A few other studies have looked at fluid loss following swim workouts and data suggest water temperature and swim intensity the most influential factor. Swimming in temperatures above 30 degree Celsius at an average speed over 1 m/s resulted in a fluid loss of 1 L/hr almost triple the loss in the current study. The electrolyte loss noted in this study found minimal electrolyte, but comparable due to the volume of water lost (43 mmol/L sodium, 4 mmol/L potassium, 32 mmol/L chloride).
It’s obvious sweat loss research in swimming is scarce. From experience, I feel swimmers sweat similar volumes as other mods of exercises, but due to the measurement techniques and the inability to measure water absorption during swimming the research is lacking.