Burdon, C. A., O'Connor, H. T., Gifford, J. A., Chapman, P. G., & Shirreffs, S. M. (2009). Effect of sports beverage temperature on body temperature and cycling performance in the heat. ACSM 56th Annual Meeting, Seattle, Washington, Presentation Number 2671.

This study determined the effect of a cold (4°C) or thermoneutral (37°C) sports beverage on evolution of body temperature and exercise performance in the heat and explored the influence of sensory factors to ingesting a cold stimulus (ice puree) in thermoneutral conditions. Non-acclimatised males (N = 7) were recruited to complete cold, thermoneutral, and thermoneutral + ice trials in a randomized order. Ss cycled for 90 minutes at 65% VO2peak (SSE) followed by a 15-minute time-trial in 28°C (70% RH) and ingested 3.5 ml/kg of 7.4% carbohydrate-electrolyte drink every 10 minutes including 30 ml of ice puree every five minutes in the thermoneutral + ice trial during 90-minute exercise. Rectal and skin temperatures were measured, and mean body temperature, heat storage, and total body heat content were calculated from these. Total work, distance, and average and peak power output were measured during the time-trial.

There were no differences in rectal or skin temperature between any of the conditions. For the cold and thermoneutral comparison, the changes from pre- to post-exercise in skin temperature and heat storage were lower in the cold. Total work, average power output, and distance covered in the time-trial were higher in the cold than the neutral trial. The addition of ice did not promote significant changes.

Implication. Consumption of a cold sports beverage during prolonged exercise in the heat improves body temperature measures and performance. The addition of ice does not provoke a sensory response.

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