Today's Workout - 9/9/2006

I haven't been on the bike (or done any other workouts) since last Saturday. After riding in the rain and cold... and being fully unprepared for it, I managed to catch a cold, which has finally decided to leave. So, I'm back on the bike!

Today was a L4 Computrainer bike workout aimed at improving my funtional threshold power ("FTP"). FTP is basically just a benchmark that described your average power output over a 40K time trial. My FTP has been measured (okay, guestimated) at about 275 Watts. Today's workout includes some short intervals targeted to be at or above that level. I've included the power, heart rate and cadence graphs if you're interested. Explanations to follow.

The power graph at the right shows the workout from the power output perspective. You can see that I did about 15 minutes of warm-up at an average of about 190 Watts of power. My endurance power zone (the power range at which te work being done is mostly at an aerobic effort) is from about 150 Watts to about 200 Watts. So, I was working at the upper end of the endurance zone. That's probably too high for a warm-up. The graph should show a gradual rise in power output. I started out too hard. I'll need to work on that in the future. You can see in the heart rate graph (red graph below) that my HR gradually increased to a fairly stable level. I kept my cadence (green graph below) very constant at about 90-95 rpms during the warm-up.

Following the warm-up, you can see a series of 10 short intervals. These were "spin-ups" where I raised my cadence to spin at much higher RPMs in order to work on pedaling efficiency. This is readily apparent from the cadence graph below (green) and the power graph above (yellow). I tried to spin up from about 95 rpms to 120 rpms over 30 second intervals. You can see that pedaling faster requires more effort, as the power graph spikes up. The first interval spikes more, bcause I hadn't found the proper gear in which to pedal. Since I was pedaling quickly in the original gear, the power really spiked. After the first one, I dropped into an easier gear.

After the spin-ups, I rested another 5 minutes in the endurance zone and then started the lactate threshold intervals. In the power graph (yellow) you can see that I raised my power to about 270-300 watts for about 2 minutes per interval. Cadence (green) stayed at around 90 rpms. Heart rate increased to between 170-176 bpms. Based on the power levels and the HR for these intervals, I clearly went too hard. My power levels should have averaged about 275 and certainly no more than 290. The average power of these intervals was almost 300 watts. My lactate threshold heart rate is approxomately 170 bpm. At 176 bpm, I was clearly working too hard. Cadence was good at 90-93 rpms. This feels comfortable to me, and works well.

I felt good on the first three intervals, but really felt the last two. For future workouts, I need to make sure I'm working at the proper level. This was a good learning workout. More to come later as I prepare for Ironman Wisconsin 2007.