This is your body. This is your body on exercise.

198 pounds

As you may remember, I started the summer in a frenzy of activity—walking, running, biking, playing tennis—but a few weeks ago, I went back to my normal routine of exercising just once a day: my one-hour walk every day with Dave.

Don't get me wrong—walking an hour a day is amazing, and I'm proud that I've done it for so many years. And I also know that it's the reason my doctors love me. But it isn't enough to lose weight. It's enough to maintain, but not to lose.

And I want to lose.

So yesterday I decided it was time to get back to two- and three-a-days. And I'm not screwing around this time or not fully committing. I walked for an hour in the morning, ran and jumped rope for 30 minutes in the evening, and ended the day by lifting weights and doing sit-ups for all thirty minutes of The Daily Show—the latter of which I plan to do from here on out. When Jon Stewart is on the television, I'll be on the floor doing leg lifts and crunches and curls.

All that exercise is great, but what's makes me even happier is how good I felt at the end of the day. I mean, I felt amaaaaaaaaaazing. Truly amazing.

And that feeling didn't stop last night. It lasted through the majority of my day today, fueling me to meet my three-a-day goal yet again. And after I finished playing a brief but rewarding fifteen minutes of basketball tonight, it hit me how quickly you can turn things around and start feeling good again.

During the weeks that I'd only been walking an hour a day, I had been starting to feel sluggish and—God forbid—fat. But thirty-six hours after re-dedicating myself to more frequent exercise throughout the day, I feel fit and energized and—my God, I know it's a cliche but—like I could do anything.

My brother-in-law always says that he feels sick if he doesn't exercise every day—an excuse, from my way of thinking, for allowing himself daily trips to the gym that my sister doesn't usually get. But the more time goes on, the more I think he's on to something.

I've known for a long time that we all feel better—or less sick, as brother-in-law says—if we work out every day, but now that I'm immersing myself so fully in exercise, I am reminded how much of a drug it is.

The more we do it, the more we want to do it, the more we need it.

I'm starting to crave biking as much as I crave cheeseburgers. I've given up planning dinner for planning my next bike route. And when I've finished my jog, I can't help but want a little more, to go a little bit further.

And this is the kind of addiction we should all want.

Two days ago I was having trouble getting motivated to do anything but the minimum sixty minutes on the walking trail. Now I'm like a junkie—jonesing for my next fix.

What a difference a day makes.