Recently I did 250 km. in a bike tour in 5 days with a group of friends for what apparently I was not enough trained. I had no problem or pain in the muscles of my legs but it seems that for my kidneys that amount of exercise was a bit too much, I got a kind of dull pain in my left kidney that is slowly slowly receding.
I had recently done kidney cleanse, so I don’t think that stones or any kind of infection is the problem. Can the kidneys be irritated only by exercising this way? I have the feeling my level of exercise have been always restricted by the kidneys, as if they were my Achilles' heel, the first thing to fail in my body.