When to Stretch and When Not to Stretch

By: Dale J. Buchberger, PT, DC, CSCS, DACBSP

As the weather starts to improve many of us have thoughts of leaving the confines of the gym or basement to exercise outside. As this happens we will see many people stretching before they head out for a bike ride, for a run or before hitting that first golf ball. The question that is currently being debated is whether stretching should be performed before exercise. As usual there is no simple answer but a logical explanation. First, why do we stretch before exercise? The most reasonable answer is that we were taught to do this and this is what we know. We were told that stretching prepared and loosened us up before playing a variety of sports. As is customary today science is here to refute opinion and bring balance to the force. Lets see what the science has to say.

Recently, several studies have found that performing static stretching before participating in an activity such as running makes you slower and weaker. And when a group at the U.S. Centers for Disease Control and Prevention reviewed more than 100 studies of stretching, they found subjects who stretched before exercise were no less likely to suffer injuries such as a pulled muscle. In a study published in 2010 in the Clinical Journal of Sport Medicine, Roberto Meroni of the University of Milan and colleagues found people who stretched using conventional techniques, like bending over to touch their toes, were less flexible than those who did a more active or dynamic type of warm-up that required the use of several muscle groups.

Common stretching routines performed during warm-up procedures prior to exercise training or athletic competition have been found to increase flexibility for a short time, but there is little scientific evidence that this practice can improve exercise performance, reduce delayed-onset muscular soreness, or prevent injuries. Stretching just before exercise may actually cause temporary strength deficits or muscle weakness. Does this mean we should not stretch at all? The simple answer is no. The more accurate answer is that it is not whether you stretch, but when you stretch that is important.

The proper method of warm-up should not be to statically stretch a cold muscle or tendon. Warm-up procedures are submaximal activities that gradually and progressively increase the heart rate improving blood flow to the extremities. This process prepares the body for the more intense activity to come. My 15 year old son finds it astonishing that Jarret Eaton the NCAA indoor 60m hurdles champion spends 2-hours warming up for a 7.5 sec race. He has a lengthy warm-up process. Once warm he progresses to dynamic flexibility and then he is ready to begin actual sprinting and hurdling. Not everyone needs to take 2-hours to warm-up for a 3-mile jog. Some squats using an exercise ball, toe raises and lunges can be enough to warm-up for your jog.

When should you stretch? The best time to stretch is when you have completed your exercising for the day. Stretching on a regular basis, e.g., 3-5 days/week, away from the exercise environment may be effective in improving flexibility and some types of exercise performance. Most athletes recreational, collegiate or professional primarily stretch to improve deficits in range of motion. For instance if a baseball players’ shoulder has lost range of motion they would do a particular stretch after practice or games to gradually restore the required range of motion.

The current rule of thumb is to perform some type of dynamic warm-up prior to exercising. Things such as walking, skipping and jogging are good examples of warm-up procedures. Make sure that the warm-up activity gradually increases your heart rate and lasts at least 12-15 minutes. Your stretching routine should be designed around your deficit. If your Achilles tendon lacks range of motion you should focus on areas that would cause the tendon to become stiff. If you lack adequate hip range of motion to golf effectively you should focus on hip flexibility. Most stretching activities should be performed and held for 15-60 seconds per stretch. Keep in mind that stretching within 45 minutes of your activity may actually reduce your performance. Other studies have shown that regular stretching can reliably improve strength, jump height, and running speed.

Remember that warming up includes heart rate, blood flow, flexibility and neurological stimulation. Stretching alone does not equal a warm-up. A simple rule to follow is warm-up before you train and stretch after you train. This should help make your summer active and injury free.