Browse evidence-based analysis of health-related claims and assertions
Isolation exercises targeting a single joint (e.g., leg extensions) produce greater hypertrophy in bi-articular muscles (e.g., rectus femoris) compared to multi-joint compound movements (e.g., squats) due to avoidance of active insufficiency.
Comparison
Bi-articular muscles, such as the rectus femoris, exhibit reduced force production during compound movements that demand simultaneous hip and knee extension due to active insufficiency.
Assertion
Increasing rest intervals between sets enhances total training tonnage, which amplifies mechanical tension accumulation and thereby increases the hypertrophic stimulus.
Your muscles grow bigger mainly because of how much total force they feel over time—not whether you do your workouts all at once or spread out over the week.
Mechanistic
Whether you do similar muscle groups together or alternate them, you end up lifting about the same total weight over 8 weeks.
Correlational
If you like doing chest and triceps together or alternating them with back and biceps, pick what you enjoy — both ways work just as well to get stronger and bigger.
Whether you do chest and back exercises together or separately, lifting weights for 8 weeks will make you stronger on the bench press and lat pulldown.
After 8 weeks of lifting weights, whether you do chest and triceps together or alternate them with back and biceps, your arms and chest still get noticeably bigger.
If you're a regular gym-goer, doing workouts that pair similar muscle groups together (like two push exercises) or alternating push and pull exercises both work just as well to build strength and muscle size over 8 weeks.
Different leg exercises make different parts of your thigh muscles bigger — leg extensions grow the front part, squats grow the lower outer part.
Causal
If you want to get stronger at leg extensions, doing squats works just as well as doing leg extensions.
If you want to get stronger at squats, doing squats makes you way stronger than doing leg extensions.
Squats make the outer part of the thigh muscle near the knee bigger than leg extensions do.
Doing leg extensions makes the front thigh muscle bigger along its whole length more than doing squats, especially near the knee.
Even though eating more protein every day makes you burn more calories at rest, it doesn’t make you burn more calories after meals over the long term—your body gets used to it.
When you eat a high-protein meal, your body burns less sugar and more fat for energy right after eating, which might help your metabolism stay flexible and healthy.
It doesn’t matter if your protein comes from chicken, tofu, or whey powder—your body burns about the same number of calories digesting it.
Eating more protein every day for weeks or months makes your body burn more calories even when you’re resting, which might help prevent slow weight gain over time.
Eating a meal with more protein makes your body burn more calories right after eating—but only if you’re not overweight; if you are, this calorie-burning boost doesn’t happen.
If you're a regular gym-goer, doing workouts that group similar muscle moves together or alternate them doesn't seem to make a difference in how much stronger or bigger your muscles get after 8 weeks.
Even though eating more protein makes you burn more calories right after a meal, your body gets used to it over time — so after weeks, that extra calorie burn disappears.
When you eat a high-protein meal, your body starts burning more fat and less sugar for energy right after eating.
Whether you get your protein from chicken, tofu, milk, or fish, it doesn’t make your body burn more calories — the amount of protein matters more than the source.
Eating more protein every day for weeks or months makes your body burn more calories even when you’re resting — even if you don’t lose weight.