Abstract
The present study aimed to clear the effect of low-temperature carbonated water immersion on cooling rate and blood pressure following passive heating. Twelve healthy males participated in the experiment. Prior to cooling (immersion in 25 °C carbonated water or tap water), the participants were immersed in a tap water bath for 15 min to increase their body temperature. Cooling time was significantly shorter in the carbonated water session (9 ± 3 min) than in the tap water session (13 ± 4 min) (P < 0.05). The cooling rate was significantly greater in carbonated water session (0.12 ± 0.07 °C/min) than in tap water session (0.07 ± 0.03 °C/min) (P < 0.05). The mean value of the individual cooling improvement ratio was 1.92 ± 1.28. In addition, systolic blood pressure (132 ±12 mmHg vs. 126 ± 10 mmHg; P < 0.05) and mean blood pressure (97 ± 8 mmHg vs. 94 ± 6 mmHg; P < 0.05) were significantly lower in carbonated water than in tap water during cooling. These results suggest that carbonated water immersion at 25 °C cools faster than tap water immersion and that carbonated water immersion reduces the increase in blood pressure during cool water immersion.
