title: Effect of cold water immersion on postexercise parasympathetic reactivation.
abstract: The aim of the present study was to assess the effect of cold water immersion (CWI) on postexercise parasympathetic reactivation. Ten male cyclists (age, 29 +/- 6 yr) performed two repeated supramaximal cycling exercises (SE(1) and SE(2)) interspersed with a 20-min passive recovery period, during which they were randomly assigned to either 5 min of CWI in 14 degrees C or a control (N) condition where they sat in an environmental chamber (35.0 +/- 0.3 degrees C and 40.0 +/- 3.0% relative humidity). Rectal temperature (T(re)) and beat-to-beat heart rate (HR) were recorded continuously. The time constant of HR recovery (HRRtau) and a time (30-s) varying vagal-related HR variability (HRV) index (rMSSD(30s)) were assessed during the 6-min period immediately following exercise. Resting vagal-related HRV indexes were calculated during 3-min periods 2 min before and 3 min after SE(1) and SE(2). Results showed no effect of CWI on T(re) (P = 0.29), SE performance (P = 0.76), and HRRtau (P = 0.61). In contrast, all vagal-related HRV indexes were decreased after SE(1) (P < 0.001) and tended to decrease even further after SE(2) under N condition but not with CWI. When compared with the N condition, CWI increased HRV indexes before (P < 0.05) and rMSSD(30s) after (P < 0.05) SE(2). Our study shows that CWI can significantly restore the impaired vagal-related HRV indexes observed after supramaximal exercise. CWI may serve as a simple and effective means to accelerate parasympathetic reactivation during the immediate period following supramaximal exercise.
authors.affiliation: Research Laboratory, EA 3300 Exercise Physiology and Rehabilitation, Faculty of Sports Sciences, University of Picardie, Jules Verne, Amiens, France. martin.buchheit@u-picardie.fr
authors.forename: M
authors.initials: M
authors.lastname: Buchheit
authors.forename: J J
authors.initials: JJ
authors.lastname: Peiffer
authors.forename: C R
authors.initials: CR
authors.lastname: Abbiss
authors.forename: P B
authors.initials: PB
authors.lastname: Laursen
mesh_terms: D000328:Adult; D001642:Bicycling; D001831:Body Temperature; D003080:Cold Temperature; D006321:Heart / Q000294:innervation*; D006339:Heart Rate; D006801:Humans; D007101:Immersion; D008297:Male; D010275:Parasympathetic Nervous System / Q000502:physiology*; D005082:Physical Exertion; D020127:Recovery of Function; D013997:Time Factors; D014867:Water; D055815:Young Adult
chemical_list: D014867:Water