I'm 77 and must be careful not to injure myself during weight training (been there, done that), so lots of reps of moderate weight rather than heavy weights. With a herniated lumbar disk, running irritates my sciatic nerve, so I haven't run in 37 years
Three times each week, I walk up a 2.2-mile hill that is ~700 feet high, so 4.4 miles round-trip, all on sidewalks. I also hike in the nearby mountains occasionally usually at least 5 miles total with over 1,000 feet altitude gain.
I usually walk ~½ mile to a gym where I do ~1 hour of weight training 3 times per week. However, during this recent Omicron spike, I haven't been going to the gym even though I'm fully vaccinated and boosted. I'll probably start going again this week.