The Claim
Resistance training performed at longer muscle lengths results in a greater increase in elbow flexor cross-sectional area compared to resistance training performed at shorter muscle lengths.
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.
When performing resistance exercises that stretch the elbow flexor muscles more, the muscles grow larger in cross-sectional area than when the same exercises are done with less stretch.
See the scientific wording
Resistance training at longer muscle lengths increases elbow flexor cross-sectional area more than training at shorter muscle lengths.
When a muscle is kept stretched while lifting weight, the fibers and surrounding structures experience more sustained pull. This pull activates a cellular signal that tells the muscle to build more protein, especially in the part of the muscle that's stretched the most, making that area thicker over time.
What the research says
4 studiesWhen people did arm curls with their elbows only bending partway (keeping the biceps stretched), their biceps grew a little more in the stretched area than when they curled all the way up and down. So stretching the muscle more during exercise might help it grow bigger.
Study: Mixing Up Muscle Lengths: The Effects of Training at Different Muscle Lengths in the Elbow Flexors
This study found that doing bicep curls with your arm stretched out more made your biceps grow bigger than doing curls with your arm more bent. So, stretching the muscle while lifting helps it get bigger.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 4 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.