Everyone is different, i went straight into lifting weights. But thats not too common in this community. If you really want to start getting into that type of training, but dont think youre ready for weights, there are a lot of body weight exercises you can do that help get you towards those goals. Air squats are great. People at first think, they cant be that hard. But see how you feel after 100. lol. Also good old fashioned push ups are great. Whether you do the ones on your knees or not, both are great for working your arms and core. Lunges are another one.
i will say that my body would get tired but never to wear i felt like i over did it. I was very strict on getting a lot of protein tho. ive watched that video about not working out, and i get it, but there are also other doctors who will encourage lifting. I wanted to get into a good routine early on and i did. I wouldnt change a thing. I hit goal 7 months after surgery and i feel better then ever.