The Study
Comparison of the effects of long-lasting static stretching and hypertrophy training on maximal strength, muscle thickness and flexibility in the plantar flexors
This study compares two different ways to make calf muscles stronger and bigger over six weeks. It shows that both stretching a lot and doing traditional exercises are linked to getting stronger and bigger muscles, but we can't be 100% sure one causes the other because the study wasn't perfectly set up to rule out other factors.
Analysis score
Maximum 72 for a cohort study.
Where the score came from
Researchers tested whether stretching your calves for an hour every day for six weeks builds strength and muscle size as effectively as traditional weight training.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 547 / 100
Quality score
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes, it proves that prolonged stretching can trigger muscle growth and strength gains, but it is highly impractical for most people due to the massive time investment compared to standard exercise.
- 2Both groups got stronger and their calf muscles grew similarly, but the stretching group spent 7 hours a week exercising while the weightlifting group only spent 45 minutes.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
European Journal of Applied Physiology
Year
2023
Authors
K. Warneke, K. Wirth, M. Keiner, L. Lohmann, M. Hillebrecht, Anna Brinkmann, Tim Wohlann, S. Schiemann
Related Content
Claims (5)
Doing one hour of static stretching every day for six weeks might make your calf muscles significantly stronger. In fact, the strength gains could be similar to those from traditional muscle-building workouts that only take 15 minutes three times a week.
Holding a stretch for a long time might build muscle and strength in your calves by triggering the same biological signals that weightlifting does. Researchers think this happens because the stretch creates tension that activates growth pathways in your muscles, though we haven't directly proven this in humans yet.
Doing static stretches for an hour every day for six weeks can actually build muscle in your calf, just as effectively as traditional weightlifting. This means that if you're looking to increase calf size, long stretching sessions might work just as well as lifting weights.
Spending an hour a day stretching your calves can make your ankles more flexible, giving you the same mobility benefits as doing heavy leg workouts for six weeks.
If you want bigger, stronger calves, lifting weights is much faster than just stretching. You only need about 45 minutes a week with weights to get the same results that would take over seven hours of stretching.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.