The effect of heat acclimation on sweat microminerals: artifact of surface contamination.

Unlabelled: Heat acclimation (HA) reportedly conveys conservation in sweat micromineral concentrations when sampled from arm sweat, but time course is unknown. The observation that comprehensive cleaning of the skin surface negates sweat micromineral reductions during prolonged sweating raises the question of whether the reported HA effect is real or artifact of surface contamination.

Purpose: To measure sweat mineral concentrations serially during HA and determine if surface contamination plays a role in the reported mineral reductions.

Surface contamination artificially elevates initial sweat mineral concentrations.

Several sweat mineral element concentrations decline with serial sampling. Possible causes include reduced dermal mineral concentrations or flushing of surface contamination. The purpose of this study was to simultaneously sample mineral concentrations in transdermal fluid (TDF), sweat, and serum during extended exercise-heat stress to determine if these compartments show the same serial changes during repeat sampling.