"Train-High Sleep-Low" Dietary Periodization Does Not Alter Ventilatory Strategies During Cycling Exercise. (18th May 2020)

• Record Type: Journal Article
• Authors: Paris, Hunter L.; Fulton, Timothy J.; Wilhite, Daniel P.; Baranauskas, Marissa N.; Chapman, Robert F.; Mickleborough, Timothy D.
• Is Part Of: Journal of the American College of Nutrition. Volume 39:Number 4(2020)
• Page Start: 325
• Page End: 332
• Publication Date: 2020-05-18
• Subjects: Diets -- exercise -- sports nutrition -- general nutrition -- metabolism; Nutrition -- Periodicals; Nutrition disorders -- Periodicals; 613.2
• DOI: 10.1080/07315724.2019.1654419
• Languages: English
• ISSNs: 0731-5724

Abstract

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.