Effects of High vs. Low Glycemic Index of Post-Exercise Meals on Sleep and Exercise Performance: A Randomized, Double-Blind, Counterbalanced Polysomnographic Study

Abstract

The aim of the current study was to investigate the effect of the glycemic index of post-exercise meals on sleep quality and quantity, and assess whether those changes could affect the next day’s exercise performance. Following a baseline/familiarization phase, 10 recreationally trained male volunteers (23.2 ± 1.8 years) underwent two double-blinded, randomized, counterbalanced crossover trials. In both trials, participants performed sprint interval training (SIT) in the evening. Post-exercise, participants consumed a meal with a high (HGI) or low (LGI) glycemic index. Sleep parameters were assessed by a full night polysomnography (PSG). The following morning, exercise performance was evaluated by the countermovement jump (CMJ) test, a visual reaction time (VRT) test and a 5-km cycling time trial (TT). Total sleep time (TST) and sleep efficiency were greater in the HGI trial compared to the LGI trial (p < 0.05), while sleep onset latency was shortened by four-fold (p < 0.05) and VRT decreased by 8.9% (p < 0.05) in the HGI trial compared to the LGI trial. The performance in both 5-km TT and CMJ did not differ between trials. A moderate to strong correlation was found between the difference in TST and the VRT between the two trials (p < 0.05). In conclusion, this is the first study to show that a high glycemic index meal, following a single spring interval training session, can improve both sleep duration and sleep efficiency, while reducing in parallel sleep onset latency. Those improvements in sleep did not affect jumping ability and aerobic endurance performance. In contrast, the visual reaction time performance increased proportionally to sleep improvements.

A Systematic Review, Meta-Analysis and Meta-Regression on the Effects of Carbohydrates on Sleep

“…Included studies were published from 1975 to 2019. Eight studies used a cross-over design [ 3 , 23 , 24 , 31 , 32 , 33 , 34 , 35 ] and three used a single group pre-post design [ 2 , 36 , 37 ]. Three studies were conducted in the United Kingdom [ 24 , 33 , 36 ], three in Australia [ 2 , 23 , 34 ], three in United States [ 31 , 32 , 37 ], one in Cyprus [ 3 ] and one in Brazil [ 35 ].…”

“…It is defined as a reversible state of decreased or absent consciousness that initiates from wakefulness and evolves to light, deep and rapid eye movement (REM) sleep stages [ 1 ]. Alterations in sleep-related parameters are often part of physiological responses that may be induced by nutrition interventions and might be translated into modifications in sleep architecture [ 2 ], quantity or continuation [ 3 ].…”

“…Two recent reviews suggest that dietary melatonin intake (either from fruits and vegetables [ 21 ], or milk and cherry juice [ 22 ]) could have sleep-promoting effects. Research shows that carbohydrates are associated with alterations in sleep onset latency [ 23 ], sleep time [ 3 ], sleep continuity [ 3 ] and sleep stages [ 24 ]. Nonetheless, the effect of CHO intake in sleep has not been systematically reviewed yet.…”

High-Intensity Interval Exercise Performance and Short-Term Metabolic Responses to Overnight-Fasted Acute-Partial Sleep Deprivation

“…Moreover, it has been shown that the timing of the food intake and its composition are correlated with negative effects on sleep quality [ 43 ]. Our study’s design with its light meal composition allowed for adequate time between the last meal and preparations for sleep, while supported the body with CHO to improve sleep and the next day’s aerobic performance [ 103 ]. It is apparent that all of the aforementioned studies, including ours, have used different populations, applied exercise protocols, and patterns of sleep manipulation, factors that have been discussed to be reasons for discrepancies [ 19 , 26 ].…”

Advances in Sport and Performance Nutrition

“…The amount and the type of carbohydrates (i.e., low glycemic index versus high glycemic index [3]) in sport nutrition has been an important field of investigation in the last decades. The novelty of the paper of Vlahoyiannis and co-workers [4] is the focus on the effects of the high or low glycemic index of a post-exercise meal on another “hot” topic in sport and performance: the quality of sleep. They suggested that a high glycemic index meal, following a single spring interval training session, can improve both sleep duration and sleep efficiency, while reducing in parallel sleep onset latency.…”