Author(s): MAGUIRE, K., WYDOTIS, M.M., QUESADA, P.M., JAGGERS, J.R., COCCO, A.R., DAILY, J.P., CARUSO, J.F., Institution: UNIVERSITY OF LOUISVILLE, Country: UNITED STATES, Abstract-ID: 1301

INTRODUCTION:
High-intensity interval training (HIIT) entails brief repetitive bouts of supramaximal activity separated by longer periods of active recovery. Due to its rigor, improving HIIT performance, as well as physiological function during and after such activity, is difficult. Since body heat accrues rapidly during HIIT, palm cooling may yield ergogenic and physiological benefits from greater conductive heat transfer.
METHODS:
In a randomized fashion, healthy (n = 11) women did two workouts; one with, and one without, palm cooling (PC, no PC). Workouts began as they sat quietly for ten minutes, followed by collection of the following variables: heart rate (HR), auditory canal and the hand’s palm temperatures (ACT, HT), and thermal flux (TF) from the hand’s palm. A telemetry-based watch measured HR. ACT was recorded by a handheld device (Braun; Winamac, IN). A sensor (FluxTeq; Blacksburg VA), taped to the palm of their left hands, obtained HT and TF data. After pre-exercise data collection, they did a 3-minute stationary cycling warm-up. Immediately after the warm-up and as the cycle’s braking system restricted pedal rates to 100 rpm, subjects did three 20-second supramaximal sprints. Each sprint was followed by two minutes of active recovery as subjects pedaled at 50 rpm against a 0 kg load. Per sprint, peak and average power (PP, AP) and fatigue rate (FR) were calculated. ACT, HR, HT and TF were recorded one minute after each sprint as active recovery occurred. Those same variables were measured five, ten, 20, and 30 minutes post-exercise as subjects sat quietly. For PC workouts, 10.6o C gel packs were applied to the palm halfway through the warm-up, removed once the post-exercise period began, and reapplied ten minutes post-exercise. Dependent variables were compared using 2-factor (condition, time) ANOVAs, with repeated measures per independent variable. Paired t-test served as the post-hoc, and a 0.05 a denoted significance.
RESULTS:
ACT had non-significant differences. HR elicited a time effect. HR values after each sprint were significantly higher than those collected post-exercise; in turn were significantly higher than pre-exercise values. HT had a significant two-way interaction, with no PC > PC after each sprint. Conversely, TF had a significant two-way interaction whereby PC > no PC after each sprint and ten, 20, and 30 minutes post-exercise. PP had a significant time effect (sprints 1 and 2 > sprint 3). AP also had a significant time effect (sprints 1 > sprints 2 and 3) and a trend for condition (PC > no PC). Finally, FR had a significant condition effect (no PC > PC).
CONCLUSION:
TF data show PC increased conductive heat transfer. In turn, that heat loss may be responsible for the AP trend and significant FR differences, with better values from the PC condition. Continued data collection from women is warranted to further understand PC’s effect on HIIT.