Can strength training also improve your flexibility?
This article is verified by 2 studies/publications.
Lifting weights and becoming more flexible can sound like separate goals. Yet strength training may contribute to both. Moving a joint through a range of motion under resistance is more than a way to challenge the muscles: repeated training can also change how much movement you can achieve.
That is a useful possibility if you have limited training time. It does not mean every strength exercise improves every joint, or that stretching has become pointless.
Too long; didn’t read (Summary)
- Resistance training improved flexibility on average in a review of 36 studies with 1,469 analyzed participants.
- The programs lasted 4–24 weeks and studied healthy adults.
- Study quality and differences between programs limit confidence in what will work for you.
- The evidence does not establish that strength training can replace every stretching routine.
What researchers found
A review published online at the end of 2024 and in a 2025 journal issue analyzed 36 studies with 1,469 participants after dropouts. The studies involved healthy adults and compared resistance training with a control condition. Programs lasted 4–24 weeks. Flexibility was measured in several ways, including reach tests and joint-angle measurements.[1]
On average, resistance training improved flexibility relative to the controls. But the programs, participants and tests differed substantially, and none of the included studies was judged to have a low overall risk of bias. The range of effects expected in future studies also included no benefit. This supports a possibility of improvement, rather than a promise that any lifting program will make you more flexible.
Resistance training versus a control condition in healthy adults. The line shows the reported range of effects expected in a future comparable study, rather than the confidence interval for the average.
Flexibility after resistance training
A future study could find little or no benefit
Dot: the estimated average difference. Line: the range expected for the effect in a future comparable study.
The average favored resistance training, but the expected range for future studies includes no benefit. Programs and tests varied, and none of the included studies had a low overall risk of bias.
See the average and future-study range
| Outcome | Estimate | 95% prediction interval |
|---|---|---|
| Flexibility after resistance training | 0.6325 | -0.3463 … 1.6113 |
0 = no difference between the groups
Results, overall 36-study model: g = 0.6325; 95% PI -0.3463 to 1.6113; Discussion, first paragraph
Source: Favro et al., Journal of Strength and Conditioning Research (2025)
Does that make stretching unnecessary?
The 2025 review did not directly compare resistance training with stretching. A separate 2023 review did: its direct comparison included 7 studies and found no clear difference in improvements in joint range of motion. That result is not proof that the approaches are identical for every joint, person or goal.[2]
The studies also assessed flexibility, not whether participants were protected from injuries or ready to perform a demanding sport movement. You cannot turn an improvement in a reach test into evidence for those outcomes.
If you enjoy stretching, or need a particular movement range for your activity, these findings give you no reason to automatically remove it. They mainly challenge the assumption that strength training and flexibility must always be treated as unrelated tasks.
Watch the movement you want to improve
For your own training, think about the joints and movements that matter to you. A change at one joint does not tell you what happened elsewhere. Notice whether your actual movement range changes over time, rather than assuming that getting stronger automatically means becoming more flexible.
Use a controlled range you can manage in your strength exercises. Forcing an uncomfortable end position is not a requirement established by these reviews. If a specific flexibility goal remains unmet, targeted stretching may still have a place.
The practical takeaway is modest but useful: resistance training can contribute to flexibility, alongside its role in a strength program. The evidence supports combining goals where it works for you, while checking the result instead of expecting every method to do everything.
Sources
- The Influence of Resistance Training on Joint Flexibility in Healthy Adults: A Systematic Review, Meta-analysis, and Meta-regression. Favro F, Roma E, Gobbo S, Bullo V, Di Blasio A, Cugusi L, Bergamin M. J Strength Cond Res. 2025;39(3):386–397. doi: 10.1519/JSC.0000000000005000. Study.
- Resistance Training Induces Improvements in Range of Motion: A Systematic Review and Meta-Analysis. Alizadeh S, Daneshjoo A, Zahiri A, Hadjizadeh Anvar S, Goudini R, Hicks JP, Konrad A, Behm DG. Sports Med. 2023;53(3):707–722. doi: 10.1007/s40279-022-01804-x. Study.