John !!! Yoga and SEX ??? Oh my !!! Yes ;-). Don't know about the rest of you, but wife and I are both 76 and ... 🙂
One reason I love yoga so much is that it can be a gentle meditation breathing exercise for one person but evolve into a physically demanding workout for another. If you think you're pretty fit, check out a book called simply "Yoga fitness for Men" and if you are nowhere near that then just begin with a few simple stretches. One of my favorite poses is called pigeon ... several variations are all great.