Many times this is the cortisol, or cortisol affect on the internal body clock hormone, melatonin, secreted by the pineal gland. Another common sleep problem experienced by athletes is waking up in the middle of the night to urinate. Well that depends. Waking up once in the middle of the night to make a bathroom run is normal if you consumed lots of water before bed and you're not dehydrated. Waking up more than once, or having to go once with no success, indicates that something is up.
High aldosterone means sodium is retained, which means that fluid is retained.
This means that you will sleep better and won't have to urinate in the middle of the night. A low aldosterone level means many trips to the can during the night. This irritation will cause you to wake up and go, but only a little bit. Then a few hours later the same thing happens all over again. That's why after a hard workout, it's very important to rehydrate yourself and cool down properly to get the lactic acid out of your system.