Ask yourself a couple of questions, some of which may be difficult:

1 When was the last time you had a physical;
2)Do you get tired easily when doing other physical labor;
3)Do you get enough restful sleep;
4)Are you over weight;
5)Do you get any aerobic exercise.

I only mention this because I have had to ask myself these same questions. I am going to be 75 yrs of age (did I say 75???) and I have started to drop some pounds and get some exercise on a regular basis ... I know I feel better when I can do that ...

Good luck, whatever you do ...

BTW ... I noticed that you joined S-Z on my birthday 2 years ago ... I was just a kid of 73 then ...

Just about a week ago I was telling someone about when I worked a full time job in Manhattan NY and would play gigs on the weekend ... Fridays I would commute from work on a bus about 1 1/2 hours, get home take 20 minute 'power nap', shower get dressed and go play a gig ... Saturday I would work outside around the house for 4 - 6 hours, or play an afternoon wedding, another 'power nap' and shower, put on the tux and play a wedding or a dinner dance, and very often play another gig on Sunday ... I didn't know what the word tired was back then ...