Abstract
Objective: The purpose of this study was to investigate the effects of “train-high sleep-low” (THSL) dietary periodization on ventilatory strategies during cycling exercise at submaximal and maximal intensities.
Method: In a randomized crossover design, 8 trained men [age (mean ± SEM) = 28 ± 1 y; peak oxygen uptake = 56.8 ± 2.4 mL kg−1 min−1] completed two glycogen-depleting protocols on a cycle ergometer on separate days, with the cycling followed by a low carbohydrate (CHO) meal and beverages containing either no additional CHO (THSL) or beverages containing 1.2 g kg−1 CHO [traditional CHO replacement (TRAD)]. The following morning, participants completed 4 minutes of cycling below (Stage 1), at (Stage 2), and above (Stage 3) gas exchange threshold, followed by a 5-km time trial.
Results: Timetrial performance was significantly faster in TRAD compared to THSL (8.7 ± 0.3 minutes and 9.0 ± 0.3 minutes, respectively; p = 0.02). No differences in ventilation, tidal volume, or carbon dioxide production occurred between conditions at any exercise intensity (p > 0.05). During Stage 1, oxygen uptake was 37.9 ± 1.5 mL kg−1 min−1 in the TRAD condition and 39.6 ± 1.8 mL kg−1 min−1 in THSL (p = 0.05). During Stage 2, VO2 was 44.6 ± 1.7 mL kg−1 min−1 in the TRAD condition and 47.0 ± 1.9 mL kg−1 min−1 in THSL (p = 0.07). No change in operating lung volume was detected between dietary conditions (p > 0.05).
Conclusions: THSL impairs performance following the dietary intervention, but this occurs with no alteration of ventilatory measures.
Acknowledgements
We would like to thank the participants of our study.
Conflict of interest
We declare that we have no conflict of interest.