I think the danger with balancing academic work and exercise is that it's easy to use exercise to procrastinate on writing (and vice versa). My suggestion would be to set particular times for exercise and stick to it. (Exercise classes are good for this.) And, as soon as you get into good enough shape to do so, choose high-intensity exercise, so that you burn the most calories per minute.
As for writing, when I was dissertating, I set a do-able goal and made sure I stayed consistent, no matter what. For me, it was five pages a week. That might not seem like a lot, but I did it consistently week in and week out and got it done. If I had a fit of inspiration on Monday, I got to slack off the rest of the week. If I was in a section that was a slog, I worked all seven days, on top of my day job. Different disciplines work differently, so the specifics might not apply, but the same concept of goal setting applies to both writing and losing weight.
I'm Sue, and I won't let fear hold me back.
| current weight: 168.0