The Claim

In amateur bodybuilders, longer rest intervals of 90 seconds and 180 seconds between sets result in significantly greater increases in one-repetition maximum strength for the bench press and back squat compared to 60-second rest intervals, with strength gains of 9.3–10.7% versus 5.9–6.3%.

Source: Effects of Rest Interval Length on Muscle Hypertrophy in Amateur Bodybuilders

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
55score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Cause and effect
1 study reviewed
In plain English

Amateur bodybuilders who rest 90 to 180 seconds between sets gain more strength in the bench press and back squat than those who rest only 60 seconds, with strength increases of 9.3–10.7% compared to 5.9–6.3%.

See the scientific wording

Longer rest intervals (90s and 180s) lead to significantly greater increases in bench press and back squat one-repetition maximum strength compared to 60s rest in amateur bodybuilders, with strength gains of 9.3–10.7% versus 5.9–6.3%, indicating improved capacity to sustain high-quality loading.

Why this might work

Longer breaks between sets let muscles refill their energy stores and clear out fatigue-causing chemicals, so the person can lift heavier weights more times without slowing down. This increases the total force applied to the muscles over the workout, which makes the muscle fibers grow thicker over time, leading to stronger lifts.

Verified mechanismbased on 1 study

What the research says

1 study
  1. Study: Effects of Rest Interval Length on Muscle Hypertrophy in Amateur Bodybuilders

    People who took longer breaks (90 to 180 seconds) between sets got stronger on bench press and squat than those who took only 60-second breaks, because longer breaks let them lift heavier weights more times without getting too tired.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

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

Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.