Abstract
Isomaltulose is a low glycemic and insulinemic carbohydrate available as a constituent of sports drinks. However, it remains unclear whether thermoregulatory responses (sweating and cutaneous vasodilation) after isomaltulose drink ingestion differ from those of sucrose and water during exercise in a hot environment. Ten young healthy males consumed 10% sucrose, 10% isomaltulose, or water drinks. Thirty-five minutes after ingestion, they cycled for fifteen minutes at 75% peak oxygen uptake in a hot environment (30 °C, 40% relative humidity). Sucrose ingestion induced greater blood glucose concentration and insulin secretion at the pre-exercise state, compared with isomaltulose and/or water trials, with no differences during exercise in blood glucose. Change in plasma volume did not differ between the three trials throughout the experiment, but both sucrose and isomaltulose ingestions similarly increased plasma osmolality, as compared with water (main beverage effect, p = 0.040)—a key response that potentially delays the onset of heat loss responses. However, core temperature thresholds and slopes for heat loss responses were not different between the trials during exercise. These results suggest that ingestion of isomaltulose beverages induces low glycemic and insulinemic states before exercise but does not alter thermoregulatory responses during exercise in a hot environment, compared with sucrose or water.
Highlights
Consumption of fluids containing carbohydrates and electrolytes is recommended before and during exercise in a hot environment to maintain muscle glucose metabolism and fluid balance as well as physiological function, including thermoregulatory and cardiovascular responses [1,2,3]
Isomaltulose (ISO) is a naturally occurring disaccharide composed of α-1, 6-linked glucose, and fructose, in contrast to the α-1, 2glycosidic bond found in sucrose (SUC)
The aim of this study was to investigate the effect on thermoregulatory responses of ingesting carbohydrate–electrolyte beverages containing ISO before exercise in a hot environment, compared with that of ingesting beverages containing SUC and water
Summary
Consumption of fluids containing carbohydrates and electrolytes is recommended before and during exercise in a hot environment to maintain muscle glucose metabolism and fluid balance as well as physiological function, including thermoregulatory and cardiovascular responses [1,2,3]. Conventional sports drinks contain carbohydrates such as glucose, fructose, maltodextrin, and sucrose. ISO is fully digestible, with a relatively low glycemic index (32) as compared to sucrose (65). Both are available in sports drinks [4,5]. Despite the importance for sports drink consumption in a hot environment, ISO’s influence on thermoregulatory heat loss responses, including sweating and cutaneous vasodilation during heat stress in exercise, is unknown
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: International Journal of Environmental Research and Public Health
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
