Determining the threshold of low energy availability in trained male endurance athletesJurov, Iva (Avtor) Rauter, Samo (Mentor) energy availabilityrelative energy deficiency syndromeendurancemale atletesperformanceThe main issue about energy availability in male athletes still remains poorly understood: when does the low energy availability (LEA) appear and what effects does it have on performance? We aimed to address this question with a strictly controlled intervention study with randomised order of three step energy availability reduction (reduction of 25%, 50% and 75%) in trained and well-trained male endurance athletes. This study modulated participants’ exercise energy expenditure and controlled energy intake and consequently manipulated energy availability in three progressive stages, set to determine potential effects of LEA. All parameters were strictly measured to prevent any error in estimation of energy availability. Performance was measured with three specific tests for explosive power, endurance and agility. Blood was drawn, resting energy expenditure was monitored and two questionnaires were repetitively used to address any changes in eating behaviours and well-being. Repeated measured design showed poorer performance (power output p=.001, relative power output p=.018, explosive power p=.000, lactate concentration p=.001,), the quartile range for testosterone was lower (p=.026), there was a tendency for lower T3 (p=.072). Eating behaviours and well-being were worse (p=.011 and p=.002). The intervention also resulted in lower body fat (p=.013). Based on the results we concluded that the threshold for LEA in men is much lower than 30 kcal/kg FFM/day. We propose using a spectre of 9-25 kcal/kg FFM/day. Reducing energy availability impairs explosive power first, then endurance. It is associated with a reduction in testosterone, T3 and possibly in IGF-1, but hormones are more resilient to changes in energy availability. Psychological assessment of eating behaviours and well-being proved to be very useful, whereas monitoring resting energy expenditure did not.20212021-12-02 07:15:19Doktorsko delo/naloga133576sl