The effect of 16-minute thermal stress and 2-minute cold water immersion on the physiological parameters of young sedentary men

The present study aimed to determine the effect of 16-minute thermal stress, followed by 2 minutes of cold water immersion, on the physiological parameters of fifty-five sedentary men (mean age 20.15±1.30 years).The participants' somatic parameters were determined before sauna, and their body mass and blood pressure were measured before and after sauna treatment. Physiological parameters were monitored during the 16-minute sauna session and 2-minute cold water immersion (CRIO) or shower. The subjects perspired 0.21-0.27 liters during the 18-minute session. Heart rate values did not differ significantly between groups during the 16-minute sauna session, but significantly (p<0.001) lower HR values were noted in the CRIO group than in the control group (68.6:105.7 and 57.5:90.7 bpm). The values of SBP and DBP did not differ significantly between groups before sauna, but were significantly (p<0.001) lower in the CRIO group after sauna (SBP – 122.0:127.3 mmHg, DBP – 89.9:76.3 mmHg). In both groups, the participants remained within the easy effort range during most of the 18-minute session (650.9 and 492.6 s). A 16-minute sauna session followed by 2 minutes of cold water immersion induces a significantly greater decrease in HR and BP (SBP and DBP) than a 16-minute sauna session followed by 30 seconds in the shower and a 90 s resting period. During cold water immersion, HR values often decrease to the bradycardia range. Keywords: Finnish sauna, cryotherapy, sedentary men, physiological parameters, somatic features, body composition.