When people train just one leg with heavy weights, their thigh muscles get bigger and stronger—and this method works well for studying how different rest times affect muscle growth.

Scientific Claim

In untrained young men, unilateral resistance training using a within-subject design with volume-load equating can produce measurable hypertrophy in the quadriceps (rectus femoris and vastii) and strength gains in the knee extensors, confirming that this model is effective for studying localized training adaptations.

Original Statement

“Quadriceps regional hypertrophy was evaluated via MRI, and changes in strength were assessed through unilateral knee-extension 1RM testing.”

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 the observed outcomes (hypertrophy and strength gains) without implying causation. The use of MRI and 1RM testing confirms the reliability of the measurements.

Evidence from Studies

Supporting (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 with very short breaks between sets, untrained guys still got stronger and their thigh muscles grew bigger—proving that as long as they do the same total amount of work, the break length doesn’t matter.

Contradicting (0)

No contradicting evidence found

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

The lower part of your thigh doesn’t grow as much from weight training as the upper and middle parts—even if you train hard and use fancy techniques.

74%

When people who’ve never lifted weights before do leg exercises with either 20-second or 2-minute breaks between sets—while doing the same total amount of work—their thigh muscles grow about the same amount.

74%

By having each person train one leg one way and the other leg another way, the study made sure that differences in people’s bodies didn’t mess up the results—so we can be sure it’s the training method, not the person, that matters.

73%

Whether you take short or long breaks between leg exercises, as long as you do the same total number of reps, your inner and outer thigh muscles grow about the same.

73%

If you’re already strong and trained, you don’t need fancy workout tricks like pyramids or going to failure to get the best results—just do the same total work with any method.

71%