Effects of whole-body cryotherapy duration on thermal and cardio-vascular response

• Thermal response is affected by the duration of a single-session of WBC.
• Cardio-vascular response is not affected by the duration of a single-session of WBC.
• Recommended duration for a WBC is 150 s.

Whole-body cryotherapy (WBC) is the exposure of minimally dressed participants to very cold air, either in a specially designed chamber (cryo-chamber) or cabin (cryo-cabin), for a short period of time. Practitioners are vague when it comes to recommendations on the duration of a single session. Recommended exposure for cryo-chamber is 150 s, but no empirically based recommendations are available for a cryo-cabin. Therefore the aim of this study was to examine thermal and cardio-vascular responses after 90, 120, 150 and 180 s of WBC in a cryo-cabin. Our hypothesis was that skin temperature would be significantly lower after longer exposers. Twelve male participants (age 23.9±4.2 years) completed four WBC of different durations (90, 120, 150 and 180 s) in a cryo-cabin. Thermal response, heart rate and blood pressure were measured prior, immediately after, 5 min after and 30 min after the session. Skin temperature differed significantly among different durations, except between 150 and 180 s. There was no significant difference in heart rate and blood pressure. Thermal discomfort during a single session displayed a linear increase throughout the whole session. Our results indicate that practitioners and clinicians using cryo-cabin for WBC do not need to perform sessions longer than 150 s. We have shown that longer sessions do not substantially affect thermal and cardio-vascular response, but do increase thermal discomfort.