The Claim

A single resistance training session consisting of three sets of back-squats to muscular failure at approximately 60% of one-repetition maximum causes a 38.7% reduction in repetitions during the second set and a 54.7% reduction in the third set compared to the first set among resistance-trained men.

Source: Acute and Delayed Effects of a Resistance Training Session Leading to Muscular Failure on Mechanical, Metabolic, and Perceptual Responses.

What the research says

Supports is higher

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

Supports
38score
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.

Quantitative
1 study reviewed
In plain English

Among resistance-trained men, performing three sets of back-squats to muscular failure at 60% of one-rep max results in a 38.7% drop in repetitions in the second set and a 54.7% drop in the third set compared to the first set.

See the scientific wording

A single resistance training session consisting of three sets of back-squats to muscular failure at approximately 60% of one-repetition maximum causes a 38.7% reduction in repetitions during the second set and a 54.7% reduction in the third set compared to the first set, indicating progressive fatigue accumulation within a session among resistance-trained men.

Why this might work

When muscles work hard repeatedly without full recovery, they burn through their quick energy supply, creating waste products that interfere with muscle contraction and signal transmission from the brain. This causes the muscles to produce less force with each set, making it harder to complete the same number of repetitions.

Verified mechanismbased on 1 study

What the research says

1 study
  1. Study: Acute and Delayed Effects of a Resistance Training Session Leading to Muscular Failure on Mechanical, Metabolic, and Perceptual Responses.

    When these trained men did three rounds of squats with moderate weight until they couldn’t do another rep, they could do way fewer reps in the second and third rounds—exactly as the claim says. This proves fatigue builds up fast during one workout.

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

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