Temperate Air Breathing Increases Cycling Performance in Hot and Humid Climate Environment

Abstract

Practicing physical activity in a hot and humid climate (HHC) is becoming increasingly common due to anthropogenic climate change and the growing number of international sports events held in warm countries. The aim of this study was to understand the physiological and psychological effects of breathing two air temperatures during cycling exercise in HHC. Ten male athletes performed two sessions of exercise in HHC (T°: 32.0 ± 0.5 °C, relative humidity: 78.6 ± 0.7%) during which they breathed hot air (HA, 33.2 ± 0.06 °C) or temperate air (TA, 22.6 ± 0.1 °C). Each session was composed of 30 min of pre-fatigue cycling at constant intensity, followed by a 10 min self-regulated performance. During pre-fatigue, TA induced a better feeling score and a lower rating of perceived effort (respectively, +0.9 ± 0.2, p < 0.05; 1.13 ± 0.21; p < 0.05) with no changes in physiological parameters. During performance, oxygen consumption and mechanical workload were increased by TA (respectively, +0.23 ± 0.1 L min−1, p < 0.05 and +19.2 ± 6.1 W, p < 0.01), whereas no significant differences were observed for psychological parameters. Reducing the breathed air temperature decreased the discomfort induced by HHC during exercise and increased the performance capacity during self-regulated exercise. Thus, breathed air temperature perception is linked to the hardship of training sessions and directly contributes to the performance decrease in HHC.

New Advances in Human Thermophysiology

“…The papers published in this Special Issue discuss the topics of greatest concern to the population and the scientific community from the perspective of human thermophysiology. Most of the articles evaluate how the physiological response during or after exercise is affected by extreme environmental conditions, such as high temperatures [ 7 ], hot and humid environments [ 8 , 9 ], dehydration status [ 10 ] or even cold environments [ 11 ]. This issue is of concern to society as a whole, since global warming is an established threat, greatly impacting our environment [ 12 ].…”

“…A novel result of these authors showed that erythrocytes may contribute to the release of glutathione during exposure to heat stress [ 10 ]. Chabert et al also showed how the temperature of the air breathed in while cycling in a hot and high humidity environment could impact physiological and perceptual responses [ 9 ]. In this sense, breathing air at 23 °C compared to 33 °C improves performance capacity and reduces discomfort [ 9 ].…”

“…Baillot et al recommended methods to decrease skin temperature or mimic cold sensations (e.g., menthol vaporization on the skin during exercise) during exercise in hot and high-humidity environments [ 8 ]. In addition, the results of Chabert et al could recommend the modification of the breathed air temperature during aerobic exercise [ 9 ]. On the other hand, adequate warm-up, hydration, training acclimatization, and clothing strategies for cycling under cold ambient conditions are recommended [ 11 ].…”

“…Chabert et al also showed how the temperature of the air breathed in while cycling in a hot and high humidity environment could impact physiological and perceptual responses [ 9 ]. In this sense, breathing air at 23 °C compared to 33 °C improves performance capacity and reduces discomfort [ 9 ]. Last but not least, a pilot study suggested that in cold environmental conditions, the running performance was reduced [ 11 ].…”