Exercise-Induced Hormone Responses and Their Correlation with Strength/Hypertrophy: A Cohort of 56 Young Men
West DWD, Phillips SM
Evidence is still building up
Summary
In 56 young men, exercise-induced elevations in growth hormone, free testosterone, and IGF-1 did not correlate with gains in lean mass or leg-press strength. Only cortisol and GH showed weak correlations with fiber hypertrophy.
Key findings
- 1
Elevations in testosterone, GH, and IGF-1 did not significantly correlate with gains in muscle size or strength
- 2
Cortisol correlated weakly with lean mass (r=0.29) and type II fiber CSA (r=0.35); GH correlated weakly with fiber hypertrophy (type I r=0.36, type II r=0.28)
- 3
No hormone correlated with strength gains
- 4
Prospective but correlational, with weak effect sizes; testosterone — the hormone central to the myth — was clearly uncorrelated
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