Effects of post exercise macronutrient intake timing and composition on recovery

The objective of this dissertation was to determine the importance of macronutrient intake composition and timing following intense endurance exercise (AM exercise; AMex) on subsequent exercise performance 6h later (PM exercise; PMex).; Study 1 demonstrated that, in men, liquid carbohydrate-protein (C+P) supplements ingested early during recovery (within 2h) enhanced (p<0.05) muscle glycogen resynthesis vs. either isoenergetic liquid carbohydrate (CHO) supplements given early during recovery or an isoenergetic solid meal given later during recovery (4h post, PLB) (C+P: +28.62+/-2.10 mmol/L; CHO: +22.20+/-1.19; PLB: +18.59+/-7.67; mean+/-SEM).; Study 2 demonstrated that in men, regardless of supplement composition or timing, PMex performance was diminished relative to AM ex performance; however C+P ingested early during recovery improved subsequent performance (p<0.05) vs. either isoenergetic CHO given early during recovery or isoenergetic PLB given later during recovery (C+P: -0.30+/-0.50 km/h; CHO; -0.99+/-0.44; PLB: -1.36+/-0.75). In addition, estimated fat oxidation was greater during PMex (relative to AMex) in C+P (+5.7g/h) and PLB (+5.4) while it was reduced in CHO (-6.3).; Study 3 suggested that women respond in a similar manner to men although the sample studied was small and, most likely due to low statistical power, significance was not observed for either performance (C+P; -0.98+/-0.17 km/h; CHO: -1.75+/-0.48; PLB: -1.75+/-0.48) or fat oxidation (C+P; +6,6g/h; CHO: -12.9; PLB: +4.5).; Study 4 demonstrated similar blood values (Creatine Kinase, RBC, Hct, Hb, WBC, Fatty Acid Binding Protein, Testosterone, Cortisol, Insulin, Glucagon) in spot samples obtained pre- and post exercise separated by 6h when CHO or C+P were ingested early in recovery. In contrast, insulin and cortisol concentrations prior to PMex were greatest in PLB (p≤0.05), likely due to intake timing (only 2 h prior to PMex).; The studies in this dissertation suggest that early post exercise C+P supplementation (0-2h post) improves muscle glycogen resynthesis, subsequent exercise performance, and fat oxidation relative to either early isoenergetic CHO (0-2h post) or later supplementation (PLB).