Table 1.
Anthropometrical characteristics of subjects.
Figure 1.
Cold acclimation (CA) protocol–17 head-out cold-water immersions (CA-1 to CA-17) over 20 days.
Figure 2.
Cooling time and rectal temperature throughout the cold acclimation.
Cooling time (B) and rectal temperature before (C) and after (A) cooling. * P<0.05, compared with CA-1; # P<0.05, compared with CA-17. Values are means ± SEM.
Figure 3.
Rate of decrease in rectal temperature during cooling throughout cold acclimation.
* P<0.05, compared with CA-1. Values are means ± SEM.
Figure 4.
Skin temperature throughout cold acclimation.
Skin temperature before (A) and after (B) body cooling, and change from before to after body cooling (C). * P<0.05, compared with the CA-1. Δ Tsk = mean difference between Tsk before and Tsk after cold exposure. Values are means ± SEM.
Table 2.
Body temperature, heart rate (HR), metabolic heat production (MHP), oxygen consumption (VO2) and cold-strain index (CSI) before and after body cooling in the CA-1, CA-16 and CA-17 sessions.
Figure 5.
Body temperature gradient change before (CA-1 session) and after (CA-16 and CA-17 sessions) cold acclimation.
* P<0.05, compared with CA-1; # P<0.05, compared with CA-16. Values are means ± SEM.
Figure 6.
Heart rate (HR) throughout cold acclimation.
HR at rest and during cooling (A), and change from at rest to during cooling (B). * P<0.05, compared with CA-1. Δ HR = mean difference between HR before and HR during cold exposure. Values are means ± SEM.
Figure 7.
VO2 and metabolic heat production (MHP) throughout cold acclimation.
VO2 (A) and MHP (B). * P<0.05, compared with CA-1. Values are means ± SEM.
Figure 8.
Hyperventilation throughout cold acclimation.
* P<0.05, compared with CA-1. Values are means ± SEM.
Figure 9.
Shivering, thermal and comfort sensation throughout cold acclimation.
Shivering (A), thermal (B) and comfort (C) sensation. * P<0.05, compared with CA-1. Values are means ± SEM.
Table 3.
Blood variables before and after body cooling in CA-1, CA-16 and CA-17 sessions.
Figure 10.
Shivering sensation during the first 20(CA-1) and after cold acclimation (CA-16 and CA-17).
* P<0.05, compared with a 5 min; # P<0.05, compared with the CA-1 session; Values are means ± SEM.