Starting intense exercise at age 60 vs. maintaining light, consistent exercise from age 40

A: Someone who didn't exercise in their youth, but starts gradually at age 60 and manages their physique through methods like PT (Personal Training).
B: Someone who has exercised consistently since middle age (age 40), but not intensely—for example, not running, but doing two 1-minute hangs on a pull-up bar daily and climbing about 90 flights of stairs every other day—and then gradually reduces their exercise volume in their mid-to-late 60s due to age-related degenerative arthritis, etc.
Which is better, A or B?