Enhancing intermittent exercise performance through brief sole cryostimulation during breaks in a hot environment.

Area of Science:

• Exercise Physiology
• Environmental Physiology
• Thermoregulation

Background:

• Heat stress during exercise impairs performance and affects physiological responses.
• Novel cooling strategies are needed to mitigate heat strain during physical activity.
• Foot sole cryostimulation is a potential method for thermoregulation during exercise.

Purpose of the Study:

• To investigate the effects of brief sole cryostimulation on exercise performance in a hot environment.
• To assess the impact of sole cryostimulation on thermoregulation and cardiovascular function during exercise recovery.
• To evaluate changes in perceived exertion and thermal sensation with sole cryostimulation.

Main Methods:

• Eight healthy adults underwent a randomized crossover study in a 35°C, 60% RH environment.
• Participants performed intermittent cycling followed by a 10-min rest with either cryostimulation or stationary rest.
• Measurements included core/skin temperature, blood flow, cardiovascular parameters, and perceptual responses.

Main Results:

• Time to exhaustion significantly increased with sole cryostimulation (3.92 min) compared to control (3.23 min).
• Sole cryostimulation lowered skin temperature and skin forearm blood flow but did not affect core temperature or cardiovascular variables.
• Ratings of perceived exertion and thermal sensation were significantly reduced with cryostimulation.

Conclusions:

• Brief sole cryostimulation enhances exercise performance in the heat, likely by improving perceptual responses.
• This cooling method effectively reduces skin temperature and blood flow without impacting core thermoregulation or cardiovascular function.
• Sole cryostimulation represents a promising, non-invasive strategy to improve endurance in hot conditions.