The Comparison between Different types of Cold Fluid Ingestion towards Endurance Exercise in Hot and Humid Condition

Abstract

The rise in body core temperature associated with continuous exercise in hot and humid environments is known to possess a particularly stressful challenge to the maintenance of normal body temperature and fluid homeostasis. Recent evidence has shown that internal cooling methods, such as drinking cold fluids, are able to lower core temperature and enhance endurance performance in the heat. Pre-cooling (before exercise) and per-cooling (during exercise) methods were use, as ingesting cold fluids is easily implemented on site and provides additional benefit of hydration for athletes. Therefore, this study examines the effectiveness of pre-cooling and per-cooling methods on endurance exercise towards heart rate, rectal temperature, sweat rate, and power output of athletes ingesting different types of cold fluids. 3 female high-performance cyclists were asked to complete a 30km time trial on a cycle ergometer. The familiarisation and experimental sessions were identical, however application of fluid ingestion at 4-5°C before and during exercise differs (plain water = PW, Guava juice = GJ, isotonic drink = ID). Fluid is ingested every 15 minutes during the exercise sessions. As different athletes possess different work intensities, results showed that there is no significant difference on the effects of different types of cold fluid ingestion towards thermoregulation of the body as each fluid succeeded in enhancing athletes’ performance. Therefore, it is suggested that the consumption of any types of fluid at cold temperature could help in body thermoregulation as well as enhancing continuous exercise performance.