The Claim
High-intensity resistance training at 90% one-repetition maximum improves horizontal countermovement jump distance in male academy soccer players, whereas moderate-intensity resistance training at 80% one-repetition maximum does not improve horizontal countermovement jump distance in the same population, despite both training intensities improving vertical jump performance and maximal strength.
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.
Male academy soccer players who train with heavy weights (90% of their maximum lift) jump farther horizontally after training than those who train with moderate weights (80% of their maximum lift), even though both groups improve their vertical jump height and strength.
See the scientific wording
High-intensity resistance training (90% 1RM) improves horizontal countermovement jump distance in male academy soccer players, while moderate-intensity training (80% 1RM) does not, despite both improving vertical jump and strength outcomes.
Lifting very heavy weights forces the body to activate the strongest muscle fibers that fire quickly, which makes the legs push off the ground faster and harder during a forward jump. Lighter weights don't do this as effectively, even if they make the muscles bigger or stronger in general.
What the research says
1 studyHeavy squats made soccer players jump farther forward, but lighter squats didn’t—even though both made them stronger and better at jumping up. So heavy lifting is special for forward jumps.
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.