I used to, when I competed in high school, and I've kept up with stretching and cardio because my body feels like shit when I don't. Resistance training, though, I (subjectively) feel fine without, perhaps even a bit better without. I'm not overweight (BMI steady at 23), and am satisfied with my looks and strength as I am without it. Mostly, it's just seemed like a waste of time.

So, my only motivation is joint and skeletal health. Available exercise routines, however, do not seem to be designed for health, but strength, looks, athletic performance, and making money (lots of making money) for those selling stuff. I've seen people spend a lot of time getting strong, looking good, and ultimately fucking themselves up.

So now, yes, I am convinced resistance training has something to offer, but health really doesn't seem to be what most workouts are designed for (except for the overweight). There are workouts designed for power, for endurance, for hypertrophy, doing X many pullups, etc. Which are best for long term joint stability? How much training is over-training for this purpose? What is the optimal trade-off between strengthening supporting muscles, imposing wear on the joint, and risking injury? This doesn't seem to be generally addressed, except for those already well into decline.

What I have found from the later mostly seems to advise doing a wide variety of exercises, rotating different exercises into and out of ones routine, and de-emphasizing (although not altogether excluding) exercises that isolate specific muscles in favor of ones that exercise larger groups of muscles in tandem. Does this just apply to those already in decline, or does it apply to proactive exercise as well? If the later, I might guess that I could start with something like the "recommended routine" but rotate in and out different exercises, doing those that cover more muscles more often... but how often, within what parameters? Is this guess even reasonable? I have no idea. That's why I'm asking.