Need info to use as fuel in a fitness discussion
 

So basically, I know this guy who is in his early 60s and is seriously fit. But he has some physical problems ranging from plateaus to injuries that can be directly linked to the way he works out, which is at the same intensity, same workouts, every singe week all year long.

I have tried to explain the concept of periodization to him, but he thinks that since he's not "training" or he's not a competitive athlete that he doesn't need an off season, and only needs to vary his workouts when they get really really easy.

So does anyone here have some good information to share, or a good source to point me toward, about why periodization is good for people who just want to be fit, not just competitive athletes with a racing season?

If he doesn't want to consider changing his workouts, there's not a lot you can do. If you want a reference, Carmichael's ultimate ride is pretty good on this.

You can always improve at any age.