The Effect of Two Carbohydrate-Elektrolyte Drinks on Gastrointestinal Complaints and Physical Performance in Rowers

Abstract

The aim of study: The aims of the studies were to evaluate the incidence of gastrointestinal (GI) complaints and blood glucose and lactate concentrations after consumption of two different electrolyte–carbohydrate beverages in rowers. Material and methods: A total of 18 male professional rowers (aged 20 ± 2.0 years, body weight: 82.6 ± 10.2 kg, height: 186.0 ± 7.3 cm, ¦O 2 max: 60.4 ± 5.0 ml/kg b.w./min) participated in a two-way randomized crossover design experiment. The exercise test was performed at 70% ¦O 2 max (2 x 25 min with a 5-minute break). During the test athletes on separate days (with a 1-week washout period) received either P” or “I” (“P” was first then “I”). The athletes consumed the test drinks as follows: twice 0.5 dm 3 of each drink, 60 min before and immediately after the exercise test, and twice 0.15 dm 3 of each drink immediately before the start of the test, and after the first 25 min of exercise (during a 5-minute break). The incidence and intensity of GI complaints during and after the exercise test were scored on a standardized questionnaire. Blood samples were collected before and after the exercise test, with glucose and lactate levels determined. Results: Significant (p<0.05) changes were observed in post-exercise blood lactate levels in athletes supplemented with both electrolyte–carbohydrate drinks (“I”: 26%, “P”: 25%). A significantly (p<0.05) higher blood glucose level was noted only when athletes received “P” (on average by 12%). The consumption of the “P” drink (“P”: 83%, 1.9 ± 0.9 points) led to a more serious gastroesophageal reflux compared to “I” (“I”: 22% 0.2 ± 0.4 points). Significant differences were observed for sweet taste in mouth (“P”: 83% and I: 28%, p<0.001) and the sensation of an overfilled stomach (“P”: 89% and “I”: 39%, p<0.01). The use of both tested carbohydrate-electrolyte drinks did not protect athletes against the occurrence of typical problems appearing after exercise (general exhaustion, muscle cramp, hand trembling, tachycardia). Conclusion: Serious discomfort in the gastrointestinal tract caused by reflux after the consumption of the “P” drink results in “I” being a more advisable drink for rowers.