Figure 1.
Experimental design employed in the present study.
Subjects rested for 30 min (REST) and then performed an exercise training session (EXE) composed of approximately 10 min of a resistance eccentric exercise bout (EC) and a 90 min submaximal aerobic exercise bout (AER) (two 45 min at 70% VO2max, interspersed by a 10 min passive rest, INT). The exercise training session was followed by four recovery strategies for 15 min (WI) in a randomized, crossover design: no immersion (CTRL), cold water immersion (CWI), temperate water immersion (TWI) and hot water immersion (HWI). After that, subjects recovered at room temperature for another 210 min (3 h30 min), divided in post-water immersion (POST-WI) and post-recovery (POST-REC). Heart rate variability indices were measured in the last 5 min of REST, WI, POST-WI and POST-REC.
Figure 2.
Mean heart rate (panel A) and mean rectal temperature (panel B) at rest (REST), during resistance eccentric exercise (ECC), during aerobic endurance exercise (AER) during post-exercise water immersion (WI), during post-water immersion (POST-WI), and during post-recovery period (POST-REC) for no immersion (CTRL, ο), cold water immersion (CWI, ▪), temperate water immersion (TWI, Δ) and hot water immersion (HWI, ▾).
a p<0.05 vs REST for all recovery strategies; * p<0.05 vs rest in CTRL; δ p<0.05 vs rest in TWI; Ω p<0.05 vs rest in HWI; # p<0.05 CWI vs CTRL; $ p<0.05 HWI vs CTRL. Data are shown as mean and SEM.
Figure 3.
Mean R-R (panel A), ln rMSSD (panel B), ln SD1 (panel C) and SD2 (panel D) at rest (REST), during exercise (EXE), during post-exercise water immersion (WI), during post-water immersion (POST-WI), and during post-recovery period (POST-REC) for no immersion (CTRL, ο), cold water immersion (CWI, ▪), temperate water immersion (TWI, Δ) and hot water immersion (HWI, ▾).
a p<0.05 vs REST for all recovery strategies; * p<0.05 vs rest in CTRL; δ p<0.05 vs rest in TWI; Ω p<0.05 vs rest in HWI; # p<0.05 CWI vs CTRL; $ p<0.05 HWI vs CTRL. Data are shown as mean and SEM.
Table 1.
Magnitude-based inferences during water immersion (WI), post-WI and after the recovery period (POST-REC) for ln rMSSD, mRR, SD1 and SD2 in cold WI (CWI), temperate WI (TWI) and hot WI (HWI).
Table 2.
Effect sizes (Cohen′s d) calculated by comparing water immersion strategies versus CTRL for each of the heart rate variability index and moment.