I have or did have that booklet published by of all places the Canadian Air Force which had their calisthenics exercise program that keeps those guys fit..
REPS is what its all about.
squat thrusts, jumping jacks, bending over to touch your toes, and of course sit ups and push ups.
This here will git ya looking like me with muscles well defined and that look that says if ya mess with me I will eat you for a snack.. lol!!!!
I don't know if I still have that but I will look for it.
Too old to care much about the exercises anymore mainly because I am so ate up with Arthur Itis in all my joints and lumbar spine that I can't do that stuff anymore and I had to give up playing golf as well.
So I have a 2 grand set of clubs and Woods I am giving to my grandson in Virginia to use. He should like the way they feel a whole lot better than tat junk his dad bought to learn with. Everything is perfectly weighted and balanced but likely would need to be adjusted for him.
Anyway, the exercises are a matter of repetition daily.
Start slow. Sets of ten or 20. Build up to doing more over time gradually.
Its a great idea to want to get in good shape. Especially get real old like Ribit! He's almost petrified. lol!!!
I'm just a spring chicken.....
Good luck with your endeavor.. Sorry I do not have that exercise book or can't find it in my organizational mess....