The Claim
When both the concentric and eccentric phases of resistance exercise are manipulated in tandem—comparing fast-fast tempos to slow-slow tempos—there is no significant difference in muscle hypertrophy outcomes.
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 you lift and lower weights quickly or slowly, as long as you do both phases the same way, your muscles grow about the same amount—speed doesn’t make a big difference.
See the scientific wording
When both concentric and eccentric phases are manipulated in tandem (fast-fast vs. slow-slow), no significant difference in muscle hypertrophy is observed.
What the research says
2 studiesThe study had people lift weights fast or slow, both on the way up and down, and found that no matter which speed they used, their muscles grew about the same amount.
The study found that lifting weights quickly or slowly doesn’t make a meaningful difference in muscle growth — so whether you go fast-fast or slow-slow, your muscles grow about the same.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 2 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.