"Train-High Sleep-Low" Dietary Periodization Does Not Alter Ventilatory Strategies During Cycling Exercise

• Published in: Journal of the American College of Nutrition 2020-05, Vol.39 (4), p.325-332
• Main Authors: Paris, Hunter L., Fulton, Timothy J., Wilhite, Daniel P., Baranauskas, Marissa N., Chapman, Robert F., Mickleborough, Timothy D.
• Format: Article
• Language: English
• Subjects: Diets; exercise; general nutrition; metabolism; sports nutrition
• ISSN: 0731-5724; 1541-1087
• DOI: 10.1080/07315724.2019.1654419

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.