Carbohydrate-protein Drink Fails to Reduce Muscle Damage in Division III Racing CC Skiers
Sport drinks that contain protein appear to reduce the muscle damage caused by exercise under experimental conditions; however, the effectiveness under actual race conditions is not known.
Purpose: to determine whether a sport drink containing protein consumed before/during a ski race reduces muscle soreness and/or damage as indicated by serum creatine kinase (CK).
Methods: the study received approval from the college's IRB. Subjects were recruited from the men's and women's cross country ski teams. NCAA races [mostly 10 Ks] were scheduled over two weekends; there were 16 participants (M=9, F=7) the first weekend and 14 (M=9, F=5) the second weekend. Many of the subjects use a carbohydrate-protein drink either after, or before and after skiing; however, some refuse indicating the product upsets their stomachs. Subjects were allowed to engage in their normal routine surrounding races; no attempt was made to intervene regarding the beverages selected before, during or after the races. CK was measured the day before each race weekend and 24 hours later to assess muscle damage. Surveys were completed after each race to evaluate GI distress, hunger, thirst, and soreness. Another survey was given 24 hours after each race weekend to assess delayed onset muscle soreness.
Results: Creatine kinase levels increased significantly for all skiers after each race weekend (p=0.009 and p=0.0001 respectively); but there was no difference in CK levels [means or CK change (pre-post values)] between the carbohydrate-protein drink groups and those who did not use this type of beverage. Survey results indicated there was no difference in gastro-intestinal distress, perceived exertion, post-race soreness, and 24 hour soreness between those that consume a carbohydrate-protein drink with those who did not.
Conclusion: under actual race conditions of ~10 K distances a carbohydrate-protein drink did not appear to confer any advantages or disadvantages.
Jared Sundstrom and Sarah Sorensen presenting their research at the Northland Chapter of the American College of Sports Medicine, April 1, 2011, St. Cloud, MN
|To view Poster, click on link below:|
|Research Advisor: Amy Olson, PhD, RDN, LD|