Should You Stretch When Warming Up?
What’s one of the most common things you see people do before working out? They stretch. Whether it’s a weight training session or a long run, many people naturally see stretching as something they should be doing. However, it’s possible that this common tactic could be sabotaging your results. In this article, I’ll break down what some of the research says about how stretching to warm up affects your performance, range of motion, and risk of injury.
Further, just to clarify, this article will only discuss the effects of stretching before exercise. This article will not be talking about the effects of following a stretching program or stretching after exercise.
Related: Warming Up Properly
How we are defining stretching
There are a few different ways that you can go about stretching. The form of stretching we will be talking about is static stretching, which is likely the form of stretching that you are familiar with. Static stretching involves pulling a muscle into a stretched position and holding it there for a period of time.
How stretching affects your performance
In terms of performance, we will be talking specifically about how stretching before training affects your strength and power. Strength being in terms of general weight lifting and power is regarding activities such as a vertical jump or a sprint.
This has become a rather widely studied subject in the research. What has been found is that there are significant decreases in both strength and power production after stretching. Further, the longer you hold the stretch, the greater the decrease tends to be. Overall, your muscles ability to produce force decreases after stretching.
This is obviously a major problem if you are stretching before a game or competition. However, it is also a major problem for your training as well. The decrease in training performance will compound over time and end up leaving you not as far progressed as you could be.
Why does stretching impair your performance? There are a few ideas that are talked about in the research, although there hasn’t been a clear, main culprit of them yet. One of the main reasons are that stretching reduces tendon stiffness, or in other words, the muscle is in a more “relaxed” state. Another of these reasons is that stretching causes partial damage to the muscle and partially fatigues it before you even start exercising. The last couple of hypotheses have to do with the idea that your nervous system is less able to send the signal for the muscle contract; and on top of that, the muscle itself is less able to conduct the electrical signal that produces a contraction.
How stretching affects range of motion
Many people’s justification for stretching before exercising is that they want to get “loose.” In this instance, being loose generally means increasing range of motion. So, no we have the question: does stretching actually help?
Well, stretching can improve your range of motion, but not in a very useful way. Stretching will increase your passive range of motion but not your active range of motion. I know that may be confusing, but allow me to explain.
You see, there is a difference between flexibility (passive range of motion) and mobility (active range of motion). Flexibility is really just how far you can stretch a muscle before it will start to tear under no load. Mobility, however, is how far a muscle can stretch while under load.
Let’s use an example to illustrate this. An example of working towards flexibility would be laying on the ground and reaching for your toes for 30 seconds. An example of working towards mobility would be taking a light weight and doing a stiff-leg deadlift as deep as you can for reps.
There is absolutely a time where trying to improve your passive range of motion makes sense. However, what is useful for exercise, and therefore more worth your time, is working to improve your active range of motion.
As a result, the bottom line is this: stretching provides no real, practical benefit to improving your range of motion before exercise.
How stretching affects your risk of injury
This is the last reason why someone might see stretching as something they should do before exercising. So, how does it hold up?
Overall, the research is rather mixed. Most of the studies show no difference in injury occurrence, some show increased number of injuries after stretching, and some show decreased. Based on the results you’ll find, it’s hard to draw any conclusion on how pre-exercise stretching affects risk of injury.
With results like these in the research it’s likely that there is a minimal, if any, effect on injury prevention from pre-exercise stretching. The studies that show a difference in injury occurrence likely had other variables in play that either promoted or reduced injury rate.
Conclusion
So, the bottom line on stretching in your warm ups is this. It impairs your performance, does not improve active range of motion, and seems to have no effect on risk of injury. Based on what the research says, it’s easy to say that stretching before you exercise probably doesn’t deserve the hype it has.
Reference
Acute effects of muscle stretching on physical performance, range of motion, and injury incidence in healthy active individuals: a systematic review
PubMed ID: 26642915
