By training only one leg at a time, the study made sure that things like overall tiredness or hormones didn’t mess up the comparison between short and long rest periods.

Scientific Claim

In untrained young men, the use of unilateral training to compare 20-second and 2-minute rest intervals minimizes confounding from systemic factors such as hormonal responses or fatigue accumulation across sessions, allowing isolation of rest interval effects.

Original Statement

“Unilateral knee-extension resistance training... [within-subject design]”

From study:Comparison between 20-s and 2-min inter-set rest intervals on changes in muscle cross-sectional area and maximum strength under volume-load-equated resistance training

Evidence Quality Assessment

Claim Status

appropriately stated

Study Design Support

Design supports claim

Appropriate Language Strength

definitive

Can make definitive causal claims

Assessment Explanation

The claim describes a design feature reported in the study without implying causation. The use of unilateral training is a factual methodological choice.

Evidence from Studies

Supporting (0)

No supporting evidence found

Contradicting (1)

Comparison between 20-s and 2-min inter-set rest intervals on changes in muscle cross-sectional area and maximum strength under volume-load-equated resistance training

Randomized Controlled Trial

Human

Even when they used one leg at a time and made sure both groups did the same total work, short rests (20 seconds) and long rests (2 minutes) led to the same muscle growth and strength gains — so the rest time didn’t really matter.

Source Study

Comparison between 20-s and 2-min inter-set rest intervals on changes in muscle cross-sectional area and maximum strength under volume-load-equated resistance training

Score: 51

DOI: 10.1007/s11332-025-01605-5

Similar Assertions

If you take only 20 seconds between sets, you have to do way more sets to match the same total weight lifted as someone taking 2-minute breaks, making your workout longer and more intense.

82%

The strength gains from this study are about what you’d expect from regular weight training—whether you rest a little or a lot—so rest time doesn’t seem to change how much stronger you get.

79%

You don’t need long breaks between sets to get strong—just do the same total amount of work, even with short rests, and you’ll get just as strong.

78%

By training both legs of the same person—one with short breaks, one with long breaks—the study made sure differences weren’t due to people being naturally different, making the results more reliable.

75%

Resting more than a minute and a half between sets doesn’t seem to help you build more muscle than resting for about a minute — it’s not worth the extra time.

75%