A tale of 2 threshold workouts – 2007 and 2008

So this week I had a nice threshold workout, my best yet on the Powercranks. I’ve been communicating with the manufacturer of PCs, Frank Day, who thought it odd that I’d be doing this kind of intensity this time of year. I explained to him that the road race season in Texas starts early – mid January in fact. Now is definitely the time to be building up the base and moving into more intense workouts. Actually, we don’t have much of an off-season here. Road racing pretty much from January to June when road races take a break due to the incredibly hot weather. Road races pick up again in September for 2 months. But then you have crit and track season basically from April to September and the state time trials in August. When racing 10 of the 12 months, it means training year round.

With that as background, I looked back at some power files, and in particular focused on workouts around the same time in 2007 – last week of October or first week of November 2007. I wanted to see how a workout from that time on regular cranks compares to the Powercrank workout I had this past week. Both sessions were 2x20 L4 sessions. Looking at the file from 2007, it certainly looks like I used a different route as this week, but nonetheless the important aspect is the overall power profile. Similar rest periods between intervals were used.

I’ve taken the liberty of averaging the power data to smooth it out. The plots below for power represent a rolling average over 18 seconds. The blue curve marked P1 is from late October 2007 on regular cranks. The pink one labeled P2 is from early November 2008 on Powercranks. The first Powercrank interval got a little buggered up 18 minutes in due to a schoolbus interfering with the interval. Both intervals are pretty darn close to each other.

You can tell these 2 rides are awfully similar when you look at the average and normalized powers for the intervals. The table below shows that the intervals on regular and Powercranks were virtually the same. The first interval had the same average power, and the normalized power is just 3 W off, about 1% different. Same for the second intervals, and those both saw about a 3-4% drop off from the first. The most striking data is the cadence. I didn’t realize just how low the cadence was dropping on the PCs.

The thing to really take out of this is how you can train the higher workout levels with Powercranks. There was no degradation in quality of the session based strictly on the data.