Browse evidence-based analysis of health-related claims and assertions
After losing weight, people with prediabetes who eat more protein burn more calories at rest and end up in a calorie deficit, which could help them keep the weight off longer.
Causal
Just because certain muscle traits make someone strong right now doesn’t mean those same traits will help them get stronger from training—what matters for improvement is different.
Correlational
Even if you rest only 20 seconds between sets instead of 2 minutes, as long as you do the same total number of reps and weight, your muscles still grow and get just as strong.
The biggest reason people get stronger during dynamic leg movements after training isn’t just muscle growth—it’s how much their brain tells their thigh muscles to fire harder.
If you do the same total amount of weightlifting work, it doesn’t matter much if you rest 20 seconds or 2 minutes between sets—your muscles grow and get stronger about the same either way.
When untrained men get stronger during dynamic leg movements like standing up, the biggest factor is how much their thigh muscles fire, especially when combined with changes in the deep thigh muscle’s fiber angle and overall muscle size.
Deep squats help young tennis players lose more body fat than shallow squats—even when they do the same number of reps and weights—possibly because they work harder and burn more energy.
Even though deep squats move your legs through a bigger range, they don’t make your muscles bigger than shallow squats—if you’re doing the same number of reps and weights.
Mechanistic
Doing squats twice a week for 8 weeks makes young tennis players stronger and leaner, no matter if they go deep or shallow—as long as they lift enough weight.
Whether young tennis players do deep or shallow squats, their leg muscles grow just as big—as long as they do the same number of reps and weights.
Hip thrusts turn on your butt and hamstrings more than squats, but both exercises work your front thigh muscles just as hard.
Descriptive
When comparing hip thrusts and squats at the same effort level, the front thigh muscle (quadriceps) works just as hard in both exercises.
When doing a hip thrust with a barbell instead of a squat, the butt and back of the thighs light up more on muscle sensors during the same level of effort.
What makes someone strong right now isn’t the same as what makes them get stronger after training — your starting point doesn’t tell you how much you’ll improve.
For the outer calf and deep calf muscle, it doesn’t seem to matter much whether you do straight-leg or seated calf raises — both work about the same.
When you get stronger holding a position (like pushing against a wall), your muscle size matters more — but when you’re moving (like kicking a ball), how hard you activate your muscles matters more than how big they are.
Even though the vastus intermedius is a deep thigh muscle you can't see, its fiber angle changes were linked to better leg strength during both pushing and lowering movements — it might be more important than it looks.
The type of leg exercise you do — whether it’s a leg press, leg extension, or calf raise — can change which part of your leg muscles grow bigger, and you can see the difference in just 8 weeks.
Men who started with a longer tendon lever arm and could already activate their thigh muscles better tended to get stronger in eccentric movements after training — their starting point mattered.
If you want to grow the inner part of your calf muscle, doing straight-leg calf raises might work better than seated ones.
When untrained men get stronger during dynamic leg extensions, the biggest factor is how much they can turn on their thigh muscles — bigger muscles and fiber angles help a little, but turning on the muscles harder matters most.
If you want to grow the outer part of your thigh (vastus lateralis), leg presses might be more effective than leg extensions.
If you want to grow the front part of your thigh muscle (rectus femoris), doing leg extensions might work better than doing leg presses.
When untrained men get stronger in a static leg press, the main reason is that their thigh muscle near the hip gets bigger and its fibers angle more, which helps push harder.