Effects Of Periodic Heat Extraction On Power, Velocity, Blood Lactate, And RPE During Bench Press

While the mechanisms underlying the cause remain unclear, periodic heat extraction using a palmar cooling (PC) device can have anaerobic performance benefits. Research shows that work volume and strength increase with repeated use of a PC device during resistance training. Generating a high power output is often important for successful sports performance. However, it is currently unknown the effect PC has on power and velocity during resistance training. PURPOSE: To determine the effects of PC on power, velocity, blood lactate, and RPE during bench press in resistance-trained individuals. METHODS: 18 resistance-trained individuals completed 3 separate sessions for the study. The 1st session consisted of a 1RM bench press testing protocol. The training protocol for the 2nd and 3rd sessions consisted of 4 sets of 5 repetitions of bench press at 80% of the participant’s 1RM with 3 minutes of rest between each set. One of the training sessions was randomly designated as the experimental (PC) condition, where participants placed their dominant hand in the PC device for the duration of each interset rest period. The other session had no intervention (NO PC). Blood lactate and RPE were recorded after each set. Dependent t-tests were conducted to determine significant differences (α = 0.05) between the PC and NO PC conditions for peak power, average power, peak velocity, average velocity, average blood lactate, and average RPE. RESULTS: Participants demonstrated significantly greater peak power across all sets in the PC condition (PC = 498.6 ± 234.3 W, NO PC = 477.8 ± 223.7 W; p = 0.03). In addition, across all sets, participants rated their perceived effort lower on a modified Borg scale during the PC condition (PC = 6.2 ± 1.1, NO PC = 6.8 ± 1.7; p = 0.05). No significant differences between conditions were revealed for average power (p = 0.13), peak velocity (p = 0.06), average velocity (p = 0.15), or average blood lactate (p = 0.5). CONCLUSION: The greater peak power demonstrated in the PC condition may translate to improved anaerobic performance as individuals could train at a higher intensity. The significantly lower RPE in the PC condition, combined with the lack of significance for blood lactate, suggest that PC may be effective by limiting central nervous system fatigue rather than by having a metabolic effect.