I have an arthritic hip from a decades-old fall.
I have a bad curvature in my spine that makes proper posture nearly impossible.
I might have a sciatic nerve or damaged vertebrae.
I have several (including one sizable) abdominal hernias.
Walking for more than a few yards at a time becomes very painful.
Standing for longer than a few minutes at a time does as well.
There are some circuмstances surrounding these issues that can be helped, but most of these issues are chronic or nearly so.
All that said, I was spending some time at a Marian shrine recently, and was walking the Rosary Garden while praying the entire Rosary.
I spent nearly an hour and a half on my feet, and while I could certainly feel slight discomforts here and there, and while I was most certainly intentionally offering what pain I DID have to Our Lord for offenses against God and insults to Our Lady, I was by and large TOTALLY able to walk and stand for nearly 90 minutes while praying.
I then walked about a half a mile back to the parking lot, up a hill, singing hymns.
Yoga, shmoga. Leave the heathenish gyrations to the pagans and their false gods.
Fast and pray and you'll do better for your body and soul than any diet or exercise regimen could do for you.
What do people think St. Paul meant when he said, "...I buffet my body and make it my slave..."? Do they think he was doing a Richard Simmons routine? Maybe the South Beach Diet?
St. Francis called his body "Brother Ass". Like any other ass, it needed to be fed, walked and watered, but it also needed a good kick in its namesake, sometimes daily, in order that the proper lessons and obedience would be learned.
Holy saints who have modeled mortification and penance, pray for us.
Immaculate Heart of Mary, triumph soon!
Most Sacred Heart of Jesus, have mercy on us.