The wrong paths to longevity

Here's the new secret to living forever: Just watch TV from a treadmill for 24 hours a day.

Sound crazy? Of course it does. But you tell me what to make of the latest studies: One finds you can extend your life by three years or more with just 15 minutes of exercise a day... while the other finds that every hour of TV shortens your life by 22 minutes.

Put 'em together, and you can use one to cancel out the other.

Keep watching, keep moving, keep living -- what a life!

Obviously that's nonsense. The two studies were unrelated, but they both suffer from the same fundamental flaw.

Let's see if you can spot it.

In the first, researchers in Taiwan found that people who get just 15 minutes of exercise a day live three years longer than people who don't move at all -- with that life expectancy rising another 4 percent with each additional 15 minutes of daily punishment.

In the second, researchers in Australia found that people who watch six hours of TV a day croak five years sooner than people who watch no TV -- and used that as the basis of their +/- formula.

You're seeing the problem here, right? In both studies, the researchers made conclusions we're supposed to apply to everyone based on the most sedentary people they found -- people who are probably sick, weak, fat, and even crippled to begin with.

Who else gets literally no exercise and watches six hours of TV a day?

Here's the reality: If you want to live a long and healthy life, stop searching for the perfect 15-minute workout.

It doesn't exist. Because a furious flurry of activity at the end of the day won't make up for a sedentary lifestyle the rest of the time.

Instead, keep yourself moving throughout the day -- get off your butt as much as you can. If you can pull that off, you can feel free to kick back a little at the end of the day.

And yes, you can even watch some TV.