I'm 19 y/o and currently 129 pounds. I was 125 before I started running long distance with a goal of losing weight. However, since i've started running about 2 weeks ago, I have only noticed weight gain on the scale. I doubt it's from muscle because I stopped doing muscle building activities such as HIIT and toning when I started running, which means I would have lost muscle if anything. My eating habits are exactly the same as before, and I count calories while eating clean whole foods. I also fast 18 hours a day, every day. Because of this i'm having trouble believing i'm gaining weight from adding all this extra cardio.
I also drink about 72-96 oz of water per day since i've started. If these additional few pounds are from the water weight (i've heard that when starting a new exercise routine it's easy to put on water weight) why are they still there after 2 weeks and how can I get rid of them?