Health Claims

Whether you do strength exercises with your muscles stretched out or more shortened, your muscles grow about the same amount in different parts — no big difference.

Descriptive

Even if female athletes eat enough protein, not eating enough total calories can still stop their muscles from getting stronger or recovering properly during training.

Causal

When female athletes don't eat enough, their bodies start breaking down muscle, slow down their metabolism, and reduce key hormones that help build and maintain muscle.

Causal

When female athletes don't eat enough to cover both their workouts and basic body needs, their muscles stop building protein as well, which could make them weaker or slower to recover.

Causal

After a long workout, men and women refill their muscle energy stores at the same rate when they both drink the same recovery drink — even though women burn more fat during the workout.

Descriptive

After a workout, drinking a sugary recovery drink makes your blood sugar and insulin spike higher than if you drink nothing — and this happens the same way in men and women.

Descriptive

A drink with sugar, a little protein, and a tiny bit of fat after a workout helps muscles recover energy, but not quite as well as a drink with just sugar.

Descriptive

After a long workout, drinking a sugary sports drink helps your muscles refill their energy stores much faster than not eating anything at all.

Descriptive

Even though barbell curls put more stress on the biceps when they’re stretched out, they don’t make your biceps grow bigger than cable curls — so stretching the muscle under load isn’t enough to guarantee more growth.

Causal

Men and women both gain the same amount of biceps size and strength from preacher curls — whether they use a cable or barbell — so the training works equally well for both sexes.

Causal

When you do preacher curls for 10 weeks, your strength in the middle and fully bent positions gets better no matter if you use a cable or barbell — the resistance pattern doesn’t make a difference there.

Causal

If you do preacher curls with a barbell — where it’s hardest when your arm is almost straight — you’ll get stronger specifically at that position better than if you use a cable machine where it’s hardest when your arm is bent.

Causal

Whether you use a cable machine or a barbell to do preacher curls for 10 weeks, your biceps will grow about the same amount — the exact way you apply resistance doesn’t matter much for muscle size.

Causal

Overall, your whole triceps muscle grows more when you do the exercise with your arm overhead—even if you’re not lifting as heavy.

Descriptive

Even the smaller parts of your triceps grow more when you do the exercise with your arm overhead instead of at your side.

Descriptive

When you do triceps exercises with your arm stretched overhead instead of at your side, your triceps muscle grows more—even if you’re lifting lighter weights.

Descriptive

Total training volume, training intensity, and consistency are more significant determinants of muscle hypertrophy than the specific muscle length at which training occurs.

Assertion

The hypertrophic response to training at longer muscle lengths may differ between untrained and trained individuals, but current evidence is insufficient to determine this due to limited data in trained populations.

Assertion

Muscle hypertrophic responses to training at different lengths may vary across muscle groups due to differences in architecture, biarticulation, and sarcomere number.

Assertion

Isometric contractions performed at longer muscle lengths produce greater muscle hypertrophy than isometric contractions performed at shorter muscle lengths.

Comparison

When people lift weights through a full motion vs. just part of the motion, the muscles might look like they grow more in one case—but that could just be because the weight feels heavier at different points, not because the muscle is stretched more. So we can’t be sure if stretching the muscle is what’s causing the growth.

Mechanistic

Curling exercises that position the shoulder in extension (lengthening the biceps) produce greater hypertrophy in the biceps brachii compared to exercises that position the shoulder in flexion (shortening the biceps).

Comparison

Overhead triceps extensions, which place the long head of the triceps at a longer muscle length, produce greater hypertrophy in the long head compared to pushdowns that maintain a shorter length.

Comparison

Exercises that position biarticulate muscles at longer lengths (via joint angle manipulation) produce greater hypertrophy in those biarticulate muscle heads compared to exercises that place them at shorter lengths.

Comparison