I don't exercise as I yet have to see data showing me that exercise will increase lifespan by longer than the time invested doing it. Add the opportunity cost of the lost time to the picture as well. Same with sleep. A couple of hours less sleep is a pretty significant increase in real and meaningful lifespan. Will sleeping 8 hours increase your lifespan by a bigger percentage? No, not really. What I definitely think is stupid is overeating and then running to the gym to "burn" the excess calories. First, exercise makes you hungry. Second, are you aware of the vomitories in the Roman Empire - this isn't much different. Every expert will tell you that nutrition is more important than exercise. To me, studies about exercise are low quality as people who work out usually watch what they eat as well. Also, it could be the lower abdominal circumference of those who work out, which is a good health predictor. Anyway, I think walking 20-30 mins a day and having sex is what is natural to us. Anything else leads to tear and wear (especially, cartilage), increased metabolism, and aerobic exercise is a significant source of reactive oxygen species, so, you really need to load up on antioxidants before such workout. The slower your metabolism is, the longer you will potentially live (extend odds of getting cancer, hitting the Hayflick limit later, etc.). Intermittent fasting as a caloric restriction regimen seems to be the best option of life extension, which means, two meals a day, even better with one (Warrior Diet). Not having to worry about snacks and eating so often also extends your meaningful lifespan. I'm sure some gym nazis will downvote me, but whatever - I've invested enough time researching different alternatives of having longer and happier life and I know what's best. The only thing I know I should be doing better is stretching. I highly recommend The Longevity Project book - it debunks a lot of myths. Good Calories, Bad Calories is also great although it has a lot of enemies especially in the face of vegetarians and vegans. I believe in it's main point as I've increased my caloric intake by hundreds of calories a day, but my weight has actually decreased. I'm not saying all that Taubes says is right, but if there's one thing I got from the book is the realization that human metabolism is oversimplified, it really is not a simple arithmetic formula with just addition and subtraction. Hormones, for example, are very important, and you can talk to people with thyroid disease (hypo or hyper function) to hear how eating less can make you gain weight and how eating more can still make you lose weight. Due to environmental toxins (including those in foods such as endocrine disruptors, antibiotics, etc.), things are getting more and more complicated. Add the fact that our gut microbiota is totally out of whack and things get ugly.