The Claim
In untrained young adults, performing squats with either a 1-second or 4-second eccentric tempo for 7 weeks results in similar increases in total quadriceps cross-sectional area.
What the research says
Challenges is higher
Challenge is ahead, but a single strong supporting 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 untrained young adults, squatting with a 1-second or 4-second lowering phase for 7 weeks produces the same amount of growth in the quadriceps muscle.
See the scientific wording
In untrained young adults, both 1-second and 4-second eccentric tempos during squats for 7 weeks lead to similar increases in total quadriceps cross-sectional area, indicating that overall muscle growth is not significantly affected by eccentric tempo variation.
When you lower yourself slowly during a squat, the muscle fibers under tension for longer grow bigger in specific spots, especially in the part of the thigh that handles endurance. Both slow and fast lowering make the whole thigh bigger overall, but slow lowering makes one part grow more and also makes the muscle stiffer because the tissue changes structure. Fast lowering doesn't change which fibers grow, but still makes the muscle stiffer in another part because of how the muscle handles stretch.
What the research says
1 studyBoth slow and fast squats made thighs bigger overall, but slow squats made one specific part of the thigh muscle grow more than fast squats — so tempo does matter for where the muscle grows, even if total size looks similar.
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.