I'll admit to having slothful couch potato tendencies but I'm trying to remedy that in retirement. I do early morning walks on the beach with the dog several mornings a week. Depending on the tide, they are between 2: and 4 miles. But as haha pointed out, flat is different than hilly. I've recently started taking the stairs to my Italian class. Between the class and the parking garage that is 138 steps up. (Not that I counted, lol). I've also started riding my bike to the further grocery/produce store. Every bit helps. I want to be able to handle the trip this summer and several of the apartments we rented are 2nd floor (US 3rd) with no lift and are in July locations (eg Nice)