I've exercised most of my adult life. I spend 50 minutes & 12 miles on an exercise cycle 6 days a week. I'm 73 now & my pulse is from the mid 50's to low 60's. I'd ride longer, but my *** gets sore & my feet swell up. Then I have to prop my legs up for an hour while the swelling goes down. Five years ago, I could do 70 minutes a day. I wish I could buy new parts.
On the plus side, I can buy just about anything I want within reason, but I'm such a tightwad, it takes me months to finally make a purchase.