How should I train for a century while still commuting by bike to work? I'm going to start training for a May gravel century at the end of March. This is my first century. I plan to follow this training schedule here: http://www.kintera.org/htmlcontent.asp?cid=54755. My concern is that I commute by bike to work, which is 6 miles each way. Tuesday through Friday's rides will be on a stationary at the gym over lunch, which means I'll be also riding two separate 6 mile rides on those days. On one hand I'll be putting an additional 12 miles in. On the other hand they won't be consecutive miles and will be broken into 3 different rides those days. Should I adjust the training miles to account for this, or just ignore my commute miles?
Take a "short cut".  I commonly take a "short cut" on my 10-mile commute, riding up to a neighboring community and then down a bike trail, adding another 17 miles.

Added: The advantage to this is that you're already dressed and on your bike, so the time required will be ONLY the additional time you actually spend on your bike.  Get going 90 minutes earlier in the morning or get home 90 minutes later in the PM -- no extra changing, no extra showers, no extra hauling the bike around.