PoshanSenseShould you stretch before a workout—or warm up first?
Static stretching, dynamic movement and warming up are different. A small sprint trial explains why “never stretch before exercise” is too simple.
Complementary human studies · Published 2016, 2017
You arrive at the gym or running track and face two familiar instructions: stretch so you do not get injured, and never stretch because it will make you weaker. Both sound confident. Neither captures the whole question.
What are you trying to prepare for?
A slow flexibility session, a sprint, a lifting session and a casual walk do not ask the same thing of your body. “Stretching” also describes different actions: holding a position is static stretching; moving repeatedly through a range is dynamic movement.
A warm-up is the broader preparation before an activity. It may include movement and stretches, but its purpose is not simply to reach further. Treating a few held positions as the whole warm-up—or treating every stretch as harmful—loses that distinction.
The wider evidence puts duration in context
A 2016 systematic review found that longer held stretches tended to impair immediate performance more than shorter holds. Most tests happened soon after stretching; studies that followed stretches with dynamic activity did not show a clear performance penalty. This is context, not a stopwatch rule for every person. The review found no clear overall reduction in all-cause or overuse injuries from static or PNF stretching, and no injury data for dynamic stretching. Its studies varied substantially and focused on healthy active people, excluding older-adult studies.
The study is a useful challenge to a blanket rule
In the 2017 Portuguese experiment, athletes ran after three different preparations. There was no clear difference in the first sprint. In the second sprint, the static-stretch condition was faster than the running-only condition. Differences involving the dynamic condition were less clear.
That does not mean static stretching is always best. Sixteen people and two short sprint tests cannot settle every sport. It does show why “static stretching always ruins performance” goes further than this evidence permits.
The detail that often disappears from a headline is context: stretching followed a running warm-up, and participants then rested before sprinting. The stretching conditions also took longer than running alone. Researchers could not separate the type of stretch from every other difference in the preparation.
What does this tell us about injury prevention?
Very little directly. The experiment measured sprint performance and physiological responses, not injuries over a season. A preparation that helps a particular sprint result has not thereby been shown to prevent a pulled muscle.
The same boundary applies to soreness, flexibility and long-term strength. Those require their own outcomes and follow-up. It is reasonable to discuss them as separate questions; it is not reasonable to award all those benefits to a routine because it improved one timed effort.
Preparation is more than one stretching label
Warm-up
The overall preparation for the activity that follows.
Static stretch
A held position; effects depend on context and dose.
Dynamic movement
Repeated movement; not an automatic injury guarantee.
Outcome matters
A sprint result does not establish injury prevention.
A more useful way to think about the choice
First distinguish preparation for today's activity from a separate flexibility goal. Then consider what the activity actually involves: repeated steps, quick direction changes, a large range of motion or controlled resistance. A sports coach or physiotherapist can help match preparation to those demands, especially if pain or a previous injury changes the situation.
This is not a prescribed routine. The experiment used young athletes accustomed to sport, so copying its stretches and timings is not an evidence-based plan for a beginner, an older adult or someone rehabilitating an injury.
It also offers no reason to force a stretch through pain or to chase a greater range simply because a warm-up is meant to feel productive. The study compared defined conditions, not an escalating test of discomfort.
What is the answer to take away?
Warm up for what you are about to do. Stretching may be one part of that preparation, but the research does not support one rule that fits every workout. If someone says static stretching is always bad or dynamic stretching always prevents injury, ask which outcome, which routine and which people the claim concerns.
The trial reported Portuguese FCT and European regional funding and no conflicts of interest. Its small size remains a limitation regardless of who funded it. Educational article; not clinically reviewed.
Sources & further reading
- Portuguese warm-up crossover experiment (2017)
- Broader systematic review of stretching and performance (2016)
Study years differ from this article’s publication date. We reviewed full primary papers and relevant supporting material; access limitations are kept out of efficacy claims. Original illustrations and diagrams; no publisher figures reproduced. Educational writing, not clinical review.
Published 11 October 2026 · Sources checked 11 October 2026. Suggest a correction.