Ingestion of carbohydrate or carbohydrate plus protein does not enhance performance during endurance exercise: a randomized cross-over placebo-controlled clinical trial.

Introduction: Protein (PRO) combined with a carbohydrate (CHO) beverage may have an ergogenic effect on endurance performance. However, evidence regarding its efficacy on similar conditions to athletes’ race day is still lacking. Objective: To compare the effect of three different nutritional supplementation strategies on performance and muscle recovery in a duathlon protocol. Methods:, 13 male athletes (29.7 ± 7.7 years) participated in three simulated Olympic-distance duathlons under three different, randomly assigned, supplementation regimens: carbohydrate drink (CHO, 75 g); isocaloric CHO plus protein drink (CHO+PRO, 60.5 g CHO + 14.5 g PRO); and, placebo drink (PLA), offered during the cycling bout. Blood samples were collected before, immediately after and 24 h after each test for creatine kinase (CK) analysis. Isometric peak torque (PT) was measured before and 24 h after each condition. The primary outcome was the time to complete the last 5km running section (t5km) in a self-selected pace. Statistical differences were considered when pThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author