Intake of Protein Plus Carbohydrate during the First Two Hours after Exhaustive Cycling Improves Performance the following Day

Abstract

Intake of protein immediately after exercise stimulates protein synthesis but improved recovery of performance is not consistently observed. The primary aim of the present study was to compare performance 18 h after exhaustive cycling in a randomized diet-controlled study (175 kJ·kg-1 during 18 h) when subjects were supplemented with protein plus carbohydrate or carbohydrate only in a 2-h window starting immediately after exhaustive cycling. The second aim was to investigate the effect of no nutrition during the first 2 h and low total energy intake (113 kJ·kg-1 during 18 h) on performance when protein intake was similar. Eight endurance-trained subjects cycled at 237±6 Watt (~72% VO2max) until exhaustion (TTE) on three occasions, and supplemented with 1.2 g carbohydrate·kg-1·h-1 (CHO), 0.8 g carbohydrate + 0.4 g protein·kg-1·h-1 (CHO+PRO) or placebo without energy (PLA). Intake of CHO+PROT increased plasma glucose, insulin, and branch chained amino acids, whereas CHO only increased glucose and insulin. Eighteen hours later, subjects performed another TTE at 237±6 Watt. TTE was increased after intake of CHO+PROT compared to CHO (63.5±4.4 vs 49.8±5.4 min; p<0.05). PLA reduced TTE to 42.8±5.1 min (p<0.05 vs CHO). Nitrogen balance was positive in CHO+PROT, and negative in CHO and PLA. In conclusion, performance was higher 18 h after exhaustive cycling with intake of CHO+PROT compared to an isocaloric amount of carbohydrate during the first 2 h post exercise. Intake of a similar amount of protein but less carbohydrate during the 18 h recovery period reduced performance.

National Athletic Trainers' Association Position Statement: Fluid Replacement for the Physically Active

“…220,232,233 In some cases, adding protein to a sports drink may improve exercise performance. 234 Rates of gastric emptying and intestinal absorption (the primary site of fluid absorption) influence rehydration, especially during exercise. 80,84,229 Fluid volume, fluid calorie content, fluid osmolality, exercise intensity, environmental stress, and fluid temperature are important factors that determine these rates.…”

Eight sessions of endurance training decrease fasting glucose and improve glucose tolerance in middle-aged overweight males

“…Carbohydrate is the main energy substrate during exercise at intensities ~75% of maximal oxygen uptake (Hermansen, Hultman, & Saltin, 1967;Romijn et al, 1993;Rustad et al, 2016;Sollie et al, 2018), and prolonged training at such intensities improves glucose tolerance. Moreover, exercise at such intensity effectively improves skeletal muscle oxidative capacity and expression of many proteins involved in glucose uptake.…”

Hyperproteic supplementation attenuates muscle damage after simulated Olympic cross-country mountain biking competition: a randomized case-control study

“…Like the present protocol, other studies have investigated the effect of post-exercise supplementation in muscle damage. Rustad, et al 41 did not observe a difference in muscle damage (CPK and LDH) 18 hours after a maximal cycling test when athletes consumed carbohydrate (1.2 g/kg BW) or CHO-PRO (0.8 + 0.4 g/kg BW), but CHO-PRO resulted in positive nitrogen balance and better performance after the recovery. There is still no clarity about the recuperative effect of CHO and PRO on muscle damage enzymes; Brown, Stevenson and Howatson 42 found that the intake of whey protein (20 g) compared to CHO (21.8 g) resulted in a lower concentration of CPK 48-hours after sprinting (15 X 30 m).…”