Research

Hormonal

Competition preparation in physique athletes, characterized by severe energy restriction and intense training, causes significant reductions in IGF-1, IGFBP-3, and testosterone, along with increased cortisol and SHBG, leading to decreased muscle strength and mood disturbances, all of which are reversible upon recovery.

If you are preparing for a physique competition, expect significant drops in IGF-1, testosterone, and strength, along with increased fatigue and mood disturbances. These are normal, adaptive responses to severe energy restriction and intense training. Do not panic about temporary hormonal suppression; they will fully recover during the post-competition refeeding phase. Monitor your energy availability, but understand that some performance and hormonal decline is inevitable during the peak week.

GoodSupportsHIGH confidence
During the diet, EA (p < 0.001), IGF-1 (p < 0.001), IGFBP-3 (p < 0.01), and absolute muscle strength (p < 0.01–0.001) decreased significantly in both sexes in COMP... In males, testosterone (p < 0.01) and free testosterone (p < 0.05) decreased, while SHBG (p < 0.001) and cortisol (p < 0.05) increased... All these changes were restored by increased EA during the post-competition recovery period.
Ville Isola et al. · European Journal of Applied Physiology · 2024

Why this rating

Randomized controlled trial design with control groups, though self-managed diet/training introduces variability.

Source

Changes in hormonal profiles during competition preparation in physique athletes

Ville Isola et al. · European Journal of Applied Physiology · 2024

DOI 10.1007/s00421-024-05606-z

cohort · n=43Cited 5×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

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