Whereas my first incentive was very short-term, incentives #2 and #3 are a bit longer-term. Let's start with the more immediate one: have more energy.
I work an obscene amount of hours, which is exacerbated by my commute. I always have a ton of household chores to do, which inevitably take longer than they should thanks to the fact that I live in a city. Even though I always try to get at least 7 hours of sleep, I always feel drained just a few hours into my day. In fact, all I want to do right now (during my lunch break!) is nap.
It didn't used to be like this. A year ago, I went on a gym kick, biking, walking, and swimming 5 days a week for months. Not long after starting this regimen, I had lots and lots more energy: I jumped out of bed every morning, ready to take on the world, and on the weekends, I quickly finished my chores so I could go on long bike rides in the park. And then, my back gave out. (There's my old friend, pain, again.) As I recuperated, my will to go to the gym faded, along with my energy, and I was right back to square one.
Having more energy would allow me to get through each day without feeling like I've just run a marathon. It would allow me the ability to approach the things I have to do with a renewed sense of purpose and drive, and it'd also allow me to do the things I want to do since I'd actually have the energy to do them. (That's another post, though.)
There is a long-term concern here, too: that I won't have the energy to keep up with kids. I don't have any yet, and I'm not pregnant, but I want to have a child soonish, and the last thing I want to do is be gasping for breath trying to catch them during a silly game of tag. Kids have and expend a ton of energy, and I'd like to be able to keep up with my kids so that we can do all sorts of cool stuff together. Even more urgent than that, perhaps, is that I'll need the energy to provide my kids with the basics when they're little. After all, if I'm too tired to go about my day now, how will it be when I've got a baby who won't sleep longer than 32 minutes at a time?