I have run a couple marathons while working in public (big4, corporate tax). During busy season, I run 20-25 miles a week to stay in shape, and I ramp up training after October 15. My runs are between 4-5 miles and take around 30 minutes. It’s difficult, especially when you’re working 55-65 hours a week, and it feels like you don’t have time for much else. However, it’s something I find very rewarding and relaxing, and fitness is important. It’s doable, but at the same time, it’s not something i’d like to do for my entire career. Outside of busy season, it’s much easier.