During a tough leg workout, testosterone levels spike temporarily, but they go back to normal by the next day and don’t stay high.

Scientific Claim

Serum total and free testosterone concentrations increase acutely during heavy resistance exercise in strength-trained men but return to baseline levels within 24 hours, with no sustained elevation during recovery.

Original Statement

“Serum T concentrations increased after the entire course of the exercise from 15.3 ± 3.2 to 19.2 ± 4.5 nmol·L−1 (p < 0.01)... Basal T concentrations... remained unaltered compared to the control day values.”

From study:Recovery after Heavy Resistance Exercise and Skeletal Muscle Androgen Receptor and Insulin-Like Growth Factor-I Isoform Expression in Strength Trained Men

Evidence Quality Assessment

Claim Status

appropriately stated

Study Design Support

Design supports claim

Appropriate Language Strength

association

Can only show association/correlation

Assessment Explanation

The claim accurately reflects the temporal pattern of hormone changes observed without implying causation. The data support a transient association between exercise and testosterone elevation.

Evidence from Studies

Supporting (1)

Recovery after Heavy Resistance Exercise and Skeletal Muscle Androgen Receptor and Insulin-Like Growth Factor-I Isoform Expression in Strength Trained Men

Cohort Study

Human

2011 Mar

After a tough workout, testosterone levels went up right away but came back to normal within two days — so they don’t stay high, which matches what the claim says.

Contradicting (0)

No contradicting evidence found

Source Study

Recovery after Heavy Resistance Exercise and Skeletal Muscle Androgen Receptor and Insulin-Like Growth Factor-I Isoform Expression in Strength Trained Men

Score: 30

DOI: 10.1519/jsc.0b013e318202e449

Similar Assertions

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One workout, whether heavy or high-rep, doesn’t change your testosterone levels in the hours after.

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