I've been jogging for a long time. For the first year, I had to force myself to do it. After that, I was surprised to find I started enjoying it, looking forward it, and missing it if I didn't do it.

I don't try very hard at it, I'm not running against time, I just jog and don't worry about it.

As for boredom, the opposite happens to me. I find I think better while jogging. I work on programming bugs while jogging, and often find solutions that eluded me while sitting at my desk. I write articles and compose presentations while jogging. It's often my most intellectually productive time of the day.