If you're already someone who lifts weights, doing light weights twice a week until you can't do more reps can make your muscles bigger and stronger in just 8 weeks.

Scientific Claim

In trained individuals, low-load resistance training to failure at 40% one-repetition maximum for 8 weeks results in significant muscle hypertrophy and strength gains with a sample size of 21 participants and a training frequency of twice per week.

Original Statement

“In the longitudinal study, the same protocol as in the acute study was performed 2 times per week for 8 weeks by 21 volunteers. Both groups showed significant increases in triceps... thigh... and one-repetition maximum...”

From study:Acute and Long-term Responses to Different Rest Intervals in Low-load Resistance Training

Evidence Quality Assessment

Claim Status

appropriately stated

Study Design Support

Design supports claim

Appropriate Language Strength

association

Can only show association/correlation

Assessment Explanation

This is a descriptive report of observed outcomes under specific conditions. No causal or mechanistic claims are made. 'Results in' is acceptable as a description of observed association.

Evidence from Studies

Supporting (1)

Acute and Long-term Responses to Different Rest Intervals in Low-load Resistance Training

Randomized Controlled Trial

Human

2017 Feb

This study found that lifting light weights (40% of max) until you can't do another rep, twice a week for 8 weeks, made people’s muscles bigger and stronger — just like the claim says.

Contradicting (0)

No contradicting evidence found

Source Study

Acute and Long-term Responses to Different Rest Intervals in Low-load Resistance Training

Score: 38

DOI: 10.1055/s-0042-119204

Similar Assertions

You can get stronger and bigger muscles by lifting light weights until you're exhausted — even if you never lift heavy, which challenges the old idea that heavy weights are required.

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Whether you rest 30 seconds or 2.5 minutes between sets of light weightlifting, you end up with about the same muscle growth and strength gains after 8 weeks.

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Even though your body releases similar growth hormones after light workouts whether you rest a little or a lot, you still get stronger and bigger muscles either way.

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Even lifting light weights really slowly until you can't do another rep can make your muscles bigger, just like lifting heavy weights.

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If you're already trained, doing light weights with short or long breaks between sets gives you about the same strength boost in your chest and legs after 8 weeks.

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