Intermittent face cooling reduces perceived exertion during exercise in a hot environment

Background Facial cooling (FC) is effective in improving endurance exercise performance in hot environments. In this study, we evaluated the impact of intermittent short-lasting FC on the ratings of perceived exertion (RPE) during exercise. Methods Ten healthy men performed 40 continuous minutes of ergometric cycle exercise at 65% of the peak heart rate in a climatic chamber controlled at an ambient temperature of 35 °C and a relative humidity of 50%. In the control (CONT) trial, the participants performed the exercise without FC. In two cooling trials, each participant underwent 10 s of FC at 2- (FC2) and 4-min (FC4) intervals while continuing to exercise. FC was achieved by applying two soft-gel packs (cooled to 0 °C) directly and bilaterally on the forehead, eyes, and cheeks. In another cooling trial, 10 s of FC was performed at 2-min intervals using two soft-gel packs cooled to 20 °C (FC2-20). Results The RPE values in the FC4 trial were significantly lower than those in the CONT trial at 20 min (FC4, 11.6 ± 2.2 points; CONT, 14.2 ± 1.3 points; P < 0.01). Further, significant differences in the RPE values were observed between the FC4 and CONT trials at 5–15 min and 25–40 min (P < 0.05). RPE values were also significantly lower in the FC2 trial than in the CONT trial (5–40 min). Although the RPE values in the FC2-20 trial were significantly lower (5–10 min; 15–20 min) than those in the CONT trial, there were no significant differences in the RPE between the FC2-20 and CONT trials at 25–40 min. At 35 min, the RPE values were significantly higher in the FC2-20 trial than in the FC2 trial (P < 0.05). Conclusion Intermittent short-lasting FC was associated with a decrease in RPE, with shorter intervals and lower temperatures eliciting greater attenuation of increase in the RPE.

Head, facial and neck cooling as per-cooling modalities to improve exercise performance in the heat: A narrative review and practical applications

It has been well established that athletic performance is greatly affected by environmental heat. Numerous studies have attempted to find reliable cooling strategies to improve athletic performance while exercising in the heat. Whole-body pre-cooling has been found to enhance endurance performance in both dry and humid heat. Nevertheless, positive physiological alternations induced by pre-cooling gradually disappear during exercise. Hence, there is a great need to find effective per-cooling strategies to improve athletic performance in the heat. Unfortunately, it is impractical to adopt pre-cooling approaches as a per-cooling modality to improve athletic performance due to inherent issues of practicality. Thus, a narrative review was conducted to examine the impact of head, neck and facial cooling on athletic performance in the heat. Based on current evidences, head, neck and facial cooling could greatly decrease local skin temperature at those areas where cooling was applied and thereby, local perceptual sensations were greatly enhanced. Neck cooling during exercise is found effective to improve athletic performance for both endurance and team sports athletes in the heat. Besides, neck cooling is preferred over the head, facial & combined head, facial and neck cooling for both endurance and team sport athletes in the heat from a practical application viewpoint. Research is lacking on the systematically selection of per-cooling modalities to improve athletic performance based on environmental conditions and nature of the sports activity. In addition, powerful but portable head, neck and facial cooling systems are urgently required to help athletes improving performance in the heat.

Cold Face Test-Induced Increases in Heart Rate Variability Are Abolished by Engagement in a Social Cognition Task

The vagus nerve is a major constituent in the bidirectional relationship between the heart and the prefrontal cortex. This study investigated the role of the vagus in social cognition using the cold face test (facial cooling) to stimulate the vagus nerve and increase prefrontal inhibitory control. Heart Rate Variability (HRV) was measured to index parasympathetic outflow while social cognition ability was tested using the Reading the Mind in the Eyes Test (RMET). Healthy males (n = 25) completed the RMET under two conditions: with and without facial cooling. Results indicated that although facial cooling increased HRV at rest, there was no improvement in the RMET during the facial cooling condition. Interestingly, completing the RMET with facial cooling abolished this increase in HRV, suggesting interference along the vagal reflex arc. These results are consistent with the involvement of a common cortico-subcortical circuit in autonomic and cognitive processes, important for emotion recognition.