REF-1048 · Gatterer et al., 2021 · International Journal of Environmental Research and Public Health, · Paper · PubMed
Expert review of sport in the cold: the heat produced by exercise reduces the clothing needed, athletes should not overdress, and warm-up warmth should be kept with insulating clothing until the start
Overdressing itself has not been studied
Key Findings
Metabolic heat production reduces the need for protective clothing in cool (below 20 °C) and colder environments, given that core temperature is maintained.
The review recommends that athletes not overdress — accepting thermal discomfort at the start of a workout — and wear breathable, wicking clothing to limit sweating-related problems.
With decreased exercise intensity heat production falls while heat loss stays high, and hypothermia may develop.
Muscle temperature raised by the warm-up should be kept with heated or insulating clothing in the transition to the start.
The authors note that the tendency of less experienced athletes to overdress has not been studied.
Practical Application
Dress for the heat the session will produce, accept being cool for the first minutes, and keep the warm layers on until the last moment before a race start.
Say plainly that "start slightly cold" is expert advice, not a tested rule.
Limitations
Narrative and oriented to winter sport; no clothing-insulation figures. The ACSM position stand on cold (Castellani 2006, DOI 10.1249/01.mss.0000241641.75101.64) recommends individual rather than standardised clothing and uses the wind-chill index for frostbite risk only. Full text was read.