We've got one trainer telling us to trash the treadmill and reach solely for the weights. And we've got RealAge saying that runners live longer than non-runners. I wasn't sold on the no-cardio concept before. Now, I'm really not sold on the weights-only mentality. But I'm a runner, which makes me a little biased. What do you think?

Hundreds of runners and non-runners were tracked for more than 20 years in one study, and it was determined that those who pound the pavement are much less likely to become disabled or die than non-runners. The difference in death rate was pretty significant -- 34 percent of non-runners died by age 70, but only 15 percent of runners did. Groups were similar in age, weight and overall health status so the thought is that running was the key to survival.

If you're a runner, I say keep on truckin'. If you're new to the sport but want to pick it up, RealAge offers some pointers for getting started. If you just can't see yourself racing to the finish line, don't forget about walking -- it has some real benefits too. And now, my friends, we want to know: Would you run if your life depended on it?