The Claim
In resistance-trained men, 8 weeks of unilateral leg extensions with a fast eccentric tempo (1-0-1) results in a 5.5% increase in distal quadriceps muscle thickness compared to a slow eccentric tempo (1-0-3), with identical training volume and intensity.
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.
In men trained in resistance exercise, performing leg extensions with a faster lowering phase for 8 weeks increases the thickness of the lower part of the quadriceps muscle by 5.5% compared to a slower lowering phase, when total workload and intensity are kept the same.
See the scientific wording
In resistance-trained men, performing 8 weeks of unilateral leg extensions with a fast eccentric tempo (1-0-1) produces a small but statistically significant increase in distal quadriceps muscle thickness (5.5%) compared to a slow eccentric tempo (1-0-3) (2.2%), despite identical training volume and intensity, suggesting regional hypertrophic adaptations may be influenced by contraction speed in trained individuals.
When the muscle is lowered quickly during a leg extension, the muscle fibers stretch faster, which triggers stronger mechanical signals in the lower part of the thigh. These signals activate a cellular growth pathway that builds more muscle protein specifically in that region.
What the research says
1 studyIn guys who lift weights, lowering the weight faster during leg extensions for 8 weeks made the lower part of their thigh muscles grow a little more than lowering it slowly—even when they did the same total amount of work.
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.