Preliminary study on the effect of sex on skin cooling response during whole body cryostimulation (-110 °C): Modeling and prediction of exposure durations

In order to determine the required duration of whole-body exposure to extreme cold (-110 °C) in males and females for achieving the same cold-induced response, a mathematical model of skin cooling kinetics was developed. This modeling is derived from the implementation of a new experimental cryotherapy protocol to obtain continuous skin temperature maps over time. Each 3-min whole-body cryostimulation session was divided into six incremental sessions of 30 s carried out over six consecutive days. Seventeen young, healthy subjects (8 males aged 22.6 ±3.0 years and 9 females aged 23.7 ±4.7 years) agreed to participate in this study. The smallest sex-related difference in temperature was found in the trunk area (2.93 °C after 3 min) while the greatest temperature drop was found in the lower limbs (5.92 °C after 3 min). The largest temperature variation was observed between the trunk and the lower limbs, and peaked at 2.67 °C in males and 6.99 °C in females. For both sexes, skin cooling kinetics showed a strong transient exponential type decrease followed by linear regression behavior. It appeared that for achieving the same cold-induced response, the required duration of cryostimulation is longer for males. For example, a trunk skin cooling of -12 °C could be achieved in 125s for females vs 170s for males (+36% longer); for the lower limbs, the same skin cooling magnitude could be reached after 87s for females vs 140s for males (+62% longer).

Affective response to whole-body cryotherapy: Influence of sex, body mass index, age, time of day, and past experience

OBJECTIVE

Whole-Body Cryotherapy (WBC) has seen a recent surge in popularity with patients with inflammatory conditions, athletes, and even people seeking to improve general health and quality of life. WBC treatment usually requires participation in a dozen of 3-min long sessions. But compliance is considered difficult due to possible cold-induced unpleasant sensations. Based on hedonic psychology assumptions, ratings of pleasure-displeasure experienced during a taks or activity may be important to understand individual differences in attendance.

METHODS

Two hundred fifty nine customers from two French cryocenters took the Feeling Scale immediately after their first WBC session.

RESULTS

End affect appeared to be negatively valenced (M = -1.85, SD = 1.38, 95 % confidence interval: -2.02 to -1.68). Additional statistical analyses revealed a moderating influence of past experience, in women only. Similarly, BMI was found to be negatively associated with displeasure in women, but not in men.

CONCLUSION

These findings are discussed and further research directions are suggested.