Everything You Know About Marathons Is Wrong

 

A researcher reported recently that he could find no relationship between dehydration and cramping.

By GINA KOLATA

Most runners have heard the marathon lore: Your time will be best if the weather on race day is about 55 degrees and overcast, or even drizzly. And avoid dehydration at all costs, because it will cause your muscles to cramp and you could collapse at the finish line.

But none of that is true, researchers said at a recent marathon medicine and science conference in Chicago.

The weather theory “needs adjusting,” said Scott J. Montain, a research physiologist at the United States Army Research Institute of Environmental Medicine in Natick, Mass.

“Most of what we know comes from the lay literature,” he said.

Thousands of runners are no doubt monitoring the weather forecast for Sunday, when the New York City Marathon makes its annual tour of the five boroughs. (As of yesterday, it looked promising, with temperatures expected to be in the upper 40’s and partially cloudy skies.) But the weather nostrums for marathoning that are cited so authoritatively in journal articles and textbooks are not always borne out in legitimate science. Montain and his colleagues set out to conduct a proper study.

They gathered data from 28 years of the New York City Marathon, 35 years of the Boston Marathon and 23 years of the marathons in Hartford, Vancouver, Duluth, Minn., and Richmond, Va. The routes for those marathons have barely changed over the years, and each had a large field — more than 10,000 runners. The investigators looked at the average times for the top three men and women, and at the times for the runners who placed 25th, 50th, 100th and 300th.

Elite runners ran fastest in the coldest conditions — 41 to 50 degrees. But the slowing effect with heat was not as great as had been previously reported. For every five-degree increase in temperature, times slowed by 0.4 percent.

Warmer weather had a greater effect on slower runners. On a 77-degree day, an elite runner would be about 5 percent slower than on a 41-degree day. But a runner who finished in three hours on a 41-degree day would be slowed by about 12 percent on a 77-degree day, finishing in 3 hours 21 minutes.

One reason, Montain said, could be that slower runners spend more time on the course, and the temperature generally rises through the day. Or it could be because slower runners tend to run with a larger pack. A tightly clustered group of runners generates heat and blocks it from dissipating.

Montain and his colleagues also looked at whether marathon times were better under sunny or overcast skies. Only 13 percent of records were set on cool and cloudy days.

“It is more likely that a record will be set when it is sunny or when there are scattered clouds,” Montain said. He is not sure why that is; perhaps sunny conditions put runners in a better mood, he suggested.

Then there is the issue of cramping, that often excruciating, spasmodic, involuntary contraction of muscles that can occur during or, more often, just after a marathon. It almost always involves the muscles that were used to run — the hamstrings or calf muscles, for example. And it can last a minute or two — or much longer.

Conventional wisdom says cramps are caused by dehydration and that the solution is to consume salt and drink more fluids. Not true, says Martin P. Schwellnus, a professor of sports medicine at the University of Cape Town in South Africa.

At the conference in Chicago last month, he reported that he could find no relationship between dehydration and cramping. He has studied cyclists, marathoners and triathletes, measuring levels of electrolytes and body-weight changes, both of which are indicators of dehydration. Those who cramped were no different from those who did not.

Two other studies looked at how much weight ultramarathon runners and triathletes lost during races — a measure of fluid loss and a direct indicator of dehydration. Those who cramped lost no more weight than those who did not. If anything, Schwellnus said, those who did not have cramps were slightly more dehydrated.

The cause of cramps, Schwellnus believes, is an alteration in the electrical signals going to exhausted muscles so that the balance between those signals activating muscles and those inhibiting them is distorted. One way to protect yourself is with proper marathon training and proper pacing. “Racing at too high of an intensity is one of the single most important risk factors,” Schwellnus said.

When muscles cramp, there is a simple and effective treatment: stop running and stretch that muscle. And, Schwellnus said, realize that the cramping will soon stop.

“Almost no matter what you do, if you stop the activity, the muscle will come back to normal,” he said.

Beyond the finish line of every marathon are runners who feel dizzy, and some of them collapse. It is not as common as muscle cramps, but the condition can afflict up to about 5 percent of marathon runners, said Michael N. Sawka, head of the thermal and mountain medicine division at the United States Army Research Institute of Environmental Medicine. He wondered whether the cause could be dehydration, a commonly evoked mechanism.

Sawka looked at published studies. One compared 45 athletes who collapsed after an ultramarathon to 65 who completed the race and did not collapse. There were no obvious differences between the two groups: their body temperatures were the same (dehydration makes the temperature rise), as were their electrolyte levels. But those who collapsed were pushing themselves as hard as they could, were at or close to their personal records, or were medal winners in the race. Perhaps, Sawka said, “that final effort might contribute to collapse.”

The actual cause, though, does not appear to be dehydration, Sawka said. Instead, it is a pooling of blood in the lower legs and feet when vigorous exercise suddenly stops and the heart rate slows markedly.

Timothy Noakes, a professor of exercise and sports science at the University of Cape Town, said he had stopped giving intravenous fluids to collapsed runners.

“We completely changed the way we treat patients,” Noakes said. “All we do is have them lie down and put their feet higher than their head.”

Postmarathon collapse, Noakes added, “is a benign condition.”

“Just lift their legs and you will help the majority of patients,” he said. “That’s all you need to do to make most people recover very, very quickly. You can infuse as much fluid as you want, and you will not get the same response.”

 

Insoles Reduce Impact for Runners

MADISON – For many, running isn’t merely a sport or hobby. For the avid, running is an intricate system of punishments and rewards. And the rewards – health, fitness and the physical and psychological satisfaction of pursuing a challenging goal – are made more difficult because of a common punishment – injury.

Stress fractures, shin splints, plantar fasciitis – runners go to great lengths to avoid these obstacles that prevent them from pounding out their weekly miles. They search for the right shoe, the right stride and the right training routine.

In a study recently published in the Journal of the American Podiatric Medical Association, two UW Health researchers examined an affordable and easy method that may reduce impact force injuries common to distance running.

Katy O’Leary, a physical therapist at the UW Health Rehabilitation and Athletic Performance Clinic who specializes in athletic injuries, joined Bryan Heiderscheit, PhD, an associate professor in the University of Wisconsin School of Medicine and Public Health and director of UW Health Sports Medicine’s Runners Clinic, to examine the beneficial aspects of shock-absorbing insoles placed in running shoes.

While the results of the study stop short of guaranteeing a reduction in injury for runners, O’Leary and Heiderscheit did find that insoles significantly reduce impact forces associated with running.

The Study

Podiatrychannel.com, a health information Web site maintained by board-certified podiatry physicians, lauds running as great exercise but cautions about the toll it takes on the body.

Jogging, the Web site states, "generates forces equivalent to at least three times the body’s weight (with each step). It is important to do everything possible to protect the feet, ankles, knees, hips and lower back vertebrae."

To find if cushioned insoles provide such protection, O’Leary and Heiderscheit recruited 16 recreational runners from the Madison area. All were between 20 and 36 years old and screened to eliminate anyone with a recent history of lower-extremity injury.

"They had to run an average of 20 miles per week and couldn’t have any neurological or musculoskeletal impairments that wouldn’t allow them to run comfortably," O’Leary says about the selection process.

The subjects were given identical shoes and asked to perform 10 15-meter trials during which they ran at their own pace across a force plate, which measures a runner’s ground reaction force (the force projected back up through the body while running). To ensure the runners used their normal stride, they were not told to hit the force plate with their right foot, the foot from which O’Leary and Heiderscheit derived the data.

Accelerometers were attached to the subjects’ ankles to measure the amount of tibial acceleration that occurred while they ran. O’Leary and Heiderscheit were also careful to monitor the consistency of the subjects’ knee angles when their feet hit the force plate, because widely varying angles could have skewed the results.

Five of the trials were conducted with only shoes. For the remaining five, subjects used insoles, manufactured by the Ohio-based company Sorbothane. O’Leary and Heiderscheit both stressed that Sorbothane was not involved in any phase of the study, other than the insole donation.

"They were blind to everything until we sent them the final results paper," Heiderscheit said.

The Results

"We found a couple of good things," O’Leary says. "When the runners had the insoles in, there was a significant reduction in the ground reaction force at the initial contact point."

On average, the ground reaction force was nearly 7 percent less with the insoles. It may seem like a paltry number, but remember that’s 7 percent less force per step.

"When you think of a 7 percent reduction for, say, a 10-mile run, that’s a lot," Heiderscheit says.

Tibial acceleration also decreased, by 15.8 percent. Both factors are considered potential culprits for impact force injuries.

Ramifications

O’Leary and Heiderscheit emphasize the study results do not definitively prove that cushioned insoles reduce running injuries. That’s a much larger task and would require a more elaborate setup.

"We couldn’t come out and say it’s going to reduce injuries but it certainly has the potential to," Heiderscheit says. "The piece we’re missing is following these people over time. We’d have to account for their training differences."

Still, both are encouraged sufficiently to broach the subject with their patients.

"In my practice I’m willing to say, ‘Try it out,’ " O’Leary says. "If it’s uncomfortable, you’re probably not going to run normally. But if you have a pair of insoles that you’re comfortable with and you feel good about it, there’s a chance it might help reduce your risk. It’s something I’m willing to put out there."
And Heiderscheit believes the benefit of insoles is more likely to be reaped by casual runners rather than hard-core trainers who have their sights set on future marathons or Ironman competitions.

"If you’re putting in 10 to 12 miles per week, your body’s adaptation to those types of impacts will be much slower and you won’t have the same level of tissue strength as somebody who’s putting in 50 miles per week," he says.

Plus, the insoles could save money, because they protect not only the runner from impact force but insulate shoes from trauma, as well. With insoles at about $15 to $20 per pair, they’re a relative bargain compared with shoes that often cost $100 or more.

"Shoes are expensive but insoles are cheap," Heiderscheit says. "They can get you maybe an extra 200 miles out of your shoe."

 

Jogging/Running Frequency – The Balance Between Fitness And Risking Injury

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.

 

Preventing and Treating Running Injuries

By: Seamus Kennedy, BEng (Mech), CPed

Running has been referred to as the king of all workouts. It is an activity that has been embraced at varying levels of competence by nearly 11 million adults in the United States alone, according to the American Running Association. Running doesn't require the purchase or use of expensive equipment; it is possible to do it indoors or outdoors, usually year round. Not only does running provide a fantastic cardiovascular workout, it allows you to burn calories and clear your mind, leaving you with that relaxed, feel-good sense for many hours afterward. However, to reap these benefits on an ongoing basis, it is important to take precautions to prevent debilitating injuries.

For all the benefits of this great activity, there is no doubt that the repetitive nature of the stress it places on key joints can lead to breakdown. While there is some debate about what constitutes an injury, it has been estimated that up to 70 percent of runners will sustain some form of overuse injury during any one-year period. Anyone working in the orthotics, biomechanics, or sports medicine professions will see his or her fair share of running injuries. These injuries can be broadly classified as acute or chronic. Acute injuries are those due to sudden motions or twisting, such as an ankle sprain, which lead to soft tissue and/or osseous injury. These need to be treated immediately and allowed to heal.

Chronic injuries develop over time and are the result of repetitive stress that eventually leads to breakdown; e.g., patellofemoral syndrome. Chronic injuries account for well over 80 percent of running injuries, and they can develop from either an anatomical cause or a biomechanical issueand sometimes a combination of both. Because of its impact forces on the body, running greatly magnifies the extent of these anomalies. When experienced runners develop a chronic injury, it is often necessary to investigate what they have changed in their training practices.

To get a clear picture of any injury, it is necessary to do a full biomechanical exam. Evaluate the patient in stance and motion, non-weight bearing and weight bearing, in shoes and out of shoes. It is vital to follow the entire kinetic chainnot just treat the symptomto investigate the root cause of the problem. John Connors, DPM, a New York-based sports-medicine specialist, insists on watching his patients function in order to determine underlying causes. He will even run with his world-class patients in order to diagnose their etiology.

Common Running Injuries

Heel pain: Heel pain is a common complaint among runners. This is hardly surprising, given that the majority of runners who train on level ground at low to moderate speeds are heelstrikers. This running style produces an impact-force peak early in the stance phase, which can range from one-and-a-half to five times the runner's body weight. These impact forces are considered a primary cause of overuse injuries.

The classic sign of plantar fasciitis (PF) is heel pain that presents first thing in the morning and then decreases with activity. In the early stages, the patient usually can still exercise, only to be faced with more severe pain following a run. Typically, pain will be felt at the plantar-medial aspect of the calcaneus or at the middle aspect of the calcaneus.

There are other causes of heel pain that should not be ruled out without further radiographic examination. A calcaneal stress fracture may present like PF, but typically the pain does not subside as the day progresses. A positive calcaneal compression test can indicate the presence of such a fracture. Other considerations for heel pain include tarsal tunnel syndrome, neuritis of the first branch of the lateral plantar nerve, and tendinitis of the flexor hallucis longus.

Achilles tendinitis (AT): Achilles tendon injuries may be due to inflammation of the paratenon or the result of the degeneration of the tendon itself. It is broadly classified into two groups: insertional (occurring at the tendon/bone interface) and non-insertional (occurring proximal to its insertion, in or about the tendon proper). A physician's diagnosis will confirm the location and type of condition. AT can develop when the tendon contracts and tightens and is then over-stretched during exercise. There may also be a biomechanical component to the condition, given the tendon's broad insertion on the posterior calcaneus. Due to the cyclic rotation of the STJ from pronation through supination, there can be increased tension on the medial and lateral aspects of the tendon's insertion.

Iliotibial band syndrome (ITBS): This is a debilitating injury that presents as pain along the lateral aspect of the knee joint. It is sometimes accompanied by a clicking sensation. Current thinking is that ITBS results from weak core and hip muscles that fail to prevent tightening and strain the IT band.

Medial tibial stress syndrome (MTSS): Commonly known as "shin splints," this pain is typically noted along the lower third of the posterior medial surface of the tibia. It can often result from improper biomechanics or by not following the training considerations described earlier.

There are many other injuries that you are likely to see in runners such as posterior tibial tendon pain, knee pain, and a variety of stress fractures. Forefoot pathologies can include functional hallux limitus, sesamoiditis, and second metatarsal phalangeal joint (MPJ) capsulitis, in addition to regular blisters, corns, and neuromas. Much has been written on each of these conditions and their specific rehabilitation treatments. "How to Detect and Treat Running Injuries," by Brian Fullem, DPM, (Podiatry Today, May 2005) covers the basics. It is an excellent resource.

Preventative Measures

Over the years, I have developed a great love for running, so I can say from personal experience as well as patient interaction that nearly all running injuries result from training errors. I try to follow my own advice on injury prevention as outlined above. I begin a run by forcing myself to stretch; I change out my running shoes as necessary, even if they look almost new; and I vary my workouts with swimming, yoga, and sometimes bicycling to ensure adequate rest. I am pleased to say that I am injury free. However, when injuries do occur, treatment will generally follow a protocol of relieving pain, resting, icing, stretching, focused strengthening, and improving biomechanics. Good support from shoes and orthotics, good running form, and good training habits, such as always stretching, will prevent the return of many of these injuries. I believe foot orthotics, whether custom or not, play an essential role in keeping a runner injury free by aligning the body properly. Regardless of foot type, appropriate orthotics will increase shock absorption and prevent end-of-range-of motion, thus protecting tendons, muscles, and joints.

Another strategy for preventing running injuries is to advise your patients to modify their running style. Recently, I have begun using a technique called ChiRunning© ( www.chirunning.com). In essence, ChiRunning aims to lessen the forces that most runners experience by introducing a slight forward lean and a biomechanically efficient flow to their running style. It advocates running with relaxed lower legs and using a mid-foot strike to avoid the braking and impact of heel strike. Since adopting the ChiRunning approach, I have found running even more enjoyable, not to mention less strenuous.

Hopefully, armed with this information and more, you can help your runners achieve their goals.

Séamus Kennedy, BEng (Mech), CPed, is president and co-owner of Hersco Ortho Labs, New York, New York. He can be contacted via e-mail atseamus@hersco.com, or visitwww.hersco.com

Training Considerations

Increasing mileage and/or speed: Make any changes in distance or tempo gradually.

Breaking in new shoes: Break in new shoes slowly over a few runs. Ensure that the last and sole design match the runner's foot type; i.e., pronator, supinator, or normal/neutral.

Running in old or worn-out shoes: It is recommended that runners switch out their sneakers every 300-500 miles. If sneakers are over-worn, they lose shock absorption and their ability to control rearfoot and subtalar joint (STJ) motion.

Running on unforgiving surfaces: Elite runners usually avoid running on roads too often due to the unrelenting hard surface and the banked edges. It is best to look for firm trails with some forgiveness, such as dirt, woodchips, fields, or boardwalk. Slightly uneven terrain also helps avoid an exact repetition of each stride.

New running style: Any change in running technique should be applied slowly, to allow the body to adapt.

Be aware that a change in weight, and even aging, can contribute to the onset of an injury.

 

Preventing and Treating Common Running Injuries

Every runner's guide to preventing and treating 10 common pains and sprains.

By Denise Mann
WebMD Feature

Reviewed By Charlotte Grayson, MD

"Don't run and you'll heal," are the words that every diehard runner dreads hearing.

"Runners don't want to stop running, and the good news is that you can run through most pain without causing permanent damage," says Lewis G. Maharam, MD, medical director of the New York Road Runners Club, the New York City Marathon, NYC Triathlon, the Suzuki Rock 'n' Roll Marathon — among others. "But," he cautions, "if pain changes your running style, stop and see a sports doctor."

Most common running injuries are due to overuse, overtraining, or a biomechanical flaw in body structure and motion.

Here's how to prevent and treat the 10 most common running injuries so you never get sidelined again:

1. Runner's knee

Runner's knee is a wearing away of the back of the kneecap, causing pain in the knee. This can occur because of decreased strength of middle quadricep muscles, or shoes that do not give proper support when you come off of your forefoot on the inside. What to do? Maharam says the condition is typically treated with a full-length sports orthotic and strengthening exercises directed at the middle quad muscle. Talk to a sports medicine doctor about getting into physical therapy and learning about the best stretches to heal runner's knee.

2. Stress fractures

Stress fractures can be caused by overtraining, a shortage of calcium, or by some basic biomechanical flaw — either in your running style in or your body structure, says sports podiatrist Stephen Pribut, DPM, clinical assistant professor of surgery at the George Washington University Medical Center in Washington, D.C. Common stress fractures in runners occur in the tibia (the inner and larger bone of the leg below the knee), the femur (thigh bone) and in the sacrum (triangular bone at the base of the spine) and the metatarsal (toe) bones in the foot.

"The more the miles, the greater the stress," says Maharam. And this is one injury you should not ignore. "Stress fractures are like a hardboiled egg," he explains. "The shell is cracked and next stop is a full-fledged fracture." See a doctor who specializes in treating running injuries, Maharam advises. "We only tell runners to stop when they have a fracture or a stress fracture and then we put them in a pool for water-running because stopping exercise is unacceptable to (most) runners."

3. Iliotibial band syndrome, a.k.a. ITBS

Marked by a sharp, burning knee or hip pain, ITBS is a very common running injury among marathoners. Indeed, it's responsible for as many as 80% of all overuse pains on marathon day. The ITB is a ligament that runs along the outside of the thigh — from the top of the hip to the outside of the knee. It stabilizes the knee and hip during running, but when it thickens and rubs over the bone, the area can become inflamed or the band itself may become irritated — causing pain. "ITBS may be caused by running on a banked surface that causes the downhill leg to bend slightly inward and stretches the band, inadequate warm-up or cool-down, running excessive distances, increasing mileage too quickly or certain physical abnormalities," says Pribit.

The best stretch? Place the injured leg behind the good one. If the left side is sore, cross your left leg behind your right one. Then lean away from the injured side toward your right side. There should be a table or chair that you can hold onto for balance. Hold for 7 to 10 seconds and repeat on each side 7 to 10 times, prescribes Pribut. Anti-inflammatory drugs such as ibuprofen (some brand names are Motrin and Aleve) can help get the swelling down, he says.

4. Shin splints

The most common type of shin splints happen on the inside of legs. These medial shin splints are a running injury that results from a biomechanical flaw in your foot (which can be made worse by a shoe that doesn't offer enough support) and/or overtraining.

"Your best bet is to switch to a motion control or thicker shoe and a make sure to stretch out your calf muscles" before and after running, says Michael Fredericson, MD, doctor for the Stanford Cross Country and Track Team and an assistant professor of orthopaedic surgery at Stanford University School of Medicine. Do this by standing with your rear foot approximately two to three feet away from the wall. Your rear leg should be straight, the front leg bent and your hands touching the wall. Your feet should point ahead with heels on the ground. Hold for 10 seconds and repeat 10 times on each leg. Now do the same thing with your rear leg (that was straight) slightly bent at the knee. You should feel this stretch lower down.

5. Plantar fasciitis

Also known as pain in the middle of arch of the foot, plantar fasciitis is a running injury most frequently caused by an abnormal motion of the foot or too-tight calf muscles. Normally, while walking or during long-distance running, your foot will strike the ground on the heel, then roll forward toward your toes and inward to the arch, Maharam explains. "Your arch should only dip slightly during this motion but if it lowers too much, you have what is known as excessive pronation." What to do? "It is usually corrected with an orthotic and calf stretches" before and after running, Maharam says.

6. Achilles tendonitis

Achilles tendonitis is a running injury that typically occurs from abnormal foot stroke in push-off and too-tight calf muscles. "If you are pronating to the side and pulling at an improper angle, it becomes stressed and inflamed. That's why getting an orthotic to correct the biomechanics of your foot stroke at push-off is key," Maharam says. Also, he suggests doing the same stretch recommended for shin splints.

7. Muscle Pulls

Whether hamstring, quads, or any other muscle, pulls come from not being flexible and/or overexerting specific muscles. "Basically, pulls occur because you haven't stretched or because you are trying to beat your 18-year-old son in a sprint and you are 45," Maharam says. Pulls are basically small muscle tears, and the best way to treat a pull is to do more stretching before and after a run. To prevent hamstring pulls, place one leg on a chair and get your knee straight and bend over. Hold for 15-20 seconds. For an acute injury, ice and anti-inflammatory medication is helpful.

8. Ankle sprains

Ankle sprains occur because runners don't always watch where they are going. "They can step off curb or into pothole," Maharam says. "Pay attention to where you are running or run on a really good, level track where there is less chance of finding a gopher hole." When and if an injury does occur, ibuprofen and ice can help reduce swelling and pain.

9. Dizziness and nausea

"Most runner's drink too much, not too little" water, Maharam says. This can cause overhydration — also known as diluting — which lowers sodium levels in the body and stresses the kidneys. Common symptoms of diluting are nausea, vomiting, and dizziness. To avoid these problems, Maharam suggests: "Drink about one-cup (8 oz.) of fluid every 20 minutes while running. This way you will avoid becoming diluted."

10. Blisters

One of the most common sports injuries, blisters on the feet are usually caused by friction combined with excessive moisture. Avoid them by choosing synthetic socks — such as those by Nike Dryfit — that wick away moisture," Maharam says.

Remember, Pribut says, that "about 90% of running injuries are due to overtraining, so a very slow buildup is important, and so are rest days." You'll save yourself pain and reach your goals, Pribut says, if you "avoid the 'terrible toos' — training too much too soon, too often, and too fast."

 

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SOURCES: Lewis G. Maharam, MD, medical director, New York Road Runners Club, New York City Marathon, and NYC Triathlon. Michael Fredericson, MD, team physician, cross country and track team, Stanford University. Sports podiatrist Stephen Pribut, DPM, clinical assistant professor of surgery, George Washington University Medical Center, Washington, D.C.

To Stretch Or Not To Stretch

Author: Stan Reents, PharmD

If the average person was asked to define "fitness", he/she might point to the ability to run a distance race (ie., "aerobic fitness") or the ability to lift a large amount of weight (ie., "muscular strength"). But, flexibility is a component of fitness too, even though it may not get as much attention or respect as its siblings.

This brings us to the concept of stretching. Almost all athletes — from elite athletes down to the weekend warrior types — stretch. Thus, it seems intuitive that stretching prevents injuries….why else would everybody be doing it, right?

Indeed, recent studies have shown that stretching can influence the viscosity of the tendon and make it significantly more compliant. Thus, many believe that increasing the flexibility of a muscle-tendon unit promotes better performances and decreases the number of injuries. Because of this belief, stretching exercises are regularly included in warm-up and cooling-down exercises. However, the sports medicine literature is divided on whether stretching prevents injury.

But, before we get into the science, let's review some basics:

TYPES OF STRETCHING

To be precise, stretching can be classified into 5 different types:

• Ballistic Stretching: This is defined as: rapid lengthening (stretching) of a muscle by the use of jerking or bouncing movements, for example, bouncing down to touch your toes. This type of stretching is not recommended. In fact, it mimics the type of sudden stress that produces muscle injuries in the first place. Jerking a muscle into a full stretch causes it to lengthen beyond a safe stretch and may injure the muscle…exactly the opposite of what you are trying to achieve with stretching.

• Static Stretching: This type of stretching is characterized by a slow and sustained (eg., for 15-60 secs) lengthening of a muscle by the athlete without help from a partner. This is one of the best types of stretching because it does not pose the risk of injury to muscle and connective tissue as ballistic stretching does.

• Passive Stretching: Passive stretching is identical to static stretching, except that a partner is used to gradually move the arm or leg. The advantage of using a partner is that a greater range-of-motion can be achieved compared to stretching without a partner.

• Isometric Stretching: Isometric stretching is simply static stretching with the aid of an immovable object.

• Proprioceptive Neuromuscular Facilitation (PNF) Stretching: PNF stretching sounds more complicated than it really is. Technically, PNF stretching involves passive muscle lengthening with the use of a partner after an antagonistic muscle is contracted. PNF stretching is considered to be an excellent technic however the risk of injury is slightly greater than the other methods since the range of the stretch can be greater.

STRETCHING TO IMPROVE FLEXIBILITY

One of the benefits of stretching is that it does improve flexibility, albeit, short-term. Stretching, combined with warming up, has been shown to increase the flexibility of the ankle, hip, and knee joints (Thacker SB, et al. 2004). However, an improvement in flexibility does not automatically mean fewer injuries or improved athletic performance. This is where there is confusion in the literature.

STRETCHING AND MUSCLE PERFORMANCE

As mentioned above, while stretching does increase the flexibility of specific joints, greater flexibility, in turn, does not always lead to improved performance. After static stretching, the muscle-tendon unit is weaker for 10-15 minutes (or longer, see below). This phenomenon has been called the "stretch lag" period, or, "tendon slack".

In fact, in some cases, stretching actually worsens (measurements of) muscle performance. Stretching has been shown to impair maximal voluntary contraction force (Behm DG, et al. 2001), muscular endurance (Kokkonen J, et al. 2001), and one-repetition maximum (Kokkonen J, et al. 1998) when it occurs just prior to the performance assessment.

A study of 40 females using a vertical jump test to assess muscle performance revealed that adding PNF stretching to a general warm-up routine worsened jumping ability (Church JB, et al. 2001).

Another study shows the effect of stretching on muscular strength over time (Fowles JR, et al. 2000). Subjects performed 13 stretches of the plantar flexors, holding each stretch for 135 seconds during a period of 33 minutes. Maximal voluntary isometric contraction (MVIC) was assessed 6 times during the ensuing 60 minutes. MVIC was depressed as follows:

Time / Percent Strength Decrease

• Time 0: -28%
• 5 min: -21%
• 15 min: -13%
• 30 min: -12%
• 45 min: -10%
• 60 min: -9%

The authors concluded that an intense prolonged stretch (of the plantar flexors) reduces maximum voluntary force for up to 1 hour after stretching.

STRETCHING TO PREVENT INJURIES

Contradictory findings regarding the ability of stretching to prevent injuries have been reported in the literature. Stretching recommendations are clouded by misconceptions and conflicting research reports. Apparently, no scientifically based prescription for stretching exercises exists (Witvrouw E, et al. 2004).

One fundamental issue to consider is that, even though stretching improves flexibility, most injuries occur during an extremity's normal range of motion (ie., during eccentric contraction). Thus, it is illogical to conclude that improving flexibility will prevent most muscle injuries (Shrier I. 2000).

In 1999, Shrier reviewed the literature on stretching to prevent injuries. He found 12 papers with acceptable study design. Of those, 4 showed that stretching was beneficial, 3 showed that stretching was detrimental, and 5 showed no difference (Shrier I. 1999).

Australian researchers reviewed the literature in 2002 and found that stretching had no beneficial effect on delayed-onset muscle soreness (DOMS) and did not reduce the risk of injury (Herbert RD, et al. 2002).

A subsequent literature review, published in 2004 (Witvrouw E, et al. 2004), was much more revealing. These authors proposed a possible explanation for why there is disagreement on the issue of whether stretching prevents injury:

Witvrouw and colleagues believe that the type of sports activity in which an individual is participating needs to be considered. Sports that involve a lot of bouncing and jumping activities with a high intensity of stretch-shortening cycles (SSCs) (eg. basketball, football, soccer, tennis) require a muscle-tendon unit that is compliant enough to store and release the high amount of elastic energy that benefits performance in such sports. If the muscle-tendon unit is not compliant enough, the demands in energy absorption and release may rapidly exceed its capacity. This may lead to an increased risk for injury of this structure. Thus, when a sport demands stretch-shortening cycles (SSCs) of high intensity, such as jumping or abrupt changes in direction, stretching may be important for injury prevention.

In contrast, when the type of sports activity contains low-intensity, or limited SSCs (eg. cycling, jogging, swimming), there is no need for a very compliant muscle-tendon unit since most of the forces come from active muscle contraction to generate motion. Strong evidence exists that stretching has no beneficial effect on injury prevention in these sports.

In other words, whether or not stretching prevents injury depends on the type of activity being considered.

Witvrouw and colleagues believe that if this point of view is used when examining research concerning stretching to prevent injuries, the reasons for the contrasting findings in the literature are in many instances resolved.

USE OF STRETCHING TO HASTEN RECOVERY AFTER AN INJURY

While stretching to PREVENT an injury is not always helpful, the use of stretching to hasten recovery AFTER an injury has been shown to be beneficial:

• Hamstring Injuries: A Greek study randomized athletes with hamstring strains to light stretching (once per day) or a more vigorous program (4 times per day). The study was conducted from 1996-2001 and randomized 40 athletes into each of the 2 plans. All 80 athletes received RICE (rest, ice, compression, and elevation). The stretching involved static stretching for 30 seconds per stretch session.

The authors found that normal range-of-motion was achieved earlier in the 4 times per day group (5.6 days vs 7.3 days) and the time elapsed prior to achieving full athletic activity was also shorter in the 4 times per day group (13.3 days vs 15 days) compared to the once/daily group (Malliaropoulos N, et al. 2004.).

• Plantar Fasciitis: For plantar fasciitis, also known as "painful heel syndrome" or "proximal heel pain", stretching of the Achilles tendon has been shown to be beneficial in reducing pain, stiffness, and increasing range-of-motion (McNair PJ, et al. 1996; Porter D, et al. 2002). One study reported that a non-weight-bearing stretch of the plantar fascia was better than the classic standing Achilles tendon stretch (DiGiovanni BF, et al. 2003).

SUMMARY

Thus, while there still is some controversy regarding stretching to prevent injury, some conclusions can be offered:

• Stretching to PREVENT injury is most helpful in sports that involve sudden changes of direction, such as football, soccer, or tennis or sports that require lots of jumping such as basketball or volleyball. Stretching appears to be less helpful in sports that produce less shock to the muscles, such as cycling, jogging, or swimming.

• Do not stretch extensively (if at all) within 15-60 minutes prior to a competitive event.

• If you do stretch prior to a competitive event, work that muscle group for a few minutes to help the muscle(s) recover to their normal length and power capacity. For example, if you have just stretched your hamstrings and the front of your thighs to get ready for a race, do some light jogging for several minutes before the race begins.

• Avoid ballistic stretching: It is more likely to cause injury than other technics.

• Stretching injured muscles does appear to hasten recovery.

FOR MORE INFORMATION

A very succinct, yet thorough, review of the sports medicine literature on stretching was published in the Sept./Oct. 2002 issue of ACSM's Health and Fitness Journal (see Bracko MR, below). Although this publication is intended for sports medicine professionals, the article is written in an easy-to-understand style.

For a "how-to" book filled with diagrams, get the classic Stretching by Bob Anderson. Even though this book was originally published in 1980, it demonstrates every kind of stretch and stretching routine you can imagine.

REFERENCES

Behm DG, Button DC, Butt JC. Factors affecting force loss with prolonged stretching. Can J Appl Physiol 2001;26:261-272. Abstract

Bracko MR. Can stretching prior to exercise and sports improve performance and prevent injury? ACSM's Health and Fitness Journal 2002;6:17-22. (no abstract)

Church JB, Wiggins MS, Moode FM, et al. Effect of warm-up and flexibility treatments on vertical jump performance. J Strength Cond Res 2001;15:332-336. Abstract

DiGiovanni BF, Nawoczenski DA, Lintal ME, et al. Tissue-specific plantar fascia-stretching exercise enhances outcomes in patients with chronic heel pain. A prospective, randomized study. J Bone Joint Surg Am 2003;85-A:1270-1277. Abstract

Fowles JR, Sale DG, MacDougall JD. Reduced strength after passive stretch of the human plantar flexors. J Appl Physiol 2000;89:1179-1188. Abstract

Herbert RD, Gabriel M. Effects of stretching before and after exercising on muscle soreness and risk of injury: systematic review. BMJ 2002;325:468. Abstract

Kokkonen J, Nelson AG, Andrew C. Acute muscle stretching inhibits maximal strength performance. Res Quart Exerc Sport 1998;69:411-415. Abstract

Kokkonen J, Nelson AG, Arnall DA. Acute stretching inhibits strength endurance performance. Med Sci Sports Exerc 2001;33:11A. (no abstract)

Malliaropoulos N, Papalexandris S, Papalada A, et al. The role of stretching in rehabilitation of hamstring injuries: 80 athletes follow-up. Med Sci Sports Exerc 2004;36:756-759. Abstract

McNair PJ, Stanley SN. Effect of passive stretching and jogging on the series elastic muscle stiffness and range of motion of the ankle joint. Br J Sports Med 1996;30:313-317. Abstract

Porter D, Barrill E, Oneacre K, et al. The effects of duration and frequency of Achilles tendon stretching on dorsiflexion and outcome in painful heel syndrome: a randomized, blinded, control study. Foot Ankle Int 2002;23:619-624. Abstract

Shrier I. Stretching before exercise does not reduce the risk of local muscle injury: a critical review of the clinical and basic science literature. Clin J Sports Med 1999;9:221-227. Abstract

Shrier I. Stretching before exercise: an evidence based approach. Br J Sports Med 2000;34:324-325. Abstract

Thacker SB, Gilchrist J, Stroup DF, et al. The impact of stretching on sports injury risk: a systematic review of the literature. Med Sci Sports Exerc 2004;36:371-378. Abstract

Witvrouw E, Mahieu N, Danneels L, et al. Stretching and injury prevention: an obscure relationship. Sports Med 2004;34:443-449. Abstract

ABOUT THE AUTHOR

Stan Reents, PharmD, is a former healthcare professional. He holds Personal Trainer and Lifestyle Counselor certifications from the American Council on Exercise and has been certified as a tennis coach by USTA. He is the author of Sport and Exercise Pharmacology (published by Human Kinetics). 

 

5 Ways to Avoid Knee Injuries While Running

By Marrecca Fiore

 

Whether you're training for a marathon or enjoying a daily jog, running may be a good way to maintain good health. But it’s hard on the joints, especially the knees.

As many as 70 percent of runners may experience knee injuries at some point in their lives, according to Dr. Kevin Plancher, an orthopedic surgeon and sports medicine specialist.

And spring is one of the most common times of the year for running injuries to take hold.

“We see a lot of runners with injuries in the springtime and it’s not because they did anything wrong,” said Plancher, who owns Plancher Orthopedics and Sports Medicine with offices in New York City and Greenwich, Conn. “Runners get so excited once the warm weather hits that they go out and start running without stretching and without replacing their shoes from last year. And injuries can occur in runners whether they’re 20 or 40 or 60 years old.”

The most common knee injuries are patello-femoral pain, also known as runner’s knee, and iliotibial band (ITB) syndrome.

Runner's knee occurs when the kneecap (patella) rubs against the bottom of the thighbone, and can result in irritation and erosion of cartilage, Plancher said. ITB syndrome involves irritation to the band of tissue that runs along the outside of the thigh, which can become irritated from repetitive rubbing over the outside of the knee.

There are ways to prevent knee injuries, however.

“Just because you're a runner doesn't mean you'll have runner's knee — or any other knee injury," Plancher said. "These problems are typically caused by overuse or by a misalignment of the joint that's exacerbated by improper running habits — all things that can be avoided."

Here are some tips on how to prevent knee injuries:

1. Wear the right shoes. Forget cushioning for a second. First, runners need to find a shoe that fits their feet correctly. For example, some people have wide widths, others have more narrow widths. A doctor can help you find the right the fit for your foot.

 

Also, Plancher warns that even the most expensive pair of sneakers probably won’t provide runners with adequate support.

“A lot of running shoes nowadays have little support,” Plancher said, suggesting that users remove the inserts or insoles that come with their sneakers and buy new ones that offer better support.

“There are good inserts and bad inserts, it doesn’t really matter the brand,” he said. “The most important thing is to buy one that has a little rigidity to it. If you can bend it in half, it’s not going to offer you enough support.”

2. Always stretch. Stretching your muscles is necessary before any run whether long or short, fast or leisurely, Plancher said.

“Don’t underestimate the importance of stretching,” he said. “It’s the best way to get the blood flowing, especially in cool weather.”

In addition to knee injuries, stretching can also help runners prevent hip injuries, shin splints, and foot-cramping, Plancher said.

3. Cross train. Not surprisingly, runners tend to focus on one and only one method of exercise: running. Doing so tends to bring the body out of balance. In the case of runners, they tend to end up with hamstrings (the muscles the run along the back of the thigh) that are stronger than their quadriceps (which run along the front of the thighs.)

Plancher recommends runners add core-strengthening workouts to their routine that strengthen both the front and the backs of thighs, as well as the muscles of the hips and buttocks.

4. Don’t over do it. Once the warm weather hits, runners tend to immediately begin running long distances. Often, it’s a matter of taking on too much too soon. Plancher recommends starting out slowly and building your way back up to the longer runs you were doing last spring and summer.

For those who run year-round, overtraining can occur from running long distances too often without any breaks in between.

“Be sure to incorporate one or two days of rest each week, and mix a few easy or short runs in with the hard or long ones,” Plancher said. “Don't increase your mileage by more than 10 percent a week. Start at a slow pace and be sure to stretch before and afterwards, to keep your muscles limber and your joints flexible.”

5. Eat right, supplement wisely. Runners need to the right types of nutrients in order to maintain healthy joints. Experts recommend adults get 1,000-1,200 milligrams of calcium each day, Plancher said. Dark green vegetables and dairy products are the best sources of calcium.

Additionally, many runners take glucosamine and chondroitin sulfate supplements. Glucosamine is an amino sugar that seems to play a role in cartilage formation and repair, and chondroitin is a complex carbohydrate that helps cartilage retain water and maintain its elasticity. Plancher said some doctors even offer glucosamine shots to their patients.

Although the supplements don’t help everyone, some research has shown that taking the two together can provide relief for people with moderate-to-severe osteoarthritis pain. Plancher recommends a dosage of 1,500 mg per day of glucosamine and 1,200 mg a day of chondroitin sulfate.

 

 

Best products for marathon runners

 

By: Carol Bardelli

The Boston Marathon is the oldest and most prestigious marathon in the U.S. But about 800 marathons are run around the world every year. Marathon runners face unique issues and my picks for the best products for marathon runners are listed below.

Cherry Pharm

You may be asking why cherry? Have I got news for you. Research studies prove that a tart cherry juice blend like Cherry Pharm prevents the symptoms of muscle damage of intense exercise like marathon running. Cherry Pharm, the brainchild of John Davey, also has healthy benefits for non-athletes. Davey discovered fresh cherries and cherry juice relieves some forms of chronic pain. Developed in collaboration  with Cornell University and clinically tested at the Nicholas Institute of Sports Medicine and Athletic Trauma at Lenox Hill Hospital, Cherry Pharm retains maximum cherry phyto-nutrients. These phyto-nutrients are proven to lessen pain, reduce strength loss, and speed recovery in athletes and non-athletes alike. Now you really can drink to your health.

Fuel Belt

You know you need some way to carry your water and Cherry Pharm bottles on those long training runs. The Fuel Belt does just that. No more stashing bottles along your run route or carrying a bottle stuck in your fanny pack. The Fuel Belt solves your water issues with a comfortable elastic belt that firmly holds small bottles of water or any drink. The bottles don't bounce while you run and they carry as much water as an oversized bike bottle. The Fuel Belt is a comfortable and convenient solution to an age old runners' dilemma.

ArmPod

If you're like me having access to your music while you're exercising is a must. The new ArmPod music player holder straps onto your arm, is bounce-free, and a remarkably comfortable solution for carrying your MP3 player, mini disc, cell phone, and other must-haves. It custom fits to a full range of player sizes and shapes making it one of the most versatile armbands for your small electronics. And it provides full access to your player controls while you're on the run.

WIN High Performance Sport Detergent

WIN detergent's powerful and organic surfactants strip sweat, dirt, fungi, and grease from your filthy running clothes. It has a light pleasant scent and leaves your apparel soft and preserves the life of those favorite and often expensive pieces of clothing. WIN's oxy cleaning system was designed specifically for running enthusiasts but it's a valuable product for all athletes, weekend warriors, and fitness enthusiasts. This product truly is a WINner.

All of these products are available through online and mass market retailers including Amazon, WalMart, The Marathon Store, and The Sports Authority.
 

 

Jogging or cycling through middle age can delay aging by 12 years

 

Exercise: Cycling can hold back the years

By JENNY HOPE

Taking regular aerobic exercise could stop the biological clock and delay ageing by up to 12 years, claim researchers.

Keeping fit by jogging or cycling through middle age and beyond slows and even reverses the decline in muscle power, balance and co-ordination in later life.

Without regular workouts, maximum aerobic power falls in men by up to half between the ages of 20 and 60.

Women begin to lose fitness aged around 35, with aerobic power also falling by up to half by the age of 60.

 

Eventually, everyday activities become "intolerably fatiguing" for older men and women, says the study published in the British Journal of Sports Medicine.

But cardiovascular training – which strengthens the heart and lungs – would compensate for the onset of middle age, when the body's capacity to use oxygen and generate energy falls with each passing decade.

 And it has the added bonus of prolonging physical independence in old age, according to physical education experts at Toronto University.

They were exploring the idea, first put forward by them 20 years ago, that one of the most important factors influencing the quality of life in old people was the maintenance of sufficient "aerobic power".

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The latest study analysed existing research to discover how far the benefits of training last into old age.

It found that relatively high-intensity aerobic exercise over a relatively long period of time could boost maximal aerobic power by 25 per cent.

Dr Roy Shephard, of the university's faculty of physical education and health, said long-term aerobic training can maintain or restore aerobic power in later life.

The effect is the equivalent of turning back the biological clock for older people by up to 12 years, he added.

He said: "A regular exercise programme can slow or reverse the loss of aerobic fitness, reducing the individual's biological age and prolonging independence."

In the UK, most people do not exercise five times a week for 30 minutes or more – the Government's official recommendation for maximum health benefits.

The level of exertion should be enough to raise the heart rate to 120 beats a minute or higher, which includes a brisk walk and swimming.

But taking a stroll or even doing the gardening is also regarded as healthy activity.

A recent survey revealed at least one-quarter of men and women take no moderate or vigorous physical activity.

Other evidence shows regular activity cuts the risk of a range of health problems including diabetes, depression and heart disease. It also reduces the chances of premature death from any illness.

The Running Shoe Debate: How Barefoot Runners are Shaping the Shoe Industry

A group of running rebels are shedding their shoes and reporting years of injury-free miles. Some ultramarathoners, biomechanics experts and doctors think that’s probably a good thing. Others go so far as to say running shoes are in fact causing injuries. Meanwhile, running shoe companies continue to precisely measure runners, and pound and flex shoes in their high-tech labs. Could shoes—and shoe companies—be covering hundreds of thousands of perfectly able bare feet? If shoes are doing damage, just what are the companies measuring?

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