Recently, there have been numerous articles reporting the effects of static stretching on strength. The studies were thorough and detailed the acute weakening effect of static stretching on the muscles. It doesn’t seem to matter if you stretch right before, or the day before, the acute weakening effect is significant and long-lasting even in experienced lifters. But with the health benefits of regular stretching, it seems reasonable to believe that in time this weakening effect must be reduced.
There is good reason to believe that chronic stretching would reduce the weakening effect on muscles. Perhaps the simplest way to explain this is that your reaction to exercise changes over time. Think about “beginner’s gains,” which are a perfect example of how a new program can shake up your results. Static stretching could well be the same way.
Static stretching simply means holding a stretch at the end of your range of motion. Once you feel the stretch you hold it there for a time. There are various kinds of static stretching. There are some kinds where you work the antagonist muscles (the muscles that do the opposite action of the one you are stretching) to create the stretch. There are other kinds where you work the muscle itself in its stretched position. And there are a number of kinds where you don’t work the muscles at all and only focus on the stretch. This study was concerned primarily with the latter, probably the most common of the static stretching varieties.
While we know the acute effects of static stretching on strength, what we need a better understanding of is the chronic effects. That is to say, we need to know what happens if we stretch and lift regularly, rather than just a handful of times in a laboratory setting that doesn’t really mimic what we do in the real world. A study this month in the Journal of Strength and Conditioning tackled this topic.
In the new study, the participants either performed strength training with stretching done before hand, strength training with stretching done during sets (the sort of thing you see all the time in the gym), and strength training alone. They compared the strength results and levels of IGF-1, a muscle building hormone, in each of the three groups after 10 weeks of training.
Much like the acute weakening effect, the researchers in this study found that static stretching also chronically weakened the muscles when performed both before and during exercise. That is to say, each group got stronger after 10 weeks. But the group that didn’t stretch at all got significantly stronger than the groups that did, and also had greater expression of IGF-1.
However, the researchers in this study acknowledged one major difference in the way that some people stretch. This is called “order of effect.” This study showed that stretching before or during exercise has a chronically weakening effect. Another study, which included a more substantial stretching element, suggested an increase in long-term strength resulting from stretching after exercise.
So if you like your static stretching like I do, fear not. While dynamic stretching (stretching through movement) is probably better pre-exercise, static stretching many well be the better choice for post-exercise. More research is needed, but for now, it’s a good bet.
References:
1. CL Borges Bastos, et. al., “Chronic Effect of Static Stretching on Strength Performance and Basal Serum IGF-1 Levels,” Journal of Strength and Conditioning Research, 27(9), 2013
2. J Kokkonen, et. al. “Early-Phase Resistance Training Strength Gains in Novice Lifters Are Enhanced by Doing Static Stretching” J Strength Cond Res 24(2), 2010
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