Tuesday, August 19, 2008

Tuesday Morning Time Trial

I have a great commute to work. By bicycle it's about 13¼ km (8¼ mi). The first ½ km is through a commercial zone and is followed by a few kilometers that climb up lazy false flats through quiet residential streets until reaching the Arizona Canal, along which runs a path that zips diagonally under surface streets to an exit no more than 200 meters from my office. The path literally goes under the surface streets, for there exists an underpass for pedestrians and bicyclists at most intersecting roads.

I suspect there exists no place else in the valley where I could live without sacrificing either the quality of the commute or else living within walking distance to so many amenities.

Having a commute isolated from regular rush hour traffic affords me the opportunity of extending my ride goals beyond the metaphorical Point A and Point B. Some days I train and do sprints or intervals1; some days I take my time to recover and relearn the simple childhood joy of being on a bicycle. Sometimes I focus on my technique, such as maximizing the efficiency of my stroke or body posture or I experiment with different cadences. In fact, cadence experimentation transformed me from a casual pedaler favoring a cadence of 70-80 RPM into a supple spinner favoring a quick cadence of 100-110 RPM. If bicycling is the new golf, then I liken my work commute to driving range practice, where I work at improving for the weekend showoff.

Some mornings I ride a time trial2. Time trials are great as tests but are merely okay as workouts; sprints and intervals are far superior for stressing the body. I start the clock shortly after pulling out of my apartment's driveway, and I stop the clock just before exiting the canal path. The route includes three traffic lights, all at the beginning; a left turn that is usually clear; and two stop signs; but the variance in delay caused by these various impedances is surprising small in the mornings: usually no more than fifteen seconds. Such regularity provides decent fairness across efforts. The variance is quite high in the afternoon, however, and furthermore any delays are unknowable until the last stretch through the commercial zone, so I don't do time trials on the way home.

This morning I rode a time trial, although when I first mounted the bicycle I was planning on doing intervals instead. Such incidental time trials are artifacts of the route; at the beginning my pace is determined by what is necessary to catch green lights, and this frequently culminates in a half-mile pseudo-sprint between the last two lights. The remainder until the first checkpoint, which is what I call the entrance to the canal path, 4¾ km into the ride, is slightly uphill, and I usually ride it hard as something of an extended interval, to establish a good baseline for the remainder of the ride. However, sometimes I reach the checkpoint with a really good time, and it becomes opportune to switch to a time trial.

Such is what happened today. I reached the first checkpoint at a near personal best clip, so I decided to do a time trial despite having done a time trial yesterday and clocking a personal second-best time (with wind assist) of 23:05 (34.6 kph average).

A time trial requires one to know his limitations; pushing beyond the red line can cause a mid-ride breakdown which will nullify the chance for a good time. Gears must be chosen on the basis of maximizing speed given a sustainable amount of effort. Even sips from the water bottle must be taken quickly and in concert with the route's slower stretches, such as during the approach to a stop sign. Time trials are stressful physically and mentally, but they yield a satisfyingly quantifiable result. Upon completion one knows just how well one did.

Today's time trial was brutal, especially on the last stretch where I faced a bit of a headwind, but I rode well and got lucky, making all three green lights and not spending any more time than necessary at the stop signs. I even went off-road at the right-angle turn after the Central Ave underpass to avoid an oncoming cyclist without slowing down. I was rewarded with the total effort by clocking a final time of 22:40 (35.2 kph average), a personal best without significant wind assist.

YouTube link of the day: Lance Armstrong in Stage 9 of the 2003 Tour de France showing what real off-roading on a road bike entails.

Intervals are like regular, moderated sprints. They are frequently complicated, but they all follow the same basic pattern of alternating fast with slow. For example, one interval pattern that I like is to ride a faster-than-average pace for one minute followed by a slower-than-average pace for one minute and so on.

A time trial is an individual effort by a cyclist to achieve his fastest time for a given route. All effort is made for the purpose of completing fastest; this usually entails riding at a steady level of effort sustainable just long enough to complete the route.

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