Commuting 5 days a week at these distances would have a negative effect on your race training. It would be hard to mix in enough interval and anaerobic training into the commute. Race training involved specific efforts both hard and slow. At these distances you would be stuck in the " no mans land " of training. Too hard for recovery and or not hard enough. You would be too tired to do hard training on days off and then not have recovery time during the week. What is the purpose of the commute on the bike? Try the suggestions of adding in a car or mass transit, or reduce the frequency to 2 or 3 times a week and use the commutes as Long Slow Recovery Rides.