Health Claims

Whether you rest 1 minute or 2.5 minutes between sets, your strength gains in squat and bench press end up being about the same after 10 weeks of training.

Descriptive

If you rest longer between weightlifting sets (2.5 minutes instead of 1 minute), your arms grow bigger over 10 weeks — even if your strength doesn’t change.

Descriptive

When you lift weights and rest only 1 minute between sets, your body releases more stress and sex hormones right after the workout — but only at the very start; after a few weeks, this effect goes away.

Descriptive

If you want to get stronger at squats, doing squats is way better than doing leg extensions — but if you want to get stronger at leg extensions, both exercises work about the same.

Causal

Squats make the outer thigh muscle bigger near the knee more than leg extensions do, but both exercises build it similarly higher up on the thigh.

Causal

Doing leg extensions for 8 weeks makes the front thigh muscle bigger along its whole length more than doing squats, especially near the knee.

Causal

To grow your quads, biceps, and triceps best, it helps to stretch the muscle more during exercise—either by going all the way down or starting the movement early.

Descriptive

When you squat or move your legs wide, using a full motion helps your butt and inner thighs grow more than only doing the top half of the movement.

Descriptive

Doing exercises through a full motion or starting the movement with a shorter motion (but not ending with it) helps your muscles grow more in your thighs and biceps than doing only the last part of the movement.

Descriptive

The way your muscles fire when you do leg presses vs. leg extensions matches up with which muscles end up growing bigger after training.

Descriptive

Leg presses make your butt and inner thigh muscles bigger, but leg extensions don’t affect those muscles at all.

Descriptive

Doing leg presses and leg extensions for 12 weeks both make your main thigh muscles bigger in about the same way, but only leg extensions make the front part of your thigh (rectus femoris) grow significantly.

Descriptive

Leg presses make your butt and inner thigh muscles bigger, but leg extensions don’t — if you want to grow those muscles, leg presses are the better choice.

Descriptive

If you want to make the front part of your thigh (rectus femoris) bigger, leg extensions work better than leg presses — after 12 weeks, leg extensions made it grow 12% more than leg presses did.

Descriptive

Doing leg presses and leg extensions for 12 weeks both make your main thigh muscles bigger about the same amount, but leg presses also make your butt and inner thigh muscles grow more, while leg extensions make the front part of your thigh (rectus femoris) grow much more.

Descriptive

When you train one muscle at a time (like leg extensions), you get a bit better at holding still with that muscle—more than if you train big compound moves like squats. But either way, you get way stronger at moving than holding.

Quantitative

Beginners get way stronger from weight training than experienced lifters, and even among beginners, they get much stronger at moving weights than at holding them still.

Quantitative

Being strong at lifting weights doesn’t mean you’re strong at pushing or pulling and holding still—even with the same muscles—because your body uses different systems for moving vs. holding.

Descriptive

Even though your muscles get bigger and fire more during weight training, those changes don’t explain why you get stronger at dynamic movements but not static holds—something else, like how your brain coordinates the movement, is more important.

Mechanistic

Lifting weights with movement (like squats or bench presses) makes you much stronger at those exact movements, but doesn’t make you much stronger at holding a static position—even if you’re using the same muscles.

Quantitative

The net energy yield from dietary protein is approximately 75% of its caloric content, with only ~25% expended as diet-induced thermogenesis.

Quantitative

Increased total daily energy expenditure from high-protein diets is mediated by elevated fat-free mass resulting from enhanced muscle protein synthesis, not by sustained diet-induced thermogenesis.

Assertion

Chronic elevation of protein intake beyond the threshold required for maximal muscle protein synthesis does not sustainably increase diet-induced thermogenesis or total daily energy expenditure.

Assertion

Diet-induced thermogenesis is significantly higher for dietary protein compared to carbohydrates and fats due to the greater metabolic cost of protein absorption, transport, and amino acid metabolism.

Assertion