As a person who always hated exercising, too, I can tell you that it's just a matter of starting and then stick to it until "something" clicks and makes you crave exercise like you crave food or sleep.
If knowing what's the neurological basis that makes exercise so useful for our body, is what keeps you going, that's great. But really, any reason will do.
My reason: proving to myself that I have a stronger will strength than I used to think and believe for so many years.
When I don't exercise (for me that means also practicing Ashtanga Yoga) for like a week because of external reasons, I experienced a deep slash of depression -- real depression, like seeing everything black, totally unmotivated self-loathing and so forth.
Luckily, it's just a matter of getting a good hour of intense excercise and the day after I'm back on track. There's definitively something chemical going on there.
Thanks for the book suggestion