SOURCE-LINKED STUDY SUMMARY
Testosterone-induced increase in muscle size in healthy young men is associated with muscle fiber hypertrophy.
Abstract summarizedQuality not appraised
- What was studied
- This dose-ranging study examined whether testosterone-related muscle enlargement reflects growth of individual muscle fibres.
- Who / model studied
- 61 healthy men aged 18–35 received treatment. Thigh imaging and paired muscle biopsies were studied in 39 men.
- Studied dose & schedule
- Monthly injections of a hormone-suppressing GnRH agonist plus weekly testosterone enanthate injections of 25, 50, 125, 300 or 600 mg for 20 weeks. Comparisons were across dose groups and against baseline.
- What the study found
- Thigh muscle volume rose with testosterone dose, from a 4 mL decline at 25 mg to a 48 mL gain at 600 mg weekly. Type I fibres enlarged significantly at 300 and 600 mg; type II fibres at 600 mg. Fibre-type proportions did not significantly change.
- Limitations & context
- Study limitations were not stated in the abstract. Methodological quality has not been appraised.
Read summary source ↗ · Prepared 9/24/2026 · AI-assisted, source-based summary
Review record & corrections
Summary prepared: . Source scope: abstract. This is an AI-assisted source summary, not an independent clinician sign-off.
No public field-by-field revision history is available for this card yet. The date above is the summary date, not proof that every field was updated then.
Inspect the source · Correction policyResearch findings apply to the population and conditions studied. This educational summary is not a treatment recommendation or a formal assessment of study quality.
Original publication ↗ · DOI: 10.1152/ajpendo.00502.2001