If someone continues to excessively hydrate for extended periods of time during exercise, it is possible for exercise associated hyponatremia (EAH) to occur. Working knowledge of sweat rate and volume can help avoid situations of EAH in most conditions.
EAH is a potentially deadly medical condition most commonly caused by fluid intake that greatly exceeds sweat loss, which dilutes ECF sodium levels. As a result, an influx of water into the ICF space can lead to cells in the brain stem rupturing, leading to a coma or death. Multiple factors can lead to exacerbated risk of EAH. During exercise, blood flow to the kidneys is greatly diminished, resulting in reduced clearing of the excess fluid. Some individuals over-aggressively hydrate before exercise and others are genetically predisposed to altered hormonal regulation that causes the body to produce less urine than it should. It is important to teach clients to listen to their own body’s cues to not drink in excess of natural thirst.
Compare your urine to the chart above to help establish your current hydration level. Important note: you should pee into a clear container, as urine in the towel bowl is diluted by the water and will appear more clear.
Urine colour, just like thirst or change in body mass, is great at distinguishing between extremes of recovery fluid intake but is not particularly sensitive to less contrasting levels of recovery fluid intake that would likely be experienced by clients. This may be due to the subtle differences in shading for the identifying markers in the middle of the eight-level urine colour chart.