Mark Creaven from last summer, just found in a notebook

Mark handed this over a long time ago, just after a major illness.  The photo is from last summer, when he was barely recuperating.  He's fine now, as is this, without title:

Mark

It slowly crept up on the heart on me.
I can't remember when
I used to move so easily,
Just every now and then
A twinge a pull or maybe a tear,
A slowing down for just a while.
I still moved without a care.
But now each day brings a new pain,
A deeper more distracting thought,
A memory once held so dear now lost,
A skill once learned, now untaught.
So now the end stares me in the face.
As my spirit still tries to soar,
My body still calls to end the race.