Resistance Training Boosts Flexibility: Understanding Recent Research
Key insights: 60-second read
- Resistance training improves flexibility – A 2025 systematic review shows lifting weights produces significant gains in joint flexibility, comparable to stretching.
- High intensity is key – Heavier loads led to greater flexibility improvements than low-intensity training with lighter weights.
- Two-for-one benefit – You get large gains in muscle strength alongside improved mobility, making resistance training time-efficient.
- Full range of motion matters – Exercises like deep squats and overhead presses performed through complete ranges build functional flexibility.
If you think improving your flexibility is all about static stretching, it's time to rethink your routine. Groundbreaking research now reveals a powerful, time-efficient ally: resistance training.
A major 2025 systematic review and meta-analysis published in the Journal of Strength and Conditioning Research has concluded that resistance training isn't just for building muscle - it's also highly effective at improving joint flexibility in healthy adults.
This is a game-changer for anyone who wants to maximise their training time or finds traditional stretching boring or ineffective.
On this page
1. What the Research Discovered
The researchers analysed 36 high-quality studies involving nearly 1,500 healthy adults. The results were clear: participants who engaged in resistance training saw significant improvements in their joint flexibility compared to those who did not. (1)
The overall effect was a medium-to-large improvement, proving that lifting weights can indeed help you move more freely.
Here are the key takeaways that can influence how you design your workouts:
- Intensity Matters: The study found that high-intensity resistance training led to significantly greater flexibility gains than low-intensity training. This means challenging your muscles with heavier loads is more beneficial for your range of motion than using light weights for many reps.
- It Works for Everyone: The positive effects on flexibility were seen across different age groups and activity levels. Whether you're a dedicated athlete or new to exercise, incorporating resistance work can help.
- A Powerful Side Effect: As you might expect, the research also confirmed that these training programs produced very large improvements in muscle strength. This means you get a powerful two-for-one benefit from your efforts.
2. Why Would Lifting Weights Improve Flexibility?
It may seem counterintuitive. Won't building muscle make you "tight"? The science suggests the opposite. Here's why resistance training is so effective, from a physiotherapy perspective:
- Improved Neuromuscular Control: Resistance training enhances the coordination between your muscles. It teaches your agonist (prime mover) and antagonist (opposing) muscles to work together more efficiently. This allows for smoother, more controlled movements through a greater range of motion.
- Increased Stretch Tolerance: Like stretching, resistance training can gently increase your tolerance to the sensation of stretch, allowing your joints to safely move further.
- Training Through Full Ranges of Motion: When exercises like squats, bench presses, or lunges are performed through their full, natural range of motion, they actively strengthen your muscles in their lengthened positions. This is key to building functional flexibility, not just passive range.
3. A Note on the Science: Limitations and Generalisability
As with all research, it's important to understand the context of these interesting findings.
- Limitations: The authors noted a "substantial amount of heterogeneity" between the studies. This means the training programs, flexibility tests, and participant populations were quite diverse, making it difficult to pinpoint one perfect "recipe" for flexibility. Additionally, the overall risk of bias in the included studies was a concern, which is common in exercise science, where fully "blinding" participants is difficult.
- Generalisability: The great news is that this research was conducted exclusively on healthy adults. This means the findings are directly applicable to the general population looking to improve their fitness. However, the results should not be automatically applied to individuals with specific injuries, hypermobility syndromes, or those in acute rehabilitation without guidance from a physiotherapist or health professional.
4. How to Apply This To Your Routine
Ready to build a stronger, more flexible body? Here are some practical tips based on the research:
- Focus on Full Range: Prioritise exercises that take your joints through their complete range of motion. Think deep squats, overhead presses, and chest presses where you lower the weight fully. Technique is key here. If you try to go beyond your current available range, your body may compensate to go around things. Just work to your current technical depth and know that your depth will improve as your range improves.
- Embrace Intensity: Don't be afraid to lift heavy (with good form, of course!). The study suggests that higher intensity is a key driver for flexibility gains.
- No Need to Abandon Stretching: This research isn't saying to stop stretching altogether. A combination of resistance training and targeted stretching is likely the most comprehensive approach for optimal joint health and performance.
The Bottom Line from Your Physio
This research powerfully demonstrates that resistance training is a viable and effective strategy for improving joint flexibility. It offers a time-efficient way to build strength and mobility simultaneously, breaking the old paradigm that you must choose one or the other.
If you are looking to create a safe and effective program that combines strength and flexibility for your specific needs, I am here to help.
I genuinely hope this article offers a fresh perspective - or at least one useful takeaway. If you have a different issue, or simply want to learn more about how your body moves, head over to the Your Wellness Nerd YouTube channel. Subscribe if you feel inclined, and let me know in the comments what you'd like me to cover next.
– Grant
Frequently Asked Questions
Does lifting weights make you less flexible?
No, the research suggests the opposite. A 2025 systematic review found that resistance training significantly improves joint flexibility, especially when performed with high intensity and through full ranges of motion.
Should I stretch or lift weights for flexibility?
A combination of both is likely most effective. Resistance training builds strength while improving range of motion, and targeted stretching can address specific tight areas. The research shows resistance training alone produces significant flexibility gains.
What exercises are best for improving flexibility with weights?
Exercises that take joints through their full range of motion are ideal. Deep squats, overhead presses, lunges, and bench presses where you lower the weight fully all help build strength in lengthened positions, promoting functional flexibility.
How heavy should I lift to improve flexibility?
The research found that high-intensity resistance training (heavier loads) led to significantly greater flexibility gains than low-intensity training. Focus on lifting challenging weights with good form, rather than light weights for high repetitions.
One profound insight from this post
"High-intensity resistance training produces greater flexibility gains than low-intensity training. You don't need to choose between strength and mobility - lifting heavy through full ranges of motion delivers both."
References:
(1) Favro, F., et al. (2025). The Influence of Resistance Training on Joint Flexibility in Healthy Adults: A Systematic Review, Meta-analysis, and Meta-regression. Journal of Strength and Conditioning Research, 39(3), 386–397.
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Source: Favro, F., et al. (2025). The Influence of Resistance Training on Joint Flexibility in Healthy Adults: A Systematic Review, Meta-analysis, and Meta-regression. Journal of Strength and Conditioning Research, 39(3), 386–397.
