Does slowing down your leg extension make your thigh bigger?
Effect of different eccentric tempos on hypertrophy and strength of the lower limbs
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
The vastus medialis grew more with slower eccentrics, but the vastus lateralis and rectus femoris didn’t—despite being part of the same muscle group.
Most training advice treats the quadriceps as one unit. This shows regional hypertrophy can be tempo-dependent, which is rarely studied—and contradicts the assumption that all fibers respond uniformly.
Practical Takeaways
If you want to target your vastus medialis (inner thigh) for knee stability or aesthetics, try adding 1–2 sets of slow 4-second eccentrics to your leg extensions.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
The vastus medialis grew more with slower eccentrics, but the vastus lateralis and rectus femoris didn’t—despite being part of the same muscle group.
Most training advice treats the quadriceps as one unit. This shows regional hypertrophy can be tempo-dependent, which is rarely studied—and contradicts the assumption that all fibers respond uniformly.
Practical Takeaways
If you want to target your vastus medialis (inner thigh) for knee stability or aesthetics, try adding 1–2 sets of slow 4-second eccentrics to your leg extensions.
Publication
Journal
Biology of Sport
Year
2021
Authors
P. Azevedo, M. G. D. Oliveira, B. Schoenfeld
Related Content
Claims (6)
How fast or slow you lift and lower weights doesn’t matter as much for building muscle as how much weight you lift, how many reps you do, or how close you push yourself to failure.
If you're a young adult who doesn't lift regularly and you do leg extensions slowly (4 seconds down), your inner thigh muscle gets a little thicker than if you do it faster (2 seconds down)—but the outer and front thigh muscles don't change much.
If you're a young adult who hasn't trained before and you do leg extensions slowly—either taking 2 seconds or 4 seconds to lower the weight—your thigh muscles will grow about the same amount, and you'll get just as strong either way.
If you're a young adult who hasn't trained much before, slowing down the lowering part of a leg extension from 2 seconds to 4 seconds won't make you significantly stronger, even though your muscle is under tension longer.
When you lower a weight slowly (like 4 seconds), your inner thigh muscle (vastus medialis) grows more than the other thigh muscles — the others don’t seem to care as much about the slow lowering.