Why is it important to wear breathable clothing for cross-country skiing?
To avoid getting wet, wear breathable clothing that eliminates water vapour generated by perspiration.
We measure its evaporative resistance = RET
RET <6: extremely breathable, ideal for most intense physical effort
RET between 6 & 12: very breathable, suitable for moderate physical effort
RET between 12 & 20: moderately breathable, not particularly pleasant during physical effort
RET >20: not very breathable and therefore not very suitable during physical effort
RET >40: not breathable