REASON NO. 10 - TO REMOVE EXCESS WATER/ OIL FROM FOOD - DETOX!
I know this is kind of a strange reason but this was exactly what happened to me two days ago when I ran solo for 10km. It was a hard, depressing run and I had to integrate walking at the second part of the run as I just felt tired, sore, exhausted and generally down.
But I also felt that I was sweating profusely and felt sticky too. This was done at 5:00pm mind you so there was no sun out and it was a little windy. I blame all the food that I have been eating the past few days and doing no exercise. Hence, having difficulty in the run but as much as I hated said run and felt bad about it, I was glad that I took out the excess water/ oil from my body too and did a little bit of cleansing too!
Good enough to eat a lot again! Haha! Just kidding :)