65 year old, and now with dodgy left knee…(possible 3 year wait for knee replacement)…I bought myself a set of resistance bands, and I use them 6 days per week with Sunday rest… Monday is chest-abs-pushups, Tuesday is bi’s,Tri’s, Abs and pushups, Wednesday is Back, shoulders, abs and pushups, Then I repeat the same for Thurs,Fri, Sat… then swap body part exercises around for the following week….I also do 6 days per week easy seated 30 min spin session on my turbo trainer in the evening (low gearing and light resistance but still enough to have me sweating) , I have Wednesday evenings off from spinning….also have my calorie intake set to 1600 cals per day (though it’s not the end of the world if I go over this or fancy a take away or a pizza)…can get a tad boring…. but I tell myself that I only get out what I am prepared to put in….