Original scientific paper
Effect of water immersion temperature on heart rate variability following exercise in the heat
Hui C. Choo
; Centre for Exercise and Sports Science Research (CESSR), School of Medical and Health Sciences, Edith Cowan University, 270 Joondalup Dr, Joondalup, WA 6027, Australia
Kazunori Nosaka
; Centre for Exercise and Sports Science Research (CESSR), School of Medical and Health Sciences, Edith Cowan University, 270 Joondalup Dr, Joondalup, WA 6027, Australia
Jeremiah J. Peiffer
; School of Psychology and Exercise Science, Murdoch University, 90 South St, Murdoch, WA 6150, Australia
Mohammed Ihsan
; Athlete Health and Performance Research Centre, ASPETAR – Qatar Orthopaedic and Sports Medicine Hospital, P.O. Box 29222, Doha, Qatar
Chow C. Yeo
; Catalpult Sports, Royal One Philip, 1 Philip Street #09-00, Singapore, Singapore 048692
Chris R. Abbiss
; Centre for Exercise and Sports Science Research (CESSR), School of Medical and Health Sciences, Edith Cowan University, 270 Joondalup Dr, Joondalup, WA 6027, Australia
Abstract
This study compared the effect of passive rest (CON) and water immersion at 8.6±0.2°C (CWI9), 14.6±0.3°C (CWI15) and 35.0±0.4°C (thermoneutral water immersion [TWI]) on post-exercise heart rate variability (HRV) indices. In a climate chamber (32.8±0.4°C, 32±5% relative humidity), nine men completed 25 min of cycling at the first ventilatory threshold and repeated 30-second bouts at 90% of peak power followed by a 5-minute recovery treatment in a randomised crossover manner. All water immersion re-established the HRV indices (natural logarithm of the square root of the mean sum squared differences between RR intervals [ln rMSSD], low-frequency [lnLF] and high-frequency power densities [lnHF] and Poincaré plotderived
measures [lnSD1 and lnSD2]) to the pre-exercise levels at 60 min post immersion; however, only CWI9 accelerated parasympathetic reactivation during immersion. CWI9 increased lnLF and lnSD2 during
immersion when compared with CON (p<.05). Although CWI9 had a large positive effect size (ES>0.80) on all HRV indices during immersion when compared with CON, between-conditions differences were observed only in lnLF and lnSD2 (p=.017-.023). CWI15 had a large positive ES on ln rMSSD and lnSD1 when compared with CON (both p=.064). Sympathovagal antagonism (i.e., SD ratio<0.15) did not occur during CWI9 and CWI15. Hence, both CWI treatments are effective means of enhancing post-exercise parasympathetic reactivation, but CWI9 is likely to be more effective at increasing post-exercise cardiac vagal tone.
Keywords
autonomic cardiovascular control; cooling; recovery; hydrotherapy; vagal modulation
Hrčak ID:
192631
URI
Publication date:
31.3.2018.
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