There’s an interesting article on Yoga Journal’s website outlining how the physical yoga practice can be adapted throughout your life, from your 20s into your 60s and beyond. It discusses the kinds of adapting and changing you might want to make as you age, and also has some key postures with suggestions for modifications for different age ranges.
I think it’s a good article, but it’s a shame the pictures are all of fit flexible young things. The modifications for people in their 50s or 60s may be hard to visualise if you haven’t done them before in a class with a teacher. Still, it’s worth a read.