Phil Mackenzie's grandparents are 80 and 84, and are very active.Phil MackenziePhil Mackenzie is a fitness influencer whose grandparents inspired him to be fit.His grandad, 84, can do 500 push-ups, while his nanny, 80, walks for two hours a day.Creating healthy habits can help you keep active into older age.This as-told-to essay is based on a conversation with Phil Mackenzie, a 37-year-old fitness influencer from Burlington, Ontario. It has been…