Yes, excessive exercise can cause fat accumulation which happened to me in my younger years as abdominal obesity. I explained the reasons in my new book Cortisol Clarity. This stress hormone links to other metabolic hormones like insulin, leptin, and glucagon causing the effects you covered in your story.

Here is intro to my book:

https://medium.com/illumination/cortisol-clarity-the-complete-guide-to-understanding-and-managing-cortisol-361d3867269a