Hi all. I'm just starting out as running, aiming to do a half marathon in the spring. I currently commute to work Monday to Friday on my bike, totalling about 12 miles a day. Would this be sufficient as training for running? I know it uses different muscle sets so I will be going out running on weekends (Saturday probably with Sunday off), but am not sure whether I should be cycling home, then going out for a run of an evening after that too. Any advise welcome. Maybe a half marathon is too much to start with, but i feel my general standard of fitness is pretty good.