Ottone, V. O., de Paula, F., Aguiar, P., Fiche, P., Araujol, T., Coimbra, C. A., Magalhaes, F. C., Rocha-Vieira, E., & Amorim, F. T. (2013). Recovery using different water immersion temperatures accelerates post-exercise cardiac parasympathetic reactivation. Medicine & Science in Sports & Exercise, 45(5), Supplement abstract number 2169.

This study evaluated the effect of different water immersion temperatures on cardiac parasympathetic reactivation, measured by heart rate variability, after a session of exercise in males (N = 8). Ss participated in four randomized experimental conditions conducted in a temperate environment (20 ± 2°C and 70 ± 10% relative humidity). Each experimental session consisted of 30 minutes resting in a supine position, followed by eccentric unilateral knee extension exercise (100% of the concentric 1-RM; 3 x 10 repetitions), and 90 minutes of treadmill running at 70% of VO2peak (2 x 45 minutes, separated by 10 minutes of rest). Post-exercise recovery strategies consisted of 15 minutes of passive water immersion at 15°C, 28°C, 38°C or control (seated at room temperature but not in water), followed by 30 minutes resting in a supine position. The R-R intervals were continuously recorded using a heart rate monitor. Cardiac parasympathetic activity was evaluated using a linear method by measuring the time domain [the square root of the mean of the sum of the squares of differences between adjacent normal R-R intervals (rMSSD)] during the last 10 minutes of the initial resting period (P1), the exercise session (P2), recovery strategies (P3), and the final resting period (P4).

The rMSSD in P2 compared with P1 was reduced and was not different among conditions. During P3, rMSSD was still reduced compared to P1 regardless of the experimental condition. Comparing P4 with P1, 15°C induced higher and 28°C induced similar rMSSD, while during the control condition and 38º C rMSSD was lower.

Implication. Post-exercise water immersion at 15º C and 28º C were effective in accelerating cardiac parasympathetic reactivation.

Return to Table of Contents for this issue.