12 minutes of activity a day is all you need to reclaim maximum health

You’re hitting the gym four to five times a week. You’re dutifully doing the elliptical trainer or treadmill for an hour at a time. But all those long, boring workouts do nothing to strengthen your heart or slim your waistline. Do enough cardio and aerobics and you’ll get old before your time.

In his new book, P.A.C.E.: The 12-Minute Fitness Revolution, Al Sears, MD, shows why the exercise rules you’ve followed for years are precisely the ones you need to ignore. Here’s why: Your lungs shrink with age, and each time you practice extended, endurance-related cardio, you’re making them even smaller and weaker.