How does increasing humidity affect physiological responses and performance? π§
In short...negatively.
Elevated Humidity Impairs Evaporative Heat Loss and Self-Paced Exercise Performance in the Heat
Study Details
This new study recruited 12 trained male cyclists to complete four 700βkJ time trials at different humidities π΄ββοΈ
1οΈβ£ Low (32.9% relative humidity)
2οΈβ£ Moderate (50.5% relative humidity)
3οΈβ£ High (69.9% relative humidity)
4οΈβ£ Very High (88.4% relative humidity)
All trials were completed at ~33Β°C π‘οΈ
Performances were also self-paced (different to many previous studies) therefore reflecting real-world practice more accurately β
Key Findings
Sweating efficiency significantly decreased with elevated humidity π
π 44% drop at High humidity
π 68% drop at Very High humidity
(both vs low humidity sweat efficiency)
Power output was similar between Low and Moderate but was significantly lower inβ¦
π Very High vs all other conditions
π High vs Low / Moderate humidities
Peak core temperature was significantly higher in Very High (39.49Β°C)β¦
β¦vs Low (38.97Β°C), Moderate (39.04Β°C) and High (39.12Β°C) π₯΅
Mean skin temperature was also significantly elevated with increasing humidity π
Conclusion
Evaporative potential and sweat efficiency are significantly reduced in humid environments leading to impaired performance π¨
π§ Targeted preparation strategies (e.g. hydration, cooling, heat acclimation)
π¦ Active during exercise strategies (e.g. sweat removal with towels, water dousing)
β¦must be employed to maintain performance in these conditions β