Fig. 1.
Comparison of evidence available to date regarding the effects of low energy availability on reproduction and bone health in exercising men. a The Female Athlete Triad represents a spectrum of energy availability, menstrual health, and bone health status. Within each health category, individuals may vary from optimal health (denoted in green) to compromised health (orange) to a pathological health status (red). b Summary of effects of low energy availability on metabolism, reproduction, and bone health in men supporting the possibility that a similar Triad-like condition may exist in exercising men. REE resting energy expenditure, T3 triiodothyronine, PYY peptide YY, IGF-1 insulin-like growth factor 1, LH luteinizing hormone, P1NP N-terminal propeptide of type I collagen, CTx C-terminal telopeptide type I collagen, BMD bone mineral density, BSI bone stress injury, – indicates no change, ↓ indicates reduced, ↑ indicates increased, ?? indicates unknown