It depends on how long you hold. Across 83 controlled studies, static stretching right before a strength test lowered maximal strength a little overall, a lot when each hold lasted 60 seconds or more, and not clearly when holds were shorter4. Jumping and sprinting were not hurt, and a normal warm-up after stretching may undo much of the loss.
What was studied
Two kinds of stretching matter here. Static stretching means holding a muscle in a long, stretched position without moving, usually for 15 to 60 seconds or more. Dynamic stretching means moving a joint back and forth through its range, like leg swings or arm circles.
The main paper is a 2024 meta-analysis, a study that pools many studies into one answer. Warneke and Lohmann included only controlled studies that measured people before and after stretching, which removed 120 studies that lacked a control or a before measurement4. That left 83 studies, 2,012 healthy participants and more than 400 effect sizes4.
Results are reported as an effect size: how big a change is compared with how much people normally differ. In this paper, under 0.2 counts as trivial, 0.2 to 0.49 small, 0.5 to 0.79 moderate and above 0.79 large4. A negative number means performance went down.
| What | Number |
|---|---|
| Controlled studies | 83 |
| Participants | 2,012 healthy people |
| Effect sizes pooled | more than 400 |
| Main outcome | maximal strength (the most force in one all-out effort) |
| Second outcome | jumping, sprinting, throwing |
| Average study quality | poor (3.95 of 10) |
In plain terms: this is the largest careful pooling of the question, but the studies inside it are often weak.
What the studies found
Maximal strength dropped a little on average. Compared with not stretching, static stretching lowered maximal strength by an effect size of −0.21 (95% confidence interval −0.39 to −0.02), a small effect4. A confidence interval is the range the true value most likely sits in.
Hold time made the difference. When each hold lasted 60 seconds or more, the loss was large: −0.84 (−1.32 to −0.37), from 8 studies4. When holds were under 60 seconds, the estimate was −0.13 (−0.32 to 0.07), which crosses zero, so no clear loss was shown4.
Jumps, sprints and throws were not hurt. For these athletic tasks, static stretching gave +0.13 (−0.08 to 0.35), not significant; in adults alone, jumping was slightly better (+0.15)4. An older 2013 meta-analysis did find a small drop in explosive performance (−2.0%), and advised against static stretching as the only warm-up activity1.
Dynamic stretching did not change strength. The estimate was +0.09 (−0.25 to 0.44)4.
Stretching right before a test, effect vs no stretching · effect size
An earlier review put these effects in percentages. It found about a 1–2% loss in strength and power when static stretching stayed at or under 60 seconds per muscle group, and about 4.0–7.5% when it went longer2.
Estimated strength and power loss by stretching time per muscle group · %
Low end of range High end of range
In plain terms: short holds cost little or nothing measurable; long holds cost real strength.
What it does and does not mean
The loss shows up most in lab strength tests. Many of the studies stretched one muscle, such as the calves or hamstrings, then tested that muscle alone on a machine4. The authors suggest this may be why strength fell in the lab while jumping and sprinting did not.
A warm-up after stretching may cancel it. The authors note that active warm-up routines done after stretching can counteract the strength loss, and that static stretching is rarely done in isolation in real training4. Their conclusion: they could not recommend stretching before performance, but "rigorous avoidance of any type of stretching before performance seems to be without evidence"4.
Stretching between sets is a different case. In one small study, 12 trained men stretched their quadriceps between sets of leg extensions. They lifted less total volume than without stretching, while stretching the opposing hamstrings did not lower it3. From the group means, that is about 22% less volume when the working muscle was stretched (our arithmetic).
This is about performance, not injury. None of the numbers here measured injuries. Stretching for flexibility or for growth are separate questions; stretching and muscle size are covered in does stretching build muscle.
In plain terms: a short stretch before lifting is unlikely to matter; long holds right before a heavy set, or stretching the working muscle between sets, can cost you reps.
What this looks like in practice
The studies that found no clear loss used holds under 60 seconds, and the authors note that warm-up activity done afterwards can counteract the loss that does appear42. So the setups with the least cost look like this: stretches kept short or dynamic, then the usual warm-up sets of the first lift. What those warm-up sets do is covered in does warming up help and how many warm-up sets before a heavy set. None of these studies tested stretching after the session, so they say nothing either way about when else to stretch.
The studies at a glance
| Study | Who was studied | Key result | Year |
|---|---|---|---|
| Simic, Sarabon, Markovic, *Scand J Med Sci Sports*1 | 104 studies of static stretching before exercise | Strength −5.4%, explosive performance −2.0% on average; smallest losses with stretches of 45 s or less | 2013 |
| Chaabene et al., *Front Physiol*2 | Review of studies in healthy people | Up to 60 s per muscle group: about 1–2% loss; longer: about 4.0–7.5% | 2019 |
| Pessoa et al., *Int J Exerc Sci*3 | 12 trained men; leg extension | Stretching the quadriceps between sets lowered total training volume | 2023 |
| Warneke & Lohmann, *J Sport Health Sci*4 | 83 controlled studies, 2,012 healthy people | Strength −0.21 overall; −0.84 with holds of 60 s or more; jumps and sprints not hurt | 2024 |
| Warneke et al., *J Sport Health Sci*5 | Panel of 20 stretching researchers | Consensus that stretching increases range of motion and lowers muscle stiffness | 2025 |
Limits worth knowing
- Weak studies inside a strong method. Average study quality scored 3.95 of 10 (poor), and the authors rated the certainty for strength as low4.
- Not every subgroup lined up. Some splits by total stretching time pointed in different directions, which is part of why certainty is low4.
- Single-muscle lab tests. Many studies tested one muscle on a machine, not a squat or bench press.
- Few long holds. The large −0.84 loss came from only 8 studies, all in adults4.
- Short-term only. All results are from the same session, not from months of training.
- Abstracts only for the 2013 review, the between-set study and the 2025 consensus.
Latest research
The newest paper we opened is a 2025 consensus statement from 20 stretching researchers, who reviewed the systematic reviews and needed 80% agreement to state a position5. They agreed that stretching increases range of motion and lowers muscle stiffness, and that stretch training does not add substantively to muscle growth or speed up recovery after exercise5. The abstract does not give a new number for strength right after stretching, so the 2024 meta-analysis remains the main source for this question.
The short version
- Static stretching right before a strength test lowered strength a little on average.
- Holds of 60 seconds or more lowered it a lot; holds under 60 seconds showed no clear loss.
- Jumping, sprinting and throwing were not hurt, and dynamic stretching did not change strength.
- Stretching the working muscle between sets lowered training volume in one small study.
Educational overview only — not medical advice.
