Abstract
The effect of head out water immersion on the excretion of catecholamines and serum sodium transport inhibitor (STI) was studied in healthy young women during the follicular and leuteal phases. Two way ANOVA showed that menstrual cycle had no effect on the excretion of noradrenaline (NA), dopamine (DA) or serum STI. Analysis of pooled data from follicular and leuteal phases showed that immersion caused a significant increase in sodium excretion and serum STI and a significant decrease in urinary NA excreton in healthy young women. After immersion, sodium excretion, DA excretion and serum STI decreased and NA increased