The Claim
In untrained young adults performing single-joint upper-body resistance exercises over eight weeks, the use of external momentum during repetitions results in similar increases in muscle thickness and arm circumference compared to strict form, despite a approximately double volume load.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
Over eight weeks, untrained young adults who used momentum while doing bicep curls and triceps pushdowns gained about the same amount of muscle size and arm circumference as those who used strict form, even though they lifted more total weight.
See the scientific wording
In untrained young adults performing single-joint upper-body resistance exercises (biceps curls and triceps pushdowns) for eight weeks, using external momentum ('cheating') during repetitions produces similar increases in muscle thickness and arm circumference as strict form, despite performing approximately double the volume load.
When people swing weights during arm exercises, the muscles still get stretched and pulled hard enough to signal the body to build more muscle, even though they’re not holding the weight as long — the force on the muscle fibers is enough to start the growth process.
What the research says
1 studyPeople who cheated on their arm exercises by swinging the weights gained just as much muscle size as those who did the exercises slowly and carefully—even though they lifted more total weight.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.