How different knee exercises grow leg muscles
From full to partials: Investigating the impact of range of motion training on maximum isometric action, and muscle hypertrophy in young women
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Training the final part of the movement (65°–30°) led to the smallest muscle growth despite being a partial range like others.
Many lifters believe that training in a 'stronger' or 'locked-out' range is still effective for growth, but this study shows it’s significantly less effective than training at longer muscle lengths.
Practical Takeaways
Prioritize exercises or reps that include the more extended (lengthened) part of the movement, like the bottom of a squat or leg extension, for better muscle growth.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Training the final part of the movement (65°–30°) led to the smallest muscle growth despite being a partial range like others.
Many lifters believe that training in a 'stronger' or 'locked-out' range is still effective for growth, but this study shows it’s significantly less effective than training at longer muscle lengths.
Practical Takeaways
Prioritize exercises or reps that include the more extended (lengthened) part of the movement, like the bottom of a squat or leg extension, for better muscle growth.
Publication
Journal
Journal of Sports Sciences
Year
2025
Authors
G. Pedrosa, M. Simões, Mariano Rezende Pereira, B. Schoenfeld, Marcel B. Lanza, F. V. Lima, A. Bischoff, M. H. Chagas, R. Diniz
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Claims (5)
Doing only the bottom part of an exercise (where the muscle is stretched) can build as much muscle in your arms and legs as doing the full movement, as long as you put in the same amount of effort and work.
When you do exercises that stretch your muscles more through a bigger movement—like doing full squats instead of tiny half-squats—you may build more muscle tissue than when you stay in a shorter, more restricted movement range.
If young women who don't usually work out do leg exercises focusing on the last part of the knee bend, they get stronger in that exact spot—especially when they train between 65° and 30° of knee bend.
If young women who aren't used to working out do leg exercises focusing on the first part of the knee bend, they get stronger at that specific angle—more than if they did the full movement.
If you're a young woman just starting to lift weights, doing exercises through certain parts of the movement — like the top half or the full motion — helps your leg muscles grow more than doing just the bottom part. Not all shortcuts in the exercise are equally good for building muscle.