Marcia Beloved, 

Slowed down a lot!

Old cars make it for a few more miles on some of their cylinders. They burn oil. They leak. Their compression is not the same. With worn rings, they just cannot turbo charge.

And the same goes for old mules, oxen and fading yogis.

Nature's wear and tear.

Precisely why I asked the question! Halas, I don’t see myself in a position to give a direct critic, by deference, so the question was deemed vague.

As you mention a great opportunity for study on the subtle side. But as responded such is the fate of anything material, it deteriorates over time through a grinding wear and tear.

It is a great opportunity for yogis to get direct observations of the physical bodily capabilities over time, especially those who have like yourself been in association going years back.

Ideally, the physical aspect dwindles, as subtle side inversely increases. Hopefully that inverse proportion is the case for yogins that have benefited from the exemplary teachings.

I recall a yogin, by the name of Hrdayesh, from several years back when I lived in Chicago. He was in last phase of Multiple Sclerosis, so the body was limp, he could only speak and swallow liquid food stuff. However, as he was a demonstrably committed to his path, I learned, he continued his daily meditation, and remained serene.

The physical system can be subject to any type of decrepitude, malfunction and ultimately death. May we all progress towards a satisfactory ending, by the grace of our stellar teachers and their guidance.