For as long as you can remember, stretching before exercise has been a part of a healthy fitness routine. Personal trainers and phys ed coaches pounded into your brain the importance of stretching prior to your workout. However, a controversial new study has caused many to rethink some long-held notions about stretching.
In an Australian study published in the February issue of Medicine and Science in Sports and Exercise, researchers investigated the affect of muscle stretching during warm-ups on the risk of exercise-related injury among a study group of more than 1,500 army recruits. Each recruit was randomly selected and assigned to a stretch or control group. In 12 weeks of training, both groups were made to perform warm-up exercises before physical-training sessions. However, the stretch group performed a 20 second static stretch for each of the six major muscle groups during their warm-up routines. The control group did no stretching at all.
Over the course of the study, 333 leg injuries occurred among all recruits. Of these injuries, 158 injuries were reported in the group that performed stretches while 175 injuries were documented in the group that performed no stretches. Researchers of this study concluded that stretching before exercise does not reduce the risk of exercise-related injury.
Before you toss out stretching prior to your exercise routine, eFit’s resident exercise physiologist, Nancy Yumkas, cautions that the fitness level of army recruits is far beyond that of the average person exercising at your local gym. Every time you contract a muscle (for example, a bicep curl), it shortens. A buildup of lactic acid occurs in the muscle, which causes muscle soreness. Stretching will break up the lactic acid, elongate the muscle and prevent soreness the day after working out. “I would not generalize such a huge component of fitness on healthy, athletic men,” says Yumkas. Recruits, she says, work out daily, therefore their muscles are constantly warm and loose. The average person doesn’t work out as frequently and is more likely to have tight muscles, which can lead to injuries. For example, she says, marathon runners can stretch less frequently because their muscles are much warmer from the frequent and constant repetitive movement than the average person’s muscles. “The muscles are less flexible when cold and are more likely to be injured in this state,” says Yumkas.
Conversely, if you are already injured, a protective mechanism that creates fluid in the injured area can subsequently limit your mobility, so you must stretch regularly to break up that fluid to prevent tightness and muscle guarding. For those who do not have an injury but their muscles, such as their hamstrings, are naturally tight, Yumkas warns against skipping pre-exercise stretches. “Stretching before your routine will prevent you from getting even tighter and possibly cause future injuries, such as hamstring strains or pulls, herniated disks and tight IT bands known as runner’s knee,” says Yumkas. Stretching is a component of fitness and injury prevention.
You should never stretch cold, tight muscles, says Yumkas. By doing so you are setting yourself up for injury. A healthy stretch routine follows a five- to seven-minute warm-up such as walking or using a stationary bike. When you’ve completed your warm-up, try to focus on the areas that you will be exercising the most. For example, if you are strength training, pay attention to your chest, back, arms and major leg muscles. If running is your sport, key your stretches on your hamstrings, glutes, quadriceps and calves.
Most important, says Yumkas, each person has different needs and levels of flexibility. It’s unfair to base the study on healthy athletic recruits when the majority of exercisers have not reached the same level of fitness. Nonetheless, you should always consult your physician before you start any exercise routine.