Two Days Of Low Energy Availability Does Not Impair Exercise Performance In Resistance-trained College-age Men

PURPOSE: To quantify the impact of an acute low energy availability (LEA) state induced by severe energy restriction between two exercise sessions on plyometric and resistance exercise performance. METHODS: In a block-randomized, repeated measures trial, eight resistance-trained men (20.0 ± 0.76 years, 93.4 ± 15.2 kg, 18.7 ± 5.9% body fat) consumed either LEA (15 kcal · kg FFM-1 · day-1) or control (CON; 45 kcal · kg FFM-1 · day-1) diets for two days before and after which they achieved a one-repetition maximum (1RM) on the barbell bench press exercise, performed countermovement vertical jumps on a Leonardo Mechanograph Ground Reaction Force Plate Lite (Novotec Medical GmbH, Pforzheim, Germany) and completed two isokinetic protocols on a BioDex System 4 Quick-Set isokinetic dynamometer (BioDex Medical Systems, New York, USA). On the dominant leg, one set each of leg extensions and leg curls was performed to fatigue, operationally defined as three consecutive repetitions below 50% of peak torque achieved during the set. On the non-dominant leg, three sets of 10 repetitions of leg extensions and leg curls were performed at maximal effort on each repetition with 90 seconds of rest between the sets. Performance in each exercise modality was assessed using Mixed-Design ANOVA with the significance level set at p < .05 after correction for multiple tests. RESULTS: LEA reduced body mass compared to CON (-2.05 ± 0.83 kg vs -0.40 ± 0.48 kg, p < .001). No main effects of condition were observed for 1RM performance (Pre-CON: 120 ± 16 kg; Post-CON: 118 ± 16 kg; Pre-LEA: 118 ± 14 kg; Post-LEA: 117 ± 13 kg), vertical jump height (Pre-CON: 61 ± 6 cm; Post-CON: 62 ± 8 cm; Pre-LEA: 59 ± 7 cm; Post-LEA: 61 ± 7 cm) nor total work performed during the two different isokinetic protocols on the dominant (Pre-CON: 8441 ± 1592 Nm; Post-CON: 8307 ± 1919 Nm; Pre-LEA: 8594 ± 1382 Nm; Post-LEA: 7919 ± 1247 Nm) and non-dominant (Pre-CON: 9546 ± 1391 Nm; Post-CON: 9274 ± 1331 Nm; Pre-LEA: 9608 ± 1742 Nm; Post-LEA: 9063 ± 1627 Nm) legs, respectively. CONCLUSIONS: Two days of severe energy restriction following a plyometric and resistance exercise session did not impair performance in the subsequent exercise bout. Supported by: This project was funded via internal funding from South Dakota State University.