Did it

Some days I have a really strong smell in my urine, and I really can pinpoint exactly where from, except that I went to the gym and exercised hard the day before.
Can't say what it smells like, just a strong potent urine smell that lasts for 1 or 2 days or so. I drink plenty of water and I don't eat crappy food, no alcohol and no smokes.
Is there something in exercising hard that releases something in the bloodstream that gets eliminated in urine?