We are a commune of inquiring, skeptical, politically centrist, capitalist, anglophile, traditionalist New England Yankee humans, humanoids, and animals with many interests beyond and above politics. Each of us has had a high-school education (or GED), but all had ADD so didn't pay attention very well, especially the dogs. Each one of us does "try my best to be just like I am," and none of us enjoys working for others, including for Maggie, from whom we receive neither a nickel nor a dime. Freedom from nags, cranks, government, do-gooders, control-freaks and idiots is all that we ask for.
Calisthenics are 1/3 of our General Fitness triad.
As I have not really discussed in the past, there are plenty of gray zones between the three, and few exertions are purely in one category (excepting sprints which are real cardio).
Burpees might be the ultimate calisthenic. SEALS do a lot of them. The more you can do, the better overall shape you are probably in. My personal trainer/Boss wants us to do Birthday Burpees, meaning our age in burpee reps. As they say in New York, fugettaboutit.
I do sets of ten (with the pushups) in between weights sets on weights days. Might not be ideal to do that, but it is my routine, and I like routine.
We do birthday burpees. I warn everyone when mine is coming up. Next time it will be 61, (assuming I'm still mobile).... Gym was spared this year thanks to covid.
Dang, the 'gentle ones look like they would be possible with a TNR. I've been warned that impact 'anythings' will shorten the life expectancy of this titanium and plastic knee. I'm taking good care of it, but I do come up with the question What can I do at the gym? Besides 'total gym' leg presses. This one looks like a winner. Thanks!
You may want to look into a more comprehensive strength program beyond leg presses. Here are a couple of good discussions on joint replacement and strength training to help you decide for yourself: