Poster Session #1: UC South Ballroom
Fuel Utilization in Response to Two Commercially Available Beverages During Exercise in the Heat
Presentation Type
Poster
Faculty Mentor’s Full Name
Charles Dumke
Abstract / Artist's Statement
INTRODUCTION: Wildland firefighters (WLFF) use sports drinks to retain fluid, and provide electrolytes and carbohydrates during long duration exercise in the heat. PURPOSE: The purpose of this study is to compare two commercially available beverages, DD (60.9 mM Na+, 3.4% CHO ) vs G (18.4 mM Na+, 5.9% CHO) on their ability to affect fat and carbohydrate metabolism during submaximal exercise in the heat. METHODS: Ten aerobically fit males (22.5± 3.9 yrs, 82.2± 10.1 kg, 53.9± 5.9 ml•kg-1•min-1 VO2 max) completed two 90-minute heat stress trials (39º C, 30% RH) walking at 50% VO2 max followed by a 30-minute rest period. Respiratory gases were collected mid (45 min) and post-exercise (90 min). At 45 minutes, subjects consumed either G or DD with volume equivalent to 150% of the weight lost. Blood glucose was measured pre- and post-exercise, and post-trial. RESULTS: Ventilation (VE) did not differ between G and DD (72.1 ± 8.4 vs. 69.4 ± 7.5 L•min-1; p=0.5). Oxygen consumption (VO2) was not different between trials (2.4 ± 0.1 vs. 2.4 ± 0.2 L·min-1; p=0.3). Carbohydrate oxidation was not significantly different between the beverages (2.1 ± 0.2 vs. 1.8 ± 0.2 g·min-1; p=0.2) for G vs. DD respectively. However, significant differences in fat oxidation and respiratory exchange ratio (RER) were found (0.38 ± 0.03 vs. 0.47 ± 0.05 g·min-1; p=0.049, and 0.89 ± 0.02 vs. 0.87 ± 0.01; p=0.04) in GG vs. DD respectively. Blood glucose was significantly greater post-trial in G vs. DD (116.0 ± 5.7 vs. 103.1 ± 3.9 mg·dL-1; p=0.01).
CONCLUSION: Following the consumption of a bolus of G (5.9% CHO) resulted in increased RER and reduced fat oxidation compared to a bolus of DD (3.4% CHO). Blood glucose was greater following ingestion of G. These data may prove critical for WLFF during work in the field.
Category
Life Sciences
Fuel Utilization in Response to Two Commercially Available Beverages During Exercise in the Heat
UC South Ballroom
INTRODUCTION: Wildland firefighters (WLFF) use sports drinks to retain fluid, and provide electrolytes and carbohydrates during long duration exercise in the heat. PURPOSE: The purpose of this study is to compare two commercially available beverages, DD (60.9 mM Na+, 3.4% CHO ) vs G (18.4 mM Na+, 5.9% CHO) on their ability to affect fat and carbohydrate metabolism during submaximal exercise in the heat. METHODS: Ten aerobically fit males (22.5± 3.9 yrs, 82.2± 10.1 kg, 53.9± 5.9 ml•kg-1•min-1 VO2 max) completed two 90-minute heat stress trials (39º C, 30% RH) walking at 50% VO2 max followed by a 30-minute rest period. Respiratory gases were collected mid (45 min) and post-exercise (90 min). At 45 minutes, subjects consumed either G or DD with volume equivalent to 150% of the weight lost. Blood glucose was measured pre- and post-exercise, and post-trial. RESULTS: Ventilation (VE) did not differ between G and DD (72.1 ± 8.4 vs. 69.4 ± 7.5 L•min-1; p=0.5). Oxygen consumption (VO2) was not different between trials (2.4 ± 0.1 vs. 2.4 ± 0.2 L·min-1; p=0.3). Carbohydrate oxidation was not significantly different between the beverages (2.1 ± 0.2 vs. 1.8 ± 0.2 g·min-1; p=0.2) for G vs. DD respectively. However, significant differences in fat oxidation and respiratory exchange ratio (RER) were found (0.38 ± 0.03 vs. 0.47 ± 0.05 g·min-1; p=0.049, and 0.89 ± 0.02 vs. 0.87 ± 0.01; p=0.04) in GG vs. DD respectively. Blood glucose was significantly greater post-trial in G vs. DD (116.0 ± 5.7 vs. 103.1 ± 3.9 mg·dL-1; p=0.01).
CONCLUSION: Following the consumption of a bolus of G (5.9% CHO) resulted in increased RER and reduced fat oxidation compared to a bolus of DD (3.4% CHO). Blood glucose was greater following ingestion of G. These data may prove critical for WLFF during work in the field.