewed coffee or 500-750ml of a cola beverage).
How to estimate Sweating Rate
Measure body weight both before and after at least one hour of strenuous exercise. These readings should be made with the runner wearing minimal clothing and while bare footed. The post-exercise reading should be taken as soon as is practical after the session, and after toweling dry.
Note the volume of fluid consumed during exercise (litres).
Calculations:
Sweat loss (litres) = Body weight before exercise (kg) – Body weight after exercise (kg) + fluid consumed during exercise (litres)
To convert to a sweat rate per hour, divide by the exercise time in minutes and multiply by 60.
Note: 2.2 pounds equals 1kg and converts to a volume of 1litre or 1,000ml or 34 ounces of water.
Rehydration after Exercise
Recovery after exercise is part of the preparation for the next exercise session, and replacement of sweat losses is an essential part of this process. Both water and salts lost in sweat must be replaced.
Aim to drink about 1.2-1.5litres of fluid for each kg of weight lost in training or during an event.
Drinks should contain sodium (the main salt lost in sweat) if no food is eaten at this time. Sports drinks that contain electrolytes are helpful, but many foods can also supply the salt that is needed. A little extra salt may be added to meals when sweat losses are high, but salt tablets should be used with caution.
Try out new plans for fluid and fuel replacement during training – never introduce a new regime during an event.
12 Reasons You’re So Tired and How to Bounce Back
When people ask you how you are, how do you respond? Do you say you're fine—or tired?
If you were too exhausted even to answer the question, you're not alone: Fatigue is endemic these days. Here are a dozen potential reasons behind that run-down feeling and how you can re-energize yourself.
1. You're bored.
Boredom happens when parts of your life have created a rut of routine, says clinical psychologist Judith Sills, Ph.D. "There's not enough zap in your brain," she says. Sills, author of The Comfort Trap (Viking, 2004), concedes that humans are creatures of habit, so routines are essential for life. But comforting routines and habits can become deadening. That's when lack of zing can translate into fatigue. There's a loss of energy when you have nothing to stimulate you, she says.
The fix: Do something new, Sills suggests. Even small changes, such as a two-day getaway, can be life-affirming. "There's a clear link between our emotions and the anticipation of satisfaction and physical energy," she says. Changing your routine also helps. Try driving down a different road or eating food you haven't tried before. "When you take in new information, your spirit feels a sense of possibility," says Sills. "It's mind food."
2. You have allergies.
Think of allergies as the body's way of fighting unwanted guests. The trouble starts when allergens, such as pollen, certain foods, or animal dander invade the mucous membranes of the eyes and throat, says Lily Pien, M.D., an allergist at The Cleveland Clinic. This triggers the body's antibodies to fight the invaders, causing a release of histamines. The body's reaction to the allergens is often excessive, leading to sneezing, shortness of breath or itching. "It's these reactions that wear you down, especially when they keep you from sleeping." she says.
The fix: "Don't misdiagnose yourself," says Pien, "Most people are allergic to more than one substance." She advises seeing an allergist and getting a skin test to determine the allergens that may be affecting you. Antihistamines and nasal steroid sprays are both typical treatments, she says, and adds that 20 percent of the U.S. population suffers from allergies.
3. You're over-caffeinated.
It seems like a contradiction, but caffeine, a stimulant to the central nervous system, can actually make you tired, says Cheryl Forberg, a registered dietician and the author of Positively Ageless: a 28-Day Plan for a Younger, Slimmer, Sexier You (Rodale Books, 2008). A once-a-day dose in the morning in tea or coffee is fine, she says. But people can create a vicious cycle when they keep ingesting more caffeine to counteract the exhaustion they feel after the previous dose wears off. And, she adds, the cumulative effects of the day's caffeine—such as increased heart rate and a rise in blood pressure—can also keep you from getting a good night's sleep.
The fix: Consider antioxidant-rich green tea, says Forberg. A cup of green tea contains 50 mg of caffeine, compared to coffee's 137 mg and black tea's 65 mg. Not eating or drinking high-caffeine foods and drink—including dark chocolate and certain soft drinks—from late afternoon on is also a step towards restful sleep. Keeping caffeine to a minimum is the best way to go, she says.
4. You're multi-tasking.
Doing one thing at a time is a luxury for most people. But multi-tasking has its downside. "When you multi-task, you need to switch back and forth from one project to another and monitor all the projects simultaneously," says Neal Roese, Ph.D., a professor of psychology at The University of Illinois at Urbana-Champaign. Multi-tasking is a big drain on glucose, which fuels everything the brain does, he says. Not surprisingly, studies show that too much flitting from one task to another ultimately leads to errors and fatigue. Ingesting sugar may keep you going temporarily, but eventually you crash.
The fix: The trick, says Roese, is to keep your projects down to a minimum; he suggests no more than three at a time. Prioritizing your projects and taking the short frequent breaks that allow glucose levels to be restored are also useful strategies.
5. You're anemic.
People with anemia typically don't have enough red blood cells in their body. And, because these blood cells are the body's transportation system for oxygen, fewer of these cells mean less oxygen makes its way to the cells—including that of the brain. "People whose cells get less oxygen may be less able to concentrate and they may feel less energetic, says Alan Greene, M.D., clinical professor of pediatrics at Stanford University and the author of Raising Baby Green (Jossey-Bass, 2007). The most typical type is iron-deficiency anemia, but loss of blood cells through internal bleeding can also be a cause. He says anemia is especially harmful to children, who need the oxygen to fuel their developing bodies and brains.
The fix: Greene advises taking a blood test. On a complete blood count (CBC) test, a low hematocrit indicates anemia (hematocrit measures what proportion of blood volume is made up of red blood cells). Testing serum ferritin, a measure of the body's iron stores, can detect iron deficiency, which can cause symptoms even before full-blown anemia develops. Eating iron-rich foods like lean meat, poultry and beans can help increase the supply, especially when accompanied by foods high in vitamin C. Greene also suggests women and children take supplements that contain iron. Men should speak with their physicians first before taking iron supplements, as their bodies don't easily excrete any excess, and too much of the mineral can also be a cause of fatigue.
6. You have poor posture.
Standing up straight looks impressive and, it turns out, has health benefits. If you hunch your shoulders forward, don't equally distribute your weight on both feet, or create an inward curve in your lower back, you're setting yourself up for fatigue, says Kathleen Koch, an exercise physiologist at The Cleveland Clinic. That's because it's harder for blood to nourish muscles that are being held in inefficient positions typical of bad posture. "Reduced blood flow means your heart and lungs have to work harder, and this makes you tired," she says. Sitting improperly and even running with poor form has the same effect.
The fix: Koch suggests strength and core training to address poor posture. For example, she says to correct slouched shoulders—a sign that the chest muscles are disproportionately stronger—you need to strengthen the muscles in the upper back. Because poor posture is a good indicator of muscle imbalance, it's important to train all muscle groups equally, she says.
7. You have an underactive thyroid.
One of the top medical reasons for a slow metabolism and low energy is hypothyroidism, says Nunilo Rubio Jr., M.D., assistant professor of endocrinology at The University of Texas Medical School at Houston. Women are more predisposed to the condition, which is from the thyroid gland's secreting less of its hormones. This, in turn, causes fatigue, as well as weight gain, intolerance to cold, and dry hair and skin. Rubio calls it the "turtle effect." Unfortunately, in most cases, it's the body's own autoimmune response that's to blame. The antibodies involved gradually can damage and, in some cases, destroy the thyroid, a condition known as Hashimoto's thyroiditis. In severe cases, says Rubio, metabolism slows down so dramatically that the patient usually requires an intravenously administered dose of thyroid hormones.
The fix: Rubio suggests those suffering from fatigue ask their physician for a blood workup to determine the level of thyroid- hormone activity. If you're diagnosed as having hypothyroidism, a doctor will typically start thyroid-hormone replacement therapy. Once thyroid-hormone levels are restored, energy usually returns to previous levels. (Although iodine deficiency is often linked to hypothyroidism, most people in the U.S. get adequate amounts by using iodized salt and eating iodine-containing food.)
8. You have undiagnosed heart disease.
A heart that's unable to pump blood efficiently has to work harder to transport oxygen throughout the body. Fatigue is the result, says Nieca Goldberg, M.D., cardiologist and author of Dr. Nieca Goldberg's Complete Guide to Women's Health (Ballantine Books, 2008). Several conditions can cause the heart to overexert itself, including clogged arteries, high blood pressure and heart-valve problems. Typically, fatigue due to undiagnosed cardiovascular condition manifests after exertion.
The fix: If you've ruled out anemia, hypothyroidism and infection, and you still feel tired, it's important to get diagnosed for potential heart problems, says Goldberg. Tests typically include an echocardiogram to see how the blood is pumped through the heart, and a stress test to reveal arterial blockages. Not pinpointing heart disease as early as possible can mean more severe symptoms over time, such as shortness of breath and fluid build-up.
9. You're not exercising enough.
It seems counterintuitive that doing nothing can make you fatigued, but it's true. "If you move, you'll feel less tired," says Dr. Koch of The Cleveland Clinic. When you're sedentary, she says, your metabolic rate decreases and you burn fewer calories, so you feel exhausted. Exercise gets that metabolic rate up, which means more energy, and not only the physical kind. People who say they're tired are often depressed, says Koch. Exercise increases the production of dopamine, a hormone that's a mood enhancer.
The fix: Literally, start with small steps. Koch says that research confirms that even a 10- to 15- minute daily walk provides cardiovascular health benefits But, she advises, don't forget to include strength training in the mix, which helps build lean muscle mass. Overall, increasing your amount of weekly exercise means you'll be able to burn even more calories, she says. And that means even more energy at your disposal.
10. You're dehydrated.
At least half of our bodies and 92 percent of our blood consist of water. "Water serves as a medium for the body to perform its life-sustaining functions, such as regulating body temperature and eliminating waste," says Toby Amidor, a registered dietician in New York City. "If you don't ingest enough water to help these metabolic reactions occur, you'll become tired or lightheaded."
The fix: At the first sign of thirst or dizziness, all you need is a small amount of liquid, as little as half a cup or water or fruit juice, says Amidor. Although many people drink huge quantities of water daily as a matter of course, she says many experts now suggest that people simply heed the body's signals for hydration. The water in fruits and vegetables also count as part of your intake, says Amidor. The caveat, though, is that older people often lose their sense of thirst and need to be reminded to hydrate on a more regular basis. For the rest of us, making sure we have access to water as needed—in portable non-plastic containers—is a good option.
11. You're pre-diabetic.
Glucose supplies energy to the body and brain. It's not surprising that not enough glucose will make you extremely tired. But the same is true when you ingest too much, says Dr. Greene. Normally, the act of eating signals the body to produce insulin which, in turn, fuels the cells with energy. But, says Greene, when you're pre-diabetic, your body can become insulin-resistant—overeating or ingesting too many simple carbs is often a factor. The result is all that excess glucose doesn't get into the cells, but rather it gets stored as fat or spills into the urine, and you grow tired.
The fix: A fasting blood sugar test will determine if you're pre-diabetic, says Greene. If you fall into that category, consider it a wake-up call to change your eating and exercise habits. Greene recommends a Mediterranean-type diet, consisting of whole grains, lots of fruits and vegetables and moderate amounts of healthy fats.
12. You have sleep apnea.
Many people with sleep apnea don't even know they have it, says Michael Breus, Ph.D., a clinical psychologist in private practice whose specialty is sleep disorders. Sleep apnea, which is typically caused by anatomical problems, impels the sleeper to stop breathing, sometimes as many as 150 times an hour. When breathing shuts down, even for only a couple of seconds, there's less oxygen supplied to the brain. The body senses the danger and wakes you to breathe. "In severe cases, this constant waking is comparable to total sleep deprivation," says Breus, who's author of Beauty Sleep: Look Younger, Lose Weight and Feel Great through Better Sleep (Plume, 2007).
The fix: See a medical professional who's certified in sleep medicine or clinical sleep disorders, says Breus. You'll be referred to a sleep center for diagnosis. The most popular form of treatment is a continuous positive airway pressure machine (CPAP), which shoots air through the nasal passages and throat while you're asleep. Other solutions include using nose filters, dental appliances to help correct jaw displacement, or surgery to remove excess throat tissue which tends to accumulate in overweight people. Weight loss may eliminate the condition entirely in some cases, says Breus.
Source: Coeli Carr for MSN Health & Fitness
Jogging/Running Frequency – The Balance Between Fitness And Risking Injury
August 8, 2009
Filed under Running
Have you ever wondered how much is too much exercising? We know that fitness level is a function of how often we exercise, how long we do it and at what intensity level we workout. You may have often come across the banal ‘thrice a week for 30 minutes’ phrase. There is research-backed reason for this lower limit. However, there are upper limit cautions as well.
As per the ACSM (American College of Sports Medicine), each session should ideally last from 20 to 60 minutes (duartion) and should be performed 3 – 5 days a week (frequency) at a an intensity level measured by heart rate (60%-90%).
In the first 15 minutes of aerobic activity, glycogen within the muscles is used to provide energy for the workout. Fat metabolism for energy does not begin about 15-20 minutes after the exercise has begun. Taking a margin for level of intensity of your workout and your weight and body type, the lower bar has been set to 30 minutes minimum for workouts.
Aerobic activities longer than an hour also contribute to burning fat. However, the rate of burning fat reduces after the first one hour. Also, the chances of injury caused by fatigue increases exponentially beyond the 1-hr mark. Aerobic activity more than 5 times a week is also risky for similar reasons besides it not getting adequate rest facilitating recovery to tissue and muscles. Listen to your body signals, rest, sleep and eat well in the non-workout days.
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