Diet and Creatine Dose Effects on 2000 Meter Rowing Performance, Body Composition and Blood Chemistry of Division II Male College Crew Athletes

Abstract

A more rapid recycling of phosphocreatine should assist athletes during a less than 7-minute, all-out 2000 meter indoor rowing performance (2000MRP). Therefore, the purpose of this study was to examine the effects of diet and creatine monohydrate (CM) supplementation dose on 2000MRP, body composition, and the blood chemistry of 18 NCAA division II crew members during an intense 45-day competitive season. Nutritional assistance was given and intake was recorded using “fill-in” food pyramids and institutional menu forms. While the majority of their food was institutionally prepared, athletes could consume ad-libitium from any source with encouragement given to stay within individualized kilocalorie and protein intake guidelines. A mean of nine days of food records for each athlete was analyzed to yield daily values of: 3675 kcals, 18% CHON, 55% CHO and 27% FAT. CM in either 5 or 10 gram/day dose or placebo was administered to the athletes (randomized, double-blind design; 94% compliance rate) during a 45-day period. Results indicated no significant difference in nutritional intake between the three groups (kcals: p=0.94; mean macronutrients: p=0.93). Pre-test 2000MRP were obtained at the World Indoor Rowing Championships while post-test values were obtained on the team's machines. 2000MRP decreased (p<0.0001), skinfold thickness decreased (p=.001) and body mass increased (p=0.02) for all groups with no between group differences observed. No between group differences existed in blood chemistries except that aspartate transaminase (AST; p=.05) and alanine transaminase (ALT; p=0.03) values moved to significantly higher concentrations (still normal) in the 10 gram CM group compared to the placebo group. Three conclusions are warranted for division II male crew athletes during a 45-day season: (1) The administration of 5 or 10 gram/day CM doses did not significantly improve 2000MRP compared to a placebo group. (2) Pre-post body mass and skinfold thickness was not significantly improved in the CM groups compared to a placebo group. (3) AST & ALT liver enzyme concentrations in the 10 gram CM group were significantly higher compared to a placebo group.