The average person excretes approx 1000-1500ml of urine when resting, accounting for well over half of our fluid loss a day.
Other losses of approx 500-650ml/day occur via ‘insensible losses’ (difficult to measure) through sweating, breathing, and approx 100ml/day lost in our faeces (on toilet).
This totals an average fluid loss of 2100-2250ml a day.
DID YOU KNOW?
High protein, low carb diets increase your total fluid loss through the osmotic effect in the digestive tract (attraction of fluid to protein/protein powders) and due to an excess build up of ammonia (waste product of protein breakdown).
Therefore combined with an exercise routine and warm weather, fluid losses could easily exceed 3000-3500ml (3-3.5L) a day, making fluid replenishment a vital part of your training regime.