I started doing C25K in Nov. I consider myself pretty fit already but I sucked at running (jogging really). I am training for a New Years Day 5k and I'm on week 6 of the program. I can already tell the leaps and bounds improvement in my jogging fitness. I think I'm jogging about a 10 min mile. I also just downloaded the Nike run app so I can get some distance info also. C25K is an excellent app to help build up to jogging. I highly recommend it. Good luck with your running Velo!

PS. I agree that the only thing that will keep you in cycling shape is cycling so I just accept that I'll have work to do in the Spring when I get back into it more regularly.