Effect of the intake of high or low glycemic index high carbohydrate-meals on athletes’ sleep quality in pre-game nights

Abstract

This study investigated the effect of the intake of high (HGI) or low glycemic index (LGI) high-carbohydrate meals on athletes' sleep. Nine basketball adult male athletes were assessed during a championship and received high-carbohydrate meals (dinner and evening snack) with HGI or LGI. Quantitative and qualitative sleep variables were assessed: sleep latency (LAT), sleep efficiency (EFIC), Wake After Sleep Onset (WASO), sleep time through actigraphy and sleep diary. Dietary intake, satiety, sleepiness, glycemic response, salivary cortisol and melatonin were also assessed. On both days most athletes had LAT and WASO higher than recommendation, and nocturnal sleep time below the recommendations. There was no difference between sleep and hormonal parameters according to GI dietary manipulations; however, correlations were observed between sleep and diet. Daily energy intake had negative correlation with efficiency and nocturnal total sleep time, and a positive correlation with WASO, regardless of the GI nocturnal meals. No differences were observed in salivary cortisol and melatonin according to GI. The results suggest that food intake throughout the day seems to exert more influence on sleep parameters of basketball players than GI manipulation of evening meals on the pre-night game, but further studies are necessary to better understand this complex relationship.

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].…”

“…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]. According to the "QualSyst" scale, evidence quality of five studies [2,24,[35][36][37] were classified as moderate and six studies [3,23,[31][32][33][34] were classified as strong.…”

“…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]. According to the "QualSyst" scale, evidence quality of five studies [2,24,[35][36][37] were classified as moderate and six studies [3,23,[31][32][33][34] were classified as strong. None of the studies was scored as having weak evidence quality.…”

“…Specifically, eleven comparisons investigated the effect of CHO quantity on sleep [2,24,[31][32][33]36,37] and five investigated the effect of CHO quality on sleep [3,23,34,35]. Of these data sets, seven studied an acute CHO intervention [3,23,[33][34][35], eight studied a short-term (over a period of few days) CHO intervention [2,24,31,32,36,37] and two data sets compared an acute response to a few days of CHO intervention [2]. In Table 2, the consumption of the other two macronutrients, fats and proteins is also presented, as well as the dietary energy content.…”

“…In this manner, between trials dietary fats were substituted by carbohydrates, with no significant modifications in protein intake. Sleep was monitored either with polysomnography or EEG recordings, except for three studies [31,32,35] that measured sleep with actigraphy. The extracted sleep variables for each study are presented in the Table 3.…”