NEW YORK - Stretching relieves stiff muscles and can boost flexibility in the elderly and inactive but experts are divided on how vital it is for general fitness and preventing injury.
For older adults who lose flexibility through ageing, stretching can improve a range of motion and can make it easier to do everyday tasks such as reaching for items on high shelves.
Flexibility activities can also help reverse the chronically rounded shoulders and hands-on-keyboard posture of office workers tied to their desks.
But Dr. Mike Bracko, an exercise physiologist with the American College of Sports Medicine, said research indicates that static stretching, which involves holding a stretch for 30 to 60 seconds, does not reduce injury and actually makes the muscle weaker.
"I would say that flexibility in and of itself is not that important a component of general fitness," he said.
Bracko, a hockey skating coach based in Calgary, Alberta, notes that while activities such as gymnastics and rock climbing require flexibility, others, such as boot camp or cycling, do not.
"A lot of people just doing normal fitness activities don't need a lot of flexibility. It depends on the person," he said, adding that muscles tend to get injured within the normal range of motion.
"The classic example is how sprinters strain hamstrings: the leg reaches forward, at some point hamstrings have to contract fast. That's when the muscle fails," Bracko explained. "[Stretching] can't deal with that."
But he said some studies show that dynamic stretching, which unlike static stretching is not sustained and which mimics the activity to be performed, decreases the risk of injury by preparing the body for the movement to follow.
Stretch Zone Inc, which was founded in 2004 and has studios in New York, Florida and the Caribbean, specializes in practitioner-assisted stretches that are activity-specific and dynamic.
"Nothing is held for more than two seconds," said Miami-based founder Jorden Gold. "All the studies show little correlation between static, long-held stretches and sports performance."
The company includes stretches tailored to golfers, backpackers and officer workers, said Gold, whose clients range from the National Football League to musicians.
"With a sedentary lifestyle, the body picks up slack," he explained. "If, for example, I stretch hip flexors [which move muscles when running and walking], I'll feel lighter because the body is not fighting itself."
He said stretching can lengthen a muscle to 1.6 times its resting length.
But Jessica Matthews, a California-based exercise physiologist formerly with the American Council on Exercise, said the science on stretching is still evolving.
"We all agree on a dynamic warm-up," she said, "[but] research on stretching for injury prevention is still not conclusive enough to make that correlation. There isn't clear-cut evidence to support one thing or another."
The American College of Sports Medicine recommends adults engage in flexibility training a minimum of twice a week.
Matthews believes flexibility training is commonly the most neglected component of fitness.
"Flexibility will increase with flexibility training," she said. "How much is unknown." — Reuters
source: gmanetwork.com
