Too busy to read?

The point is that we love to debate minutiae. When it comes to weight loss, 99.99 percent of us need to know only two things: Eat less and exercise more. Only elite athletes need to do more. But instead of accepting these simple truths and acting on them, we discuss trans fats, diet pills, and Atkins versus South Beach.

If you want to make a habit of something, the worst thing you can do is pick and choose which days of the week you do it and which ones you don't. Exercise becomes a habit when you do it every day without fail. Taking rest days between exercise days breaks up the pattern that creates habits. It also makes it too easy to say today is one of your nonexercise days, and maybe tomorrow too.

The model for success I described here looks roughly like this: Focus on your diet first and get that right so you have enough energy to want to exercise. Exercise will further improve your energy, and that in turn will make you more productive, more creative, more positive, more socially desirable, and more able to handle life's little bumps.

Exercise has two very different benefits that are hard to untangle. The exercise itself releases natural pain-relieving substances, endorphins,3 and that gives you a direct feeling of well-being. But exercise is also a mental escape from whatever was stressing you before you laced your athletic shoes. That's why I recommend forms of exercises that occupy your mind at the same time as your muscles.

Dehydrate a muscle by as little as 3 percent, for example, and it will lose 10 percent of its strength and 8 percent of its speed. Inadequate hydration also compromises concentration and coordination.

Here's what I do when I know I should exercise but I feel too tired and droopy to imagine doing a vigorous workout. Instead of doing what I feel I can't do, I do what I can do--which is put on my exercise clothes and lace my sneakers. (You might call them tennis shoes or running shoes where you live.) Central to my method is that I grant myself 100 percent permission to not exercise, even after getting suited up for it. This is important because I know I won't take the first step of donning my exercise clothes if I feel it will commit me to something that just seems impossible in my current frame of mind.

Charles Atlas's "Dynamic Tension" program was to bodybuilding: a common-sense, practical program

Once exercise becomes habitual, you won't need willpower to keep going because your body and brain will simply prefer it to being a couch spud. And your natural inclination for variety will drive you to do more stuff over time.