A new research paper from Florida State University may sound the death knell for static stretching before distance running events. In a question I asked her (see below), principal author Lynn Panton, Ph.D., says she and her colleagues have also concluded another, as-yet-unpublished article casting doubts on dynamic stretching.
The new paper, published in the Journal of Strength and Conditioning Research, looked at 10 highly fit male runners who were averaging at least 20 miles a week in their training. Before a treadmill test run, they either sat quietly for 16 minutes or did 16 minutes of static stretching exercises. They then ran for 60 minutes on the treadmill--the first 30 minutes at a relaxed pace, and the last 30 minutes as fast as they could.
With stretching, they covered an average of 5.8 km in the last 30 minutes. Without stretching, they ran 6.0 km, an increase of 200 meters or about 3.4 percent. Eight of the 10 runners performed better without stretching; one performed better with stretching; and one performed essentially the same under both conditions. On average, the stretchers hit a max heart rate 5 beats per minute higher than the non-stretchers in the final 30 minutes. In other words, the stretchers were working harder but covering less distance.
In another interesting comparison, Panton and colleagues measured the calorie-burn of the runners during the first "easy" 30 minutes of the treadmill test. In this case, the stretchers burned more calories than the non-stretchers. In other words, the stretching routine seemed to make them less efficient.
The presumed benefits of stretching are so ingrained in runners and other athletes that it's difficult to help them understand why stretching might be counter-productive, at least as a pre-race routine. Here's what the Panton paper says: Increased flexibility might lead to "lower muscle-tendon stiffness and strength," while "high muscle strength and muscle-tendon stiffness are more efficient." If stretching increases flexibility and decreases muscle-tendon stiffness, then "it may increase energy consumption during an endurance event, decreasing the performance of trained athletes."
This leads inevitably to the study's conclusion: "Stretching before an endurance event may lower endurance performance and increase the energy cost of running." If you shouldn't stretch, what should you do? Most studies still support a sufficient warm up. The warm up should probably include short pickups at a speed roughly equivalent to the speed you expect to run during the race. These pickups will prime your muscles without fatiguing them.
Panton and colleagues draw no conclusions about possible relationships between stretching and injury prevention. They have only been studying performance, and only with well-trained athletes. The stretching and injury-prevention question remains difficult to resolve, although there are few studies indicating that stretching is effective.
Here, researcher Lynn Panton, Ph.D., answers several questions about the new research.
Q: What do you think is the major contribution of your new paper?
A: Of course, our subjects were specifically a group of well-trained distance runners. Most of the previous studies were with power athletes. I think our study follows along with results that have been published with strength performance and sprint performance that stretching before the actual event may hamper performance at the elite level. We're talking about situations where a second or less can make the difference between 1st and 2nd place. For the recreational runner, I don't think stretching is going to have a huge impact.
Q: So you don't recommend stretching before racing? What about improving one's range of motion?
A: Again for the recreational runner I don't think stretching is going to make a huge impact. Stretching is very important though for health benefits. The best time to stretch is after you have exercised. That's when you are going to improve your range of motion the most. We know that individuals who stretch have better ROM and have less problems with back pain. So it's still important to stretch but concentrate on stretching during your cooldown.
Q: Any thoughts on dynamic stretching as opposed to static stretching?
A: We actually have a article in review on dynamic stretching. Although the differences were not significant in performance between the strecting and nonstretching group, there were still decrements that could have implications for the elite athlete when 1st and 2nd place can be determined by tenths of a second.
Q: Are you doing any other followup studies on stretching for runners?
A: We also have a women's study in review too. We did not see the differences in the women, so I am not sure what to think. Maybe women are more flexible in general, or perhaps our sample women runners were not as elite as our men. But we saw no differences in performance between the stretched and nonstretched groups.Tags: Columns