I have reduced kidney function, 50%. I retain water like crazy if I have anything salty. I must take a diuretic (water pill) to get the swelling down.
However, I have been going for 30 mile bike rides every other day. This does a good job of eliminating the need for diurectics. In fact, at times, it feels like I cannot drink another ounce. Yet I am thirsty.
I find that when I retain water, I do not drink as much on a ride. Sometimes nothing at all. And South Florida is hot!!!!
Chris