I remember, years ago, one of my cross country runners lamenting the fact that she was going to have to drive her car to her summer on East Campus and not bike the 3 miles. When I questioned her on this, she informed me there was no way she could possibly ride her bike and run all the miles I had scheduled for her that summer. "That's crazy" is what I thought, so I slowly introduced the idea back to her as "this is a way to increase your fitness". She agreed to try it and went on to have the best cross country season of her career! Did bike commuting really have something to do with it? Absolutely! It is the perfect way to add more fitness with out the pounding of running.
The important thing here is to think "training specificity" when commuting by bike. Is your emphasis on a biking event or a running event....here is what I mean......
I have learned to embrace my commuting and my running as beneficial, equally to each other. Prioritizing the event that is most important is the first thing to do. If training for a marathon/half marathon, or any running event that is your goal race, that workout should take precedent. There will be days when you will be extremely weary, leg wise, and a commute does not seem possible. Actually a slow commute is exactly what you need! Slow it down, make sure you have time so you don't have to "race" to work and get that blood flowing. Getting the body back to homeostasis is the best way to get yourself ready for the next workout. If things are feeling fine, and you've had a couple easy days of running, then making the commute more of a workout is a great way to add some strength. Emily Grace found adding miles to her commute and hill climbs. "Climbing with a heavy bag is an excellent way to build those leg muscles" Emily e-mailed me. If possible (where it is safe) "racing" your commute can add that valuable speed with out the breaking down of your muscles. I know after a long bike ride of 80-100 miles I can function, after a long run of 18-20.....not so much. So use this to your advantage. As time goes on, with your training and commuting, it gets easier and easier to do both and not be leg weary.
Now, saying that you do need to be aware of your body and listen to it. As female athletes I feel we know our bodies. My doctor used to laugh at me when I would go in and tell him " I know what's wrong with me I just need a second opinion." He understands me now and it is because I am almost always right with my diagnosis. We know when something isn't right....follow your instincts! If you have done a tough running workout - whether that be miles, or speed, or hills - and you have a long commute ahead that you will need to ride pretty quickly.....well, that may be the day you choose to drive and it's ok. Your running at this point takes precedence.
The same goes for training for a cycling event, commuting by bike should not interfere here but if you are a die hard runner as I am, it may be a bit hard to give up running workouts. Just remind yourself the commute will be more beneficial to you than getting in the extra running miles.
You just need to think "training specificity"! Train for the event, running or cycling, that is most important at the time.
One very valuable thing to remember, and I remind myself all the time with every.single.bike.commute. is .....there is way more to this commute than building fitness or getting to work..... the mental therapy I receive from my bike commutes is many time just what I need after a long week of big running miles and workouts.
Embrace the commute and use it as it needs to be used that day. Don't be afraid of the extra miles....it's actually additional fitness and that s always welcome, regardless the sport!