I was here about a year ago. Getting close to doing 5k 4 times a week, but the last 2k are more walk than run. I'm definitely more interested in getting endurance over speed, but both improve pretty steadily at this point. I guess once I'm doing 5k without walking I'll try to just increase pace. Pretty amazing how much better my quality of life is since exercising seriously for the first time in my late 40s.