Your assertion here is that the lifespan of a healthy person and one of the unhealthy individual is the same. They are not. The healthy person has less stress,

Your assertion here is that the lifespan of a healthy person and one of the unhealthy individual is the same. They are not. The healthy person has less stress, sleeps better, has better sex, has better mood and energy and isn't spending most of his life having difficulty dealing with illnesses steaming from unhealthy habits. Additionally, the time spend exercising isn't wasted, it's quiet enjoyable thanks to the release of Endorphins. Not to mention that it helps build muscles and keeps your body in shape which makes you more attractive to the opposite sex, thus increasing the chances of finding a partner. You also get all the cognitive benefits mentioned in the article for free. To top if it off, the time commitment isn't 8 hours a day. It only requires an hour every 2 days or so (it varies depending on what you're trying to accomplish). I highly recommend it.