Effects Of Time-restricted Feeding On Supramaximal Exercise Performance: A Randomized And Counterbalanced Crossover Study In Healthy Men

PURPOSE: Limited data exist on the interaction between time-restricted feeding (TRF) and supramaximal exercise performance. Using a crossover design, we explored the effects of both short- and long-term TRF vs. regular diet on Wingate (WnT) performance and body composition in well-trained young men. METHODS: Twelve healthy male physical education students were included (age: 22.4 ± 2.8 years). The order of dieting was randomized and counterbalanced, and all participants served as their own controls. TRF was limited to an 8-h eating window and non-TRF involved a customary meal pattern. Participants performed WnT tests at baseline, post-1 and 4 weeks of the assigned diet. Before testing, participants were asked to fill out a dietary record over 4 consecutive days and were instructed to continue their habitual training throughout the study. RESULTS: We obtained a significant condition x time interaction for WnT absolute mean power (F = 5.6, p = 0.037; ES = 0.34) and for total work (F = 5.6, p = 0.038; ES = 0.32). Absolute mean power increased from pre- to post-4 weeks of TRF (pre-intervention: 563.2 ± 101.9 vs. post-intervention: 584.9 ± 101.8; p = 0.04), but no significant changes were observed for the non-TRF condition (pre-intervention: 579.5 ± 88.4 vs. post-intervention: 579.4 ± 83.8; p > 0.05). Similar findings were also obtained for total work [(pre-TRF: 16895.7 ± 3058.7 vs. post-TRF: 17547.5 ± 3056.0; p < 0.05); (pre-non-TRF: 17386.7 ± 2652.2 vs. post-non-TRF: 17382.1 ± 2513.2; p > 0.05)]. WnT relative mean power also exhibited a trend toward a differential response between conditions (condition x time interaction: F = 4.5, p = 0.058; ES: 0.29). Finally, neither condition was effective in eliciting any changes in WnT performance 1 week post-intervention. CONCLUSIONS: Long- but not short-term TRF can be used in combination with regular training to improve supramaximal exercise performance in young, well-trained men.