I had that level of fitness for many years, until I did a startup at 40. Now I am trying to get it back at 59 thru a progressive calisthenics program. I can't e

I had that level of fitness for many years, until I did a startup at 40. Now I am trying to get it back at 59 thru a progressive calisthenics program. I can't even do ONE pull up at this point, but I am getting closer!