Research

Hormonal

Acute postexercise elevations in systemic anabolic hormones (testosterone, growth hormone, IGF-1) are neither necessary nor sufficient to stimulate muscle protein synthesis or drive resistance exercise training-induced hypertrophy.

Stop worrying about the exact time of day you train or trying to manipulate your hormones for better gains. Whether you train in the morning or evening, or whether your hormones fluctuate during your menstrual cycle, does not significantly change your ability to build muscle. Focus on consistent, progressive resistance training rather than trying to 'optimize' your hormonal environment.

StrongRefutesHIGH confidence
Acute increases in anabolic hormones neither enhance muscle protein synthesis nor contribute to muscle hypertrophy with RET. Importantly, acute rises in anabolic hormones and muscle anabolic signaling are also unrelated to longer-term RET-induced skeletal muscle hypertrophic adaptations.
Derrick W. Van Every et al. · Exercise and Sport Sciences Reviews · 2024

Why this rating

Supported by multiple controlled human studies (unilateral training, sex comparisons) showing hypertrophy occurs without hormonal changes.

Source

Hormones, Hypertrophy, and Hype: An Evidence-Guided Primer on Endogenous Endocrine Influences on Exercise-Induced Muscle Hypertrophy

Derrick W. Van Every et al. · Exercise and Sport Sciences Reviews · 2024

DOI 10.1249/jes.0000000000000346

narrative_reviewCited 29×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

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