Study finds stretching can build muscle like weight training – what that means for your workouts

If you tend to skip your stretches or cut reps short before reaching a full range of motion, new research on ‘stretch-mediated hypertrophy’ might make you rethink your training – particularly if building muscle is one of your goals.

Published in the European Journal of Applied Physiology, the study compared a stretching protocol with traditional strength training and found that participants in the stretching group developed similar increases in muscle thickness to those following a lifting routine.

Before you start holding long hamstring stretches in the hope of bigger biceps, though, it’s worth taking a closer look at the research to see what the findings actually mean.

The study involved 81 physically active participants with prior training experience, divided into three groups:

Group 1: Static stretching group
Group 2: Resistance training group
Group 3: Control group (no exercise protocol)

The stretching group performed 15 minutes of pectoralis major (chest muscle) stretching four days per week over eight weeks. Participants used equipment such as a pec deck machine to maintain the stretch for the full duration and were supervised to ensure the stretch intensity remained high.

The resistance training group followed a traditional chest-focused strength programme three days per week for the same eight-week period.

Researchers measured:

• Maximal isometric strength
• Muscle thickness using ultrasound imaging
• Shoulder range of motion (ROM)

The results showed significant improvements in strength, muscle thickness and flexibility in both the stretching and resistance training groups.

Interestingly, there was no significant difference between the two groups in terms of muscle growth or strength gains. The stretching group also saw greater improvements in flexibility compared with the lifting group.

However, researchers emphasised that it wasn’t simply stretching that drove the results – it was the intensity and duration of the stretch. Participants held deep, high-tension stretches for extended periods, which is very different from a quick post-workout stretch.

While the findings offer an interesting insight into how muscles respond to prolonged stretching, the study also highlights several practical limitations. The protocol required specialised equipment and long, continuous stretches – something that may not be realistic for most people training in a typical gym session.

Still, the results are promising, and further research will help clarify how stretch-mediated hypertrophy works and how it can be applied in everyday training.

The researchers concluded that an eight-week static stretching programme could produce similar increases in strength, muscle thickness and flexibility as traditional resistance training for the chest muscles.

However, because the protocol relied on very long, high-intensity stretches, its real-world practicality may be limited. More research is needed to understand the mechanisms behind these results.

This doesn’t mean swapping your strength workouts for 15-minute stretches on the pec deck.

But the research does reinforce the value of training through a full range of motion, especially when the muscle is in a lengthened position. That might mean lowering deeper into a squat, allowing a fuller stretch at the bottom of a pull-up or pausing in the stretched position during chest flyes.

Some lifters also experiment with ‘long-length partials’ – focusing reps in the stretched part of the movement – to increase tension where the muscle is lengthened.

The takeaway: stretch-mediated hypertrophy is an emerging area of research that could shape how we approach muscle-building in the future.

Kate Neudecker

Kate is a fitness writer for Men’s Health UK where she contributes regular workouts, training tips and nutrition guides. She has a post graduate diploma in Sports Performance Nutrition and before joining Men’s Health she was a nutritionist, fitness writer and personal trainer with over 5k hours coaching on the gym floor. Kate has a keen interest in volunteering for animal shelters and when she isn’t lifting weights in her garden, she can be found walking her rescue dog.