Browse evidence-based analysis of health-related claims and assertions
Doing leg extensions makes the front thigh muscle grow more evenly along its length than doing squats, which don’t stimulate that muscle as much.
Causal
The side muscle of your thigh doesn’t grow any more with drop sets than with regular sets—no matter where you measure it.
Drop sets don’t make you do more reps or sets, but they let you lift heavier weights for more total work—which is probably why your muscle grows more in some spots.
Quantitative
When guys who never lifted weights before started doing leg workouts for 15 weeks, their thigh muscles got 12.7% bigger—and super-precise MRI scans proved it, showing this tech is great for tracking muscle growth.
When scientists look at how one person changes over time—like how their muscles grow and get stronger together—they find a super strong link. But when they compare different people to each other, that link looks much weaker.
Correlational
When guys who’ve never lifted weights start training, most of their strength gains come from their muscles getting bigger—not from their brain and nerves getting better at telling muscles to work harder.
When guys who’ve never lifted weights before start training, the more their thigh muscles ‘fire up’ during max efforts, the stronger they tend to get—both in holding a heavy position and in lifting one heavy weight.
When guys who’ve never lifted weights before train their legs for 15 weeks, the more their muscles grow, the stronger they get—so muscle growth is mostly why they get stronger.
Single-leg lunges helped both legs get better at turning quickly, but double-leg squats only helped the stronger leg.
Both training methods made athletes jump higher and turn faster, but didn’t make them run straight-line sprints any faster.
Single-leg lunges helped athletes slow down better with their weaker leg after turning, more than double-leg squats did.
Both types of training made athletes stronger and more powerful, but squats with both legs made them significantly more powerful in the squat than lunges did.
Doing squats with both legs on a special machine for six weeks made the outer thigh and outer calf muscles grow more than doing single-leg lunges.
Doing single-leg lunges with a special machine for six weeks made the inner thigh and inner knee muscles grow more than doing regular squats with both legs.
How much your butt muscles 'fire up' during your first hip thrust or squat doesn’t tell you how much they’ll grow over time — the feeling during the workout isn’t a reliable guide to results.
Doing squats or hip thrusts helps you get stronger at deadlifts and pushing against a wall about the same amount — neither exercise gives you a big edge over the other for these other movements.
If you want to get stronger at squats, you need to squat; if you want to get stronger at hip thrusts, you need to do hip thrusts. Training one doesn’t make you much stronger at the other.
Squats build your thigh muscles (quads and inner thighs) more than hip thrusts do, because squats involve more knee and hip movement that engages those muscles more.
Doing hip thrusts or squats for 9 weeks with the same total work builds your butt muscles just as much, even though hip thrusts feel like they work your butt harder during the exercise.
BFR training doesn't make you stronger at lifting your heaviest weight — it helps with endurance and muscle size, but not with max strength tests like a one-rep max.
When you do BFR training, your muscles grow more in the middle and lower parts of your thigh than near your hip — meaning the effect is strongest where the blood flow is most restricted.
New lifters of all ages and genders get stronger faster with heavy weights than with light weights and blood flow restriction — no matter how long they train or whether they're male or female.
For most people, lifting light weights with blood flow restriction builds muscle just as well as lifting heavy weights — making it a great option if you can't lift heavy.
If you're new to lifting weights, heavy lifting makes you stronger faster than light lifting with blood flow restriction, but both methods build muscle about the same.