The Claim
Twelve weeks of resistance training increases both type I and type II muscle fiber cross-sectional area in the biceps brachii of college-aged men, as measured by muscle biopsy analysis, with type I fibers increasing from 4,196 ± 859 to 4,617 ± 1,116 μm² and type II fibers increasing from 6,378 ± 1,552 to 7,474 ± 2,017 μm².
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.
Lifting weights for three months makes the muscle fibers in young men's biceps get bigger — both the endurance-type and power-type fibers.
See the scientific wording
Twelve weeks of resistance training increases type I and type II muscle fiber cross-sectional area in the biceps brachii of college men, with type I fibers growing from 4,196 ± 859 to 4,617 ± 1,116 μm² and type II fibers from 6,378 ± 1,552 to 7,474 ± 2,017 μm², based on muscle biopsy analysis.
What the research says
1 studyThe study looked at college guys doing weight training for 12 weeks and found their biceps muscle fibers got bigger, just like the claim says.
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.