Mixed
When resistance training sets are performed to momentary muscular failure, low-load training (≤60% 1RM) produces muscle hypertrophy equivalent to high-load training (>60% 1RM).
If you want to build muscle but only have light dumbbells or bodyweight, you can still get great results. The key is to perform your sets until you physically cannot complete another repetition with good form (momentary muscular failure). You will likely need to do more repetitions (e.g., 20-30+) compared to heavy lifting, but the muscle growth will be the same as if you were lifting heavy weights.
Changes in measures of muscle hypertrophy were similar between conditions. The findings indicate that maximal strength benefits are obtained from the use of heavy loads while muscle hypertrophy can be equally achieved across a spectrum of loading ranges.
Why this rating
Systematic review and meta-analysis of 21 randomized controlled trials with good-to-excellent methodological quality (PEDro score mean 5.6).
Source
Strength and Hypertrophy Adaptations Between Low- vs. High-Load Resistance Training: A Systematic Review and Meta-analysis
Brad J. Schöenfeld et al. · The Journal of Strength and Conditioning Research · 2017
This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →