When most people fear exercise, it's cardio they're afraid of. They imagine running in the cold of morning or prancing around to Richard Simmons and they wince and reach for the Cheetos.
But no matter what amount of weight you can lift or how many sit-ups you can do, if you want to bring those ripped muscles and washboard abs out from under that insulating layer of fat that hides them, sooner or later you're going to have to resort to cardio.
Dave Barry once said the only rule for exercise is that it can't accomplish anything. You can, for example, drive three miles to the gym to run three miles, and that would be exercise. You cannot, however, run to the gym, because that would accomplish something.
The real goal of these types of exercise is two-fold. The first is to burn calories.
And I've got good news for those of who want to burn calories, but don't think you can keep up a cardio pace--the calorie count of what you burn is only a factor of distance. In other words, if you walk a mile or run a mile, you'll burn more or less the same number of calories. It's physics, really--it takes the same amount of energy to move a mass (in this case, your body) a certain distance.
So why do people bother to run? Well, first of all, the guy who ran burned the same number of calories faster. While it may have taken you an hour to saunter that mile, by running you could do it in 10 minutes. If you still run for the whole hour, imagine how many more calories you could burn.
The other reason is your heart. Your heart is a muscle, and just like every other organ in your body, it gets stronger if you use it and weaker if you don't. Since they haven't yet invented a pull-up machine for your heart, the only choice we're left with is trying to make it beat faster once in a while.
It's counterintuitive, I know. Every other object we encounter gets weaker with use. The more you play with it, the more likely it will break down. Our body is not this way. Exercise is the process of consistently pushing the body far enough to strain it without actually damaging it. Amazingly, this wear will cause our body to build up strength rather than break down.
With cardio, the way we set that boundary between strain and damage is with your heart rate. Based on your age, you should do cardio at 75-80% of your maximum heart rate (There are calculators for this).
What kind of exercise should you do? Well, that depends on you. Some people really dig running. I enjoyed cycling for a while. These may be too redundant for you, and you need the variety you could get from playing a sport like raquetball or basketball.
I happen to like aerobics. I really did spend this morning prancing around to Richard Simmons. It's easily self-adjusting--if it's getting difficult, you just don't prance as hard. If it's too easy--well, you know.
So get your heart rate going now. Because as tough as it is to get your heart going with cardio, it beats the alternative.