If my toenails are breaking off whenever I start running outside again, should I get new running shoes?
June 29, 2010
Filed under Running Answers
When I first ran track I had my first experience with losing a toenail, as disgusting as that sounds. It was only the pinky toe though- no harm done. It’s happened to my pinky toes about 2 more times. I just started running again a few days ago but it was my middle toe that has had to be pulled off. Should I get new shoes? Or is it just my anemia?
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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.
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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.
|
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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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
What about Caffeine and Athletes
August 5, 2009
Filed under Diet And Nutrition
By Stephanie Nunes, RD
There is much confusion on the health effects of caffeine. I am going to address specific topics that may be of interest to athletes: Dehydration, Bone Health, Sports Performance, Cancer, and Heart Disease.
Extensive research has been conducted on the health effects and safety of caffeine consumption and the general consensus appears to be that moderate caffeine consumption (approximately 300mg/day) is safe. It is estimated that the average daily caffeine consumption among Americans is 280mg/day.
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A Few Common Sources of Caffeine |
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| Source | Caffeine |
| 8 oz Brewed Coffee | 135 mg |
| 1 oz Expresso | 30-50 mg |
| 8 oz Green Tea | 25-40 mg |
| 8 oz Black Tea | 40-70 mg |
| 12 oz Coca-Cola | 34.5 mg |
| 12 oz Diet Coke | 46.5 mg |
| 12 oz Mountain dew | 55.5 mg |
| SoBe No Fear | 158 mg |
| 1.45 oz Sweet chocolate bar | 27 mg |
| Exedrin | 65 mg |
Dehydration
Researchers used to believe that caffeinated beverages had a diuretic effect and caused dehydration. Recent research now shows that coffee, tea, and other caffeine-containing beverages do not affect hydration status on those who are already accustomed to consuming caffeine. Caffeine only has a diuretic effect if you consume large amounts of it (500-600 mg/day).
My advice: Enjoy your favorite caffeinated beverage while continuing to focus on maintaining proper hydration with fluids such as water, juices, sports drinks, etc.
Bone Health Research has shown that caffeine is not a significant risk factor for poor bone health when adequate calcium is consumed.
My Advice: Include at least 2 servings of calcium rich foods daily and add milk to your coffee or tea (my favorite is a non-fat mocha!)
Sports Performance
Early researchers thought caffeine's benefit on sports performance was linked to its ability to spare muscle glycogen and increase fatty acid metabolism. Now the current thinking is that the positive effects of caffeine have more to do with "mental energy". Studies on sports performance have shown that caffeine had a 24% improvement in endurance performance and 4% improvement in strength performance. The quantity used which showed the biggest improvement was 6 mg/kg body weight. Less than 3 mg/kg showed a smaller improvement or no improvement at all. It is also thought by some that the amount of caffeine needed for sports performance depends partly on "caffeine sensitivity".
Additional Note: Substances in coffee and tea can interfere with iron absorption.
My Advice: If you suffer from anemia, do not drink tea or coffee with your meals or within one hour after. The best advice would be to drink them an hour before eating. If you don't usually use caffeine but want to try it for sports performance, watch for stomach distress.
Cancer
The American Institute for Cancer Research (AICR) recently released an article, "The Truth about Caffeine and Cancer". The AICR stated that coffee is no longer associated with increased cancer risk. In fact, "because it contains antioxidants and anti-inflammatory compounds, coffee may actually boost health and possibly reduce cancer risk." Tea continues to show cancer combating benefits, especially green tea.
Heart Disease
Recent research has shown no relationship between caffeine ingestion and heart disease. However, there can be exceptions to this rule in that some may react differently to caffeine than others.
My Advice: Check with your physician if you are experiencing elevated blood pressure or arrhythmias.
Summary:
Caffeine beverages can be worked into an athletes meal plan as long as you pay attention to overall daily hydration, continue to eat/drink the recommended calcium products, and follow an overall balanced meal plan that meets your sports- specific nutrient needs.
Stephanie Nunes is a Registered Dietitian and runner residing in San Luis Obispo, California. Her private practice is "Rock Solid Nutrition" and she provides individual counseling, on-line counseling, lectures or presentations for specific groups, and nutrition related articles. If you would like to contact Stephanie for any of these services, her e-mail address is Rocksolidnutrition@sbcglobal.net.
Detox Diets 101: Keeping Your body in Shape through Proper eating
May 17, 2009
Filed under Diet And Nutrition
If you’re feeling sluggish, or you think you’re always full and the food has settled in your stomach, undigested. If you think you’re fat and need to lose weight. And if you think that you’ve ingested more than the allowed preservatives and additives into your body and your liver’s starting to show symptoms of abuse, then it’s time for you to go on a Detox program.
Detox or detoxification is the process of neutralizing or eliminating toxins from the body. Detox plans may be in different forms and ways – from regular exercise to body scrubs and spa massages, to yoga and meditation. But the simplest and the most common perhaps is to go on a detox diet.
A detox diet is a program that minimizes the chemicals ingested into the body by going for organic food. It highlights food like vitamins and antioxidants that the body needs for detoxification. It also involves taking in of food that will aid in the elimination of toxins like high fiber food and water. It generally suggests a high intake of fresh vegetables, fruits, beans, nuts and lots of fluids, while cutting down on caffeine, alcohol, yeast and sugars.
So why go for a detox diet? If you’re a regular fast food chain eater, you’ve probably ingested many fat-soluble chemicals contained in the French fries, cheeseburgers, twisters and soft drinks you’ve consumed. An ‘overload’ of these chemicals in the body can lead to illness and conditions like liver malfunction, kidney problems, hormonal imbalance, nutritional deficiencies and inefficient metabolism. And the most common symptoms of these illnesses are the usual fatigue, poor skin and low tolerance to pain.
By going on a detox diet, people would have improved energy, clearer and fairer skin, a regular bowel movement, improved metabolism and digestion, increased concentration. Generally, it spells wellness and a better well-being.
A word of caution…though anyone is allowed to take on a detox diet, pregnant women or those who are nursing are cautioned not to go on such plans as they need the necessary nutrient for nursing. And unless recommended by a doctor, people with anemia, eating disorders, heart disease, low immunity, low blood pressure, ulcers, cancer, the underweight or those suffering from alcohol or drug dependency should try on a detox diet. Furthermore, such detox diet programs should be properly planned with the doctor and a nutritionist.
Other Things You Need to Know
Side effects may occur within the first few days of starting the detox diet. There’s headache and a general feeling of weakness as the body is adjusting to the change in food intake. So it is recommended to start your diet plan gradually or on Fridays when you won’t be doing much physical activity or requiring much energy. Others may experience diarrhea as the body eliminates the toxins, so take care not to be dehydrated. Drink plenty of water.
Take note that such detox diet programs should not be done for a long time. They are normally recommended to be done at least one to two times a year, and should be done during the warm months.
If you’re thinking of getting started, make sure you consult a doctor or a nutritionist. Read up on detox diets and seek advice from the experts. Remember: Too much is bad. After all, you’re doing it to improve your health, not ruin it!
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