The influence of palm cooling on high-intensity interval training

Subjects (n = 45) did two high-intensity interval training (HIIT) workouts on a cycle ergometer to assess intermittent palm cooling's influence on this exercise mode. Workouts included three 20-s sprints separated by two minutes of active recovery and were done either with, or without, palm cooling (PC, no PC) in a randomized order. Dependent variable data were assessed with 2-factor ANOVAs, with repeated measures per independent variable. A Bonferroni correction (α = 0.05/6 = 0.0083) mitigated the Type I error risk based on the number of dependent variables analyzed. Significant dependent variables were assessed with pairwise comparisons to identify the source of the differences. Palm temperature (PT) and thermal flux (FLX) each had significant two-way interactions; the latter dependent variable saw PC > no PC at multiple times during and after workouts. Peak power, as an absolute (PP), and relative to body mass (PP/KG), value had significant two-way interactions, with PC > no PC for the second and third sprints as identified with pairwise comparisons. Inter-treatment PP and PP/KG differences likely benefitted from PC's significantly higher FLX values. Exercise with repetitive bursts of supramaximal activity may benefit from intermittent PC to abate body heat accrual.