Suryananda, 

Question is too general. What specific area are you thinking of?

This much I can say. Just about three months ago, Yogeshwarananda, for his own information, went into the body and looked around. He was living in my body off and on for a time now. He went down into the feet on the subtle side.

His opinion was that the body was in good shape. He did not give details. 

There is no doubt that the body is deteriorating. There are many worn parts in it. Some functions just do not operate any longer. Yoga cannot reverse some defects.

In the early morning, it is a struggle to get this body moving. It feels then as if it is made of rusty metal parts. As someone who is used to old cars, this is not alarming. But even an old car has its limits. At some point one is forced to make that last drive or haul to junk yard. That much I can say about it.

It is not that the body can do what is shown in the video. The point is that this yogi still makes the effort. Yogeshwarananda some years ago was stern when he gave this instruction.

"Keep doing the practice until the very day that body is no longer responsive. You will never be a great yogi anyway. Therefore you cannot afford to retire from practice. Do not fake that you go into samadhi and does not need to do asana postures and pranayama breath infusion."