A while back there was an elitefts article that pointed out that risk vs activity level was a U-shaped curve. Very sedentary people have a high risk of illness and injury, and very active people have a high risk too, they just get different problems.
It's not healthy to be 5% bodyfat. It's not healthy to run a sub-3hr marathon. It's not healthy to bench press 250kg. At least not doing these things over years, anyway. It's not healthy to sit on the couch drinking beer and watching the footy for 30 years. It's not healthy to work 80 hours a week and be engaged in insider trading to get wealthy. Extremes aren't healthy... BUT some people enjoy them. I don't have a problem with someone smoking and drinking for 20 years, or pumping steroids and getting to ridiculously low bodyfat, and then dying horribly - so long as this choice was an informed choice. But too often, they get into it without realising the consequences, and by the time they know the risks they're thoroughly committed, it's too late. And that seems a pity.
The lowest risk lies in the sensible middle ground. This is why we have things like deloads in lifting, and why it's good for lifters to do some cardio, and runners to do some lifting, and the lifter to do some reading, and why it's good for all of us put some thought to our families and society in general. I've got a duty to my family to be as healthy as I can be. And to society, too - in Australia we have a public healthcare system, if I fuck myself up, everyone else has to pay for it. Things will happen, and you've got to die of something - but we can minimise the risks, I think.
