I have been doing Wellen osteo guided exercise program. It's a 12 week program - 3 days/week, 30 minutes per day. Focuses on balance and strength (core/leg/back). It starts you where you are and recognizes what equipment you have available. You also have the option of making any exercise easier or harder, which is great. It was a free perk under my Medicare medigap plan with UnitedHealthcare, otherwise only $5/month. I supplement with hiking and some cardio.