Should You Stretch? What Stretching Does and Doesn't Do

Almost everyone has been told to stretch. Stretch before you run so you don't pull something. Stretch after so you aren't sore tomorrow. Stretch your hamstrings because they're tight and that's why your back hurts. The advice is so common that it rarely gets questioned.

The research on stretching has been accumulating for over twenty years, and the picture it paints is more modest than the folklore. Stretching does some things well. It does other things poorly or not at all. Knowing the difference saves you time and points you toward what actually matters for your goal.

What stretching does well

If your goal is to move further into a position, stretching works. Regular static stretching reliably increases range of motion at the joint you're stretching. If you need deeper hip flexion for a sport, a wider straddle for gymnastics, or more shoulder reach for swimming, stretching is a reasonable tool.

What's interesting is how it works. For the first several weeks, the muscle itself doesn't appear to get longer. Instead, your nervous system becomes more tolerant of the stretch sensation, so you can go further before it feels like you've reached the end.¹ The tissue hasn't changed much; your tolerance has. Longer-term, consistent stretching may produce some structural change, but the early gains are largely about the brain letting you go there.

This matters because it reframes "tightness." Often a muscle that feels tight isn't short. It may be guarding, fatigued, weak, or simply unaccustomed to the position you're asking of it. Stretching can change how it feels, but it may not fix the reason it felt that way.

What stretching doesn't do

Three common claims don't hold up well.

Preventing soreness. A systematic review in the BMJ pooled the trials on stretching before or after exercise and found it reduced next-day soreness by a trivial amount, roughly a point or two on a 100-point scale.² If you're sore after a hard session, that soreness is a normal adaptation response. Stretching won't meaningfully prevent it, and it doesn't need preventing.

Preventing injury. The same review found no meaningful reduction in injury risk from stretching before exercise.² Larger reviews since have reached the same conclusion: stretching on its own doesn't protect against injury, while strength training does, reducing sports injuries by roughly a third and overuse injuries by nearly half.³ If you have ten minutes before practice and have to choose, a dynamic warm-up and some strength work earn their place more than a hamstring hold does. We've covered what a good dynamic warm-up looks like, and why strength training is the most protective thing most athletes aren't doing enough of.

Improving performance. Long static holds right before explosive activity can slightly reduce strength and power for a short window afterward. The effect is small and mostly shows up with holds over 60 seconds, so it's not something a recreational athlete needs to lose sleep over.⁴ But it does mean that a pre-game stretch routine isn't making you faster or stronger, and the dynamic alternatives are a better use of the time.

Why the "tight muscle" story is usually incomplete

A lot of stretching happens because something hurts and the muscle nearby feels tight. Hamstrings get stretched for back pain. Calves get stretched for Achilles pain. Hip flexors get stretched for almost everything.

Sometimes that helps in the short term, because stretching changes sensation and sensation is part of pain. But if the underlying issue is a tendon that can't handle the load being asked of it, or a hip that's weak and letting the knee drift, stretching the painful region is treating a symptom. The tissue didn't become painful because it was short. It became painful because the demand exceeded what it was prepared for. There are no bad exercises, only too much too soon,⁵ and the fix is usually to build capacity, not to pull harder on the sore part.

This is also why we tend to assess movement as a whole rather than one muscle at a time. A hamstring that feels tight on one side often sits downstream of how the pelvis or hip is working, and a stretch alone won't change that.

So, should you stretch?

A reasonable set of rules:

• If you need more range for your sport or daily life, stretch the specific positions regularly. Expect gains over weeks, not days, and keep it up or they fade.
• If you're stretching to prevent soreness or injury, redirect that time toward a dynamic warm-up and progressive strength work.
• If you're stretching because something hurts, it's fine as a comfort tool, but treat it as a signal to look at load and strength rather than as the whole plan.
• If stretching simply feels good and helps you wind down, that's a legitimate reason. Not everything needs a performance justification.

None of this makes stretching bad. It makes it a tool with a specific job. When patients come to us with a long stretching routine that hasn't moved their pain, we don't tell them to stop. We work out what the routine was trying to accomplish and whether something else does it better. That's the same approach we take across the services we offer: match the tool to the problem, and be willing to say when the tool isn't the right one.

The research on stretching is a nice reminder that being common isn't the same as being effective. Stretch for range when you need range. For almost everything else, get stronger first.

References

1. Weppler CH, Magnusson SP. Increasing muscle extensibility: a matter of increasing length or modifying sensation? Phys Ther. 2010;90(3):438-449.
2. Herbert RD, Gabriel M. Effects of stretching before and after exercising on muscle soreness and risk of injury: systematic review. BMJ. 2002;325(7362):468.
3. Lauersen JB, Bertelsen DM, Andersen LB. The effectiveness of exercise interventions to prevent sports injuries: a systematic review and meta-analysis of randomised controlled trials. Br J Sports Med. 2014;48(11):871-877.
4. Behm DG, Blazevich AJ, Kay AD, McHugh M. Acute effects of muscle stretching on physical performance, range of motion, and injury incidence in healthy active individuals: a systematic review. Appl Physiol Nutr Metab. 2016;41(1):1-11.
5. Gabbett TJ. The training-injury prevention paradox: should athletes be training smarter and harder? Br J Sports Med. 2016;50(5):273-280.