Fast Food Results In Similar Post-exercise Glycogen Recovery And Exercise Performance Compared To Sport Supplements

Abstract

A variety of dietary choices are marketed to enhance recovery after physical activity. These include traditional sports supplements (SS) and even chocolate milk. Previous research indicates that rates of recovery are influenced by macronutrient composition, amount, and timing of ingestion. PURPOSE: This study investigated the effects of SS vs fast food (FF) feedings during a 4-hour recovery period on glycogen recovery and subsequent 20k time-trial performance (TT). METHODS: In a randomized-cross over design, 11 male subjects (4.1±0.62 L/min VO2 max, 78.8±13.6 kg, 31.5±11.5 y), completed a 90-minute glycogen depletion ride on a cycle ergometer. Following 4 hours of recovery a TT was performed. Subjects were fed the same absolute amounts of macronutrients (1.54±0.27 g/kg carbohydrate, 0.24±0.04 g/kg fat, and 0.18±0.03g/kg protein) as either SS or FF items at 0 and 2 hours during recovery with 7 days between trials. Blood samples for glucose and insulin were obtained at 0, 30, 60, 120, 150, 180, and 240 minutes post exercise. Muscle biopsy samples from the vastus lateralis were obtained immediately post exercise and after the 4-hour recovery period for determination of glycogen concentration. A visual analogue gastrointestinal discomfort questionnaire assessing feelings of hunger, fullness, sickness, discomfort, satisfaction, taste, and meal acceptability were administered at 0, 1, 2, 3, and 4 hours of recovery. RESULTS: A feeding effect was observed at time points 30 and 150 minutes for blood glucose and insulin but there were no differences between trials. Rates of glycogen recovery were not different across the diets (6.9±1.7 and 7.9±2.4 mmol.kg− 1 wet weight.hr-1 for SS and FF, respectively). TT results were also not significantly different between trials (34.1±1.8 and 34.3±1.7 minutes for SS and FF, respectively. The questionnaire demonstrated an increase in satiety between 0 and 2 hour feedings for FF (p<0.05). CONCLUSIONS: These data indicate that short-term food options to initiate glycogen recovery can include a wide range of dietary options if total macronutrient composition is considered.