Same here. I had to switch from doing crazy stuff to just maintaining health. Hiking really fits the spot. I still get a lot of cardio (I have hiking trails with 1000m elevation gain within 10 minutes of driving) that way. But things like running or martial arts are out of the question. I am glad that I was able to adapt to a declining body. Some people my age still do high impact stuff and constantly get injured, take lots of painkillers and get surgeries.