Your aim: You exercise regularly, and you'd like to get into (or get back into) running. An hour a week should be enough to improve your physical fitness, get you in even better shape and improve your stamina.
Running uses your cardio-vascular system, respiratory system and leg muscles a great deal, so you should take it slowly at first and built up gradually. Don't skimp on your warm-up or cool-down either.
You don't want to do too much at first, so go for 1-2 runs a week...for now!
> WEEK 1: Go for a 30-minute run and stretch down well afterwards. Don't forget to drink plenty of water.
> WEEKS 2-4: Step up to 40 minutes, 50 minutes and 60 minutes. Once you can run happily for an hour, don't run for longer but up the intensity of your run by going faster or by running on an incline.