Case Study: Unfavorable But Transient Physiological Changes During Contest Preparation in a Drug-Free Male Bodybuilder.
Level 4 - case-series / case-control
Single-subject longitudinal case report
PubMed 28770669 · doi:10.1123/ijsnem.2017-0064
What was done
A 13-month longitudinal case study evaluated a competitive drug-free male bodybuilder through 8 months of contest preparation (months 1–8; M1–M8) and 5 months of post-competition recovery (months 8–13; M8–M13). Monthly assessments included serum hormone concentrations (testosterone, T3, T4, cortisol, leptin, ghrelin), body composition via BodPod and DXA, resting metabolic rate (RMR), anaerobic power via the Wingate test, and sleep via the Pittsburgh Sleep Quality Index (PSQI) and actigraphy.
What was found
During preparation (M1 to M8), energy intake decreased from 3,860 to 1,724 kcal/day and the participant lost 9.1 kg. Body fat percentage dropped from 13.4% to 9.6% (BodPod) and from 13.8% to 5.1% (DXA). Testosterone fell from 623 to 173 ng/dL, T3 from 123 to 40 ng/dL, and T4 from 5.8 to 4.1 mg/dL, while ghrelin increased from 383 to 822 pg/mL and cortisol rose from 25.2 to 26.5 mg/dL. Peak anaerobic power decreased from 753.0 to 536.5 W, and RMR dropped from 107.2% to 81.2% of predicted. Subjective sleep quality worsened with minimal change in objective actigraphy. By M13 (recovery), body fat returned to 14.9% (BodPod) and 13.8% (DXA), and physiological alterations were largely, but not entirely, reversed.
Why it matters
This study provides comprehensive longitudinal tracking of the severe endocrine, metabolic, and performance suppression induced by extreme contest dieting, demonstrating that these perturbations are largely reversible with recovery.
Limits
The study is an uncontrolled case report of a single male athlete (n = 1), preventing causal isolation of specific dietary or training variables and limiting generalizability across sexes or different preparation protocols.
Cited by
- supports Severe caloric restriction and reaching single-digit body fat in natural bodybuilders causes extreme suppression of testosterone, resulting in female-equivalent hormone levels.