My goal is to eventually start jogging/running. I've started walking daily for an hour(approx 3 1/2 miles) 4-5 times a week(plus biking 4-5 days a week). I'm starting out slow because I'm over 50(53) and overweight(I use to run about 20 years-50 miles per week). Do you think returning to running/jogging is an attainable goal? Should I up my walking time and/or frequency? How long following this type of schedule before I begin to jog, maybe September?