Wednesday, 16 August, 2006

Commuting on a bike

Since July 5, I've ridden my bike to work on all but three work days, and two of those days I drove the truck to the transmission shop and rode the bike back to the office.  I'm fortunate to be only seven miles from the office (at most a 30 minute ride), to have a private shower, and to set my own hours.  I have the ideal situation for bicycle commuting.  It's surprising to me how even that short ride can clear my head in the morning and in the evening can take my mind off of whatever I was working on.

I get a little perverse enjoyment in the mornings when I turn on to Parmer Lane (about 4.5 miles from the house) and see a two-mile-long line of cars (see above) backed up behind the traffic lights while I'm zipping along on the shoulder.  Traffic has been especially dense since school started on Monday.  So dense, in fact, that if somebody left the house in a car at the same time I leave on the bicycle, I'd get to the office first.  I sat in that line of traffic almost every work day for several years.  I much prefer riding the bike.

Between the wind (prevailing winds here during the summer are usually from the south or southeast) and not being warmed up in the mornings, the fastest I've been able to make the ride to the office is about 18 MPH.  I simply can't get my myself to push very hard so soon after getting out of bed.  Besides, I don't want to be totally wasted when I get to the office.

The way home, however, is a different story.  My initial goal was to break 20 MPH for the ride home.  I managed 19.4 MPH during the first week, although my average heart rate was way too high.  With a good strong tailwind a few weeks later, I managed 19.9 MPH, and the next day I shattered that with a 20.8 MPH average over the 6.8 miles.  Today I set my new personal record--21.4 MPH, or about nineteen and a half minutes' commuting time.

Reviewing my modest performance improvement (a little under 10%) over the last month and a half, I got to thinking about diminishing returns.  If I take 30 minutes to make the ride, my average heart rate will be 55% of maximum--too slow to even count as aerobic activity.  I can easily shave 20% off that time and only increase my heart rate to about 70% of maximum, which counts as an easy aerobic workout.  But to make it in 20 minutes I have to push myself into anaerobic territory to 90% of my maximum heart rate.  I'm beat when I get home and my legs are sore the next day.  I'm now at the point where any small gain in average speed will come at a huge cost.  I'm going to shoot for 22 MPH, but I know it's going to be difficult.

That said, I'm very much enjoying the freedom to commute to work via bicycle, and will be disappointed if my situation changes and forces me back into the car.