To keep getting bigger and stronger muscles, you gotta slowly make your workouts harder over time—either lift heavier weights, do more reps, or do more sets.

From: The Top 3 Reasons You’re Not Gaining Muscle

Strongly supported

Multiple high-quality studies back this claim.

53
Pro
0
Against
causal
3 studies

Not medical advice. For informational purposes only. Always consult a healthcare professional.

What this claim means

To keep getting bigger and stronger muscles, you gotta slowly make your workouts harder over time—either lift heavier weights, do more reps, or do more sets.

See the technical phrasing

Sustained muscle hypertrophy in humans requires a gradual increase in training stress over time, achieved through progressive increases in load, volume, or repetitions.

Why this might work
Supported
based on 3 studies

When you lift heavier weights or do more reps over time, your muscle fibers stretch and pull harder, which turns on a molecular switch called mTORC1 that tells the muscle to build more protein — this is how muscles get bigger over time, as shown in studies like 10.1152/physrev.00039.2022, and the fact that people who gradually increase their training load grow more muscle than those who don’t is confirmed by 10.1249/MSS.0000000000003968 and 10.1007/s40279-025-02344-w

What the research says

Supports

3 studies

53

Study: Progressive Overload Affects the Magnitude of Muscle Hypertrophy.

This study provides evidence supporting the claim.

Contradicts

0 studies

0

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 3 supporting studies

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.