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Stretching Before Exercise Increase Joint Strength

Short-duration stretching before exercise temporarily improves range of joint motion and doesn't weaken muscles, says new research that fuels the debate about whether stretching before exercise reduces muscle strength and performance.

In this study, moderately active, non-athlete participants did two, four and eight-minute sessions of lower leg and ankle stretching. The participants' exercise performance was assessed before and immediately after, and also 10, 20 and 30 minutes after stretching.

The stretching didn't cause any changes in muscle strength, but did improve range of motion of the ankle joint. The findings were published in the August issue of Medicine & Science in Sports & Exercise.

"In moderately active individuals, short durations of stretching seem to temporarily improve flexibility without the detrimental strength losses that have been previously reported," study author Eric Ryan said in an American College of Sports Medicine news release.

"Pre-competition stretching became controversial due to what has been reported as decreases in performance, however, future research still needs to determine how these stretching exercises may impact athletes," Ryan said.

"Durations of stretching at or less than eight minutes may not significantly alter lower-leg strength," study co-author Joel T. Cramer said in the news release. "Our findings, in conjunction with previous studies, suggest that for these muscles, there may be a 'threshold' of stretching between eight and 10 minutes that would be necessary to decrease muscle strength."

Footnote:

Stretching used to be considered the main activity before a workout. That has all changed now. Stretching is still a beneficial activity prior to working out, but only after you have sufficiently warmed up. The reason for this is that stretching cold muscles can directly contribute to pulled and torn muscles. It's also now known that stretching is important after a workout as well.

Stretching properly may reduce muscle injuries and provides these benefits:

an increase in flexibility and joint range of motion
correct exercise posture
relaxed muscles
better sports coordination

What’s other experts suggesting :

According to professor of sports medicine at McGill University in Montreal; stretching before exercise does not reduce the risk of injury, according to one sports medicine expert. But, he says, stretching at other times may be beneficial. Moreover, "patients who have stiffness, for example a frozen shoulder, have to stretch to increase range of motion," he says. One of the greatest benefits associated with stretching is increased range of motion. "In this regard, it is true that in some specific sports stretching is necessary. A gymnast needs to stretch out in the splits, for example. Another example is a hurdler who needs to stretch out the muscles to clear the hurdles."
"Due to the paucity (small number), heterogeneity (dissimilar study subjects) and poor quality of the available studies no definitive conclusions can be drawn as to the value of stretching for reducing the risk of exercise-related injury." (The efficacy of stretching for prevention of exercise-related injury: a systematic review of the literature, 2003, Weldon)
A study published in the American Academy of Family Physicians (aafp) suggested that stretching before exercise does not decrease the likelihood of experiencing delayed muscle soreness. In young men, it also does not affect the rate of injury.
New research suggests that stretching doesn't prevent muscle soreness after exercise. Researchers Robert Herbert, Ph.D., and Marcos de Noronha, Ph.D. of the University of Sydney conducted a systematic review and meta-analysis of 10 previously published studies of stretching either before or after athletic activity. They concluded that stretching before exercise doesn't prevent post-exercise muscle soreness. They also found little support for the theory that stretching immediately before exercise can prevent either overuse or acute sports injuries.
The researchers, from the University of Sydney; British Medical Journal also could find no statistically significant protection from stretching before exercise against injuries like ankle sprains and muscle tears in two studies of army recruits.
Dr. Thomas Best, a sports medicine expert at the University of Wisconsin, says the Australian study is in synch with other research -- including his own experiments with animals showing that stretching doesn't strengthen muscles or tendons or make them more resilient.
Dr. Ian Shrier, a McGill University sports medicine specialist, says stretching before a workout may, in fact, make muscles more vulnerable to injury by tearing their fibers. What's more, despite popular perceptions, nearly all workout strains and pulls occur not when a muscle hits its limit of extension but when it is contracting -- so widening its range of motion has no theoretical reason for reducing the chances of harm.
According to physical therapist for Novacare and works at Medical Group Outpatient Rehabilitation in Michigan City, Indiana suggested that; while stretching can promote flexibility, stretching too far actually can damage the muscles—particularly if you’re recovering form an injury. "A healthy muscle can elongate up to 1.6 times its length," suggests Pitchford, "but generally doesn’t respond well to that much stretching." By overstretching, you create an automatic myotatic reflex that actually will cause the muscle to recoil to protect itself from tearing and injury. Also, don’t bounce while stretching. Holding your stretch in a static position works best.
According to David A. Lally, Ph.D., an exercise physiologist at the University of Hawaii-Manoa key finding - that stretching was associated with more injuries - was a shocker. After all, many runners believe that stretching has a protective effect, and a prior study carried out by Dutch researchers had indicated that although stretching might not lower injury frequency, it wouldn't lead to greater muscle mayhem, either.

Ref.:

http://www.ms-se.com
http://www.webmd.com
http://www.aafp.org
http://www.kidshealth.org
http://sportsmedicine.about.com
http://preventdisease.com
http://www.halhigdon.com
http://www.pponline.co.uk