It can be hard if you are doing other exercise too. Just take your time and build up slowly when you can fit it in. I am on week 6 of c25k now and enjoying running again (was running up to 10 miles at a time 2 years ago). Swimming is the best alternative exercise as it's non impact but works a lot if muscles. Either way it's about enjoyment.I have tried and failed to stick to a running routine, struggling to fit it in with other exercise I do.I really enjoy running and will be trying again, I will use the run/walk method to begin with and see how I do.