If you're a young adult who hasn't trained much before and you do squats slowly on the way down for 7 weeks, your thigh muscles might start contracting more slowly, which could mean they're changing to work more like slow-twitch muscles.

If young people who don’t normally lift weights do squats slowly on the way down for 7 weeks, their thigh muscles might start working more like endurance muscles—slower but more tired-resistant.

If you're a young adult who hasn't lifted weights before and you do squats for 7 weeks—whether you lower the bar slowly (4 seconds) or quickly (1 second)—your thigh muscle gets stiffer, and it doesn't matter which speed you use.

If you're a young adult who hasn't trained before and you do squats with either a slow (4-second) or fast (1-second) lowering phase for 7 weeks, your thigh muscles will grow about the same amount either way.

If you're new to lifting and do squats slowly on the way down (4 seconds instead of 1), your front thigh muscle gets bigger faster after 7 weeks.

If you're a young adult who hasn't trained much before, doing squats slowly on the way down (4 seconds) for 7 weeks will make your front thigh muscle grow more than doing it quickly (1 second).