Acute effect of high or low glycemic index meal intake on sleep quality, anxiety and mood of trained individuals

Abstract

Athletic performance is influenced by several factors, including food intake, sleep, and other psychobiological factors. However, there are few studies which investigated the interrelationship of these factors. Therefore, the purpose of this study is to investigate the effect of the intake of high or low glycemic index meals on sleep quality, anxiety, mood and stress of trained individuals serving the Brazilian Army. The procedures will be divided in three stages, coincident with the three annual army Physical Fitness Test (PFT). In the first stage data will be collected to characterize the sample by applying an anamnesis, validated instruments to evaluate anxiety and mood, and body composition assessment. Sleep quality will be evaluated through questionnaires, actigraphy and sleep diaries. Salivary cortisol and melatonin will be measured as well as blood glucose and lipid profile. In the 2nd and 3rd stages, the instruments will be reapplied and the participants will receive a high or low glycemic index (GI) meal, in a crossover controlled randomized design at dinner on the night before the PFT. Individuals will be evaluated for satiety and sleepiness on the morning of the PFT, when they will report how they perceived the quality of their sleep. Before the PFT a usual breakfast will be offered. During and after the exercise information of perceived exertion, sleepness and saciety will be collected. We expect that the study will produce information about the best diet composition to achieve the best sleep quality, to modulate psychobiological factors which affect athletic performance on the night before an exercise session or sport event. (AU)