Foot Cooling between Interval Bouts Enhances Repeated Lower Limb Power Performance: The Role of Delaying Fatigue
Wu, C. M., Ho, J. Y., Wang, W. Y., & Cai, Z. Y. (2023). Foot Cooling between Interval Bouts Enhances Repeated Lower Limb Power Performance: The Role of Delaying Fatigue. Journal of human kinetics, 86, 107–116. https://doi.org/10.5114/jhk/159623
Introduction: This study aimed to investigate whether interbout foot cooling (FC) may enhance repeated lower limb power performance and the corresponding physiological responses based on interset FC, which has been demonstrated to enhance leg-press performance.
Methods: In a repeated-measures crossover design, ten active men (aged 21.5 ± 1.5 years, exercising >3 times per week) performed four bouts of 10-s cycle ergometer sprints with interbout FC at 10°C water for 2.5 min or non-cooling (NC) with a 5-day interval.
Results: The results indicated that FC elicited higher total work (27.57 ± 5.66 kJ vs. 26.55 ± 5.76 kJ) and arousal scores than NC (p < 0.05). Furthermore, under the NC condition, participants decreased mean power (p < 0.05) with no alteration of vastus lateralis (VL) electromyography (EMG) activities after the second bout; whereas under the FC condition, participants maintained steady mean power accompanied by increased VL EMG activities in the last two bouts (p < 0.05). Jointly, participants had higher mean power ([3rd = 10.14 ± 1.15 vs. 9.37 ± 1.30; 4th = 9.79 ± 1.22 vs. 9.23 ± 1.27] W/kg) and VL EMG activities in the last two bouts under the FC than NC condition (p < 0.05). However, perceived exertion and the heart rate were comparable between the two conditions (p > 0.05).
Conclusions: In conclusion, interbout FC elicited a higher arousal level and repeated lower limb power performance, which could be explained by delaying peripheral fatigue via increasing excitatory drive and recruiting additional motor units to compensate for fatigue-related responses and power decrements.
Keywords: leg press, cold immersion power output, arousal, electromyography
In Simple Terms:
This study tested if cooling the feet between short cycling sprints could help people stay stronger. When feet were cooled, people kept more power in later sprints and used their muscles more. They didn’t feel more tired or have higher heart rates. Cooling the feet helped improve sprint power by fighting off fatigue.
Uploaded by Braeden Ostepchuk, creator of the CEU-approved course 0th Law of Physiology, co-founder of Kuhler Technologies, and inventor of Kühler.