Gastrointestinal discomfort during intermittent high-intensity exercise: effect of carbohydrate-electrolyte beverage.
Shi X, Horn MK, Osterberg KL, Stofan JR, Zachwieja JJ, Horswill CA, Passe DH, Murray R.
This study investigated whether different beverage carbohydrate concentration and osmolality would provoke gastrointestinal (GI) discomfort duringintermittent, high-intensity exercise. Thirty-six adult and adolescent athletes were tested on separate days in a double-blind, randomized trial of 6 % and 8 % carbohydrate-electrolytes (CHO-E) beverages during four 12-min quarters (Q) of circuit training that included intermittent sprints, lateral hops, shuttle runs, and vertical jumps. GI discomfort and fatigue surveys were completed before the first Q and immediately after each Q. All ratings of GIdiscomfort were modest throughout the study. The cumulative index for GI discomfort, however, was greater for the 8 % CHO-E beverage than for the 6 % CHO-E beverage at Q3 and Q4 (P < 0.05). Averaging across all 4 quarters, the 8 % CHO-E treatment produced significantly higher mean ratings of stomach upset and side ache. In conclusion, higher CHO concentration and osmolality in an ingested beverage provokes stomach upset and side ache.