For the past few weeks I've been biking to work. It's 4.3 miles one way, so I've been doing 8.6 total each day x5days a week. So right now I'm doing over 40 miles per week.
Should my commuting miles affect how much more I ride during the day and week, if I am training for a century this fall? I'm unsure of how to "use" the miles to/from work, or if I should just ignore them alltogether.
Anyone have any suggestions? They'd be warmly welcomed!
Those 40 miles certainly count towards your base mileage for the week. How you use them depends a lot on the route. Is it broken up with frequent stops and traffic? Are there hilly sections? What's the total ride time? Could the route be lengthened to provide more benefit?
Bottom line is that they definitely count for training, and can be used. You'll need to do more than just those commutes as your century progresses, however, so look at either lengthening the commutes or supplementing them with evening rides over time.