The Claim
In untrained males performing knee extension exercises to muscular failure at moderate intensity, a 6-second repetition duration protocol produces higher normalized force during the end of the concentric phase (40–30° knee flexion) compared to a 2-second repetition protocol, whereas the 2-second protocol generates greater force during the early range of motion (100–70° knee flexion), suggesting that repetition speed influences the force–angle relationship during dynamic muscle contractions.
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.
If untrained guys do leg extensions slowly (6 seconds per rep) vs. quickly (2 seconds), they’ll push harder at the end of the movement with the slow version, but harder at the start with the fast one — so speed changes where you’re strongest during the lift.
See the scientific wording
In untrained males performing knee extensions to failure at moderate intensity, a 6-second repetition duration protocol results in higher normalized force production at the end of the concentric phase (40–30° knee flexion) compared to a 2-second protocol, while the 2-second protocol generates higher force at the beginning of the range of motion (100–70°), indicating distinct force–angle relationships shaped by repetition speed.
What the research says
1 studyThe study found that slower reps helped build more strength at shorter muscle lengths, and showed that rep speed changes where muscles produce the most force during movement, which supports the claim.
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.