Simultaneous post-exercise carbohydrate and protein intake does not improve next-day performance in trained cyclists

DOI: https://doi.org/10.1123/ijsnem.2021-0069

Explanation

In general, post-exercise carbohydrate (CHO) intake is believed to enhance recovery from endurance exercise.

In this study, we were investigating whether adding protein to recovery drinks to optimize CHO intake would improve 24-hour recovery.

Using a double-blind crossover design, 12 trained men performed three trials of constant-load exercise to reduce glycogen on day 1, followed by consumption of a CHO beverage (1.2 g/kg -1/2 h -1) for two days.

Blood glucose and insulin responses were analyzed for 2 hours after estimation, with and without whey protein concentrate (CHO + PRO) and whey protein hydrolysate (CHO + PROH) (0.3 g/kg -1/2 h-1).

The day after another round of glycogen-reducing exercise, time trial performance was measured, and there were no differences in 30-minute time trial performance among the three trials. There was no significant difference in glucose disposal between the post-exercise conditions.

Insulin AUC was lower in CHO, compared to CHO + PRO and CHO + PROH, and there was no difference in insulin AUC between CHO + PRO and CHO + PROH.

Despite the high acute insulin response, we did not find that adding protein to a CHO-based recovery drink after prolonged high-intensity exercise did not alter exercise capacity the following day when overall 24-hour macronutrient and caloric intake was controlled.