So when I found myself 40, fat and weak, I paid special attention to exercise science articles, in the hopes of getting strong. I found stories about cutting-edge studies that claimed you should do intense, brief workouts instead of long ones.
I hired personal trainers certified by the National Academy of Sports Medicine in a training methodology “founded on scientific, evidence-based research.” They taught me to avoid cave man barbell lifts like squats in favor of tricky new exercises on wobble boards and big inflatable balls to stimulate my body’s core.
I learned about the science of muscle confusion — central to infomercial workouts like P90X, from beachbody.com. It’s a little hard to understand, but the idea seems to be that you change routines constantly, so that your muscles continue to adapt.
Read More: http://www.nytimes.com/2014/05/25/opinion/sunday/fitness-crazed.html