Comparing Apples to Apples

One week ago, I did a solo ride which covered 57 miles in 3:10:40. Yesterday (Saturday 4/5/08), I set out to repeat this same route- one which criss crosses itself many times and keeps me reasonably close to home- one with relentless climbing and rolling hills. I really love this ride because it zig zags across West Warwick, Coventry, Scituate and Craston.. and it's just plain challenging. One day I'll ride it with my Polar S710i and show you the profile.. Okay long story short- I did the ride today in 2:59:55 and averaged 19 miles an hour. That is not all. The really interesting thing about today's ride is that the PowerTap gives an average watt reading of 210 watts today- last week it was 211! How is this possible? How can a ride which is almost 11 minutes faster have average power that is lower? Well for one, the Powertap is known to have a margin of error that is up to 5%.. which is why there's no reason to celebrate when we up our FTP by a few watts. At any rate, the key is in the normalized power! Yes, today's normalized power was about 5 watts higher than last week. What does this mean exactly? I think it means that when I was climbing, I dug deeper and produced more watts- which is easily proven by the 11 minutes I saved completing today's ride. But, for the average watts to be a touch lower, it also means that I required more recovery in between climbs. In the end, today's ride as fully one mile an hour faster than last Saturday- 19 mph. All things considered, I'm happy to see that I had it in me to do that. When I first started out, I did not feel very strong.. but heck if I was any good at training and racing 'by feel' I wouldn't have any need for a power meter, would I?
Now for some very cool charts:

Above is last Saturday, below is yesterday- one week apart, same exact ride. As I suspected, the low end and the top end power ranges (zone 1 active recovery, and zone 5b anaerobic capacity) are both a lot higher in the second ride, the one which was completed in 11 fewer minutes. To wit, the zone 1 changed from 37 minutes to 48 minutes, and the zone 5b changed from 13 minutes to 18 minutes.. Which goes to show you that for every extra 1 minute I spent in zone 5b, I needed an extra 2 minutes in zone 1.

Another chart:

This one is called the Mean Maximal Power Curve. It plots a multitude of durations against the corresponding maximum number of watts I did. Here, I've plotted both last Saturday's ride (in yellow) and yesterday's ride (dashed). It's hard to tell by looking so let me give you the wattage differences (last week vs this week) for CP1 (340:381), CP2 (307:324), CP5 (280:272), CP10 (255:246), CP20 (237:234), CP30 (same) and CP60 (same). Here again, we can see that I drilled it harder on the climbs- none of which were over a mile- most were 1/4 to 1/2 mile rollers. Here's what I get out of this (and it really comes as no surprise): I perform better when there is a lot of variability. I can wind it up into zone 5 -repeatedly- and recover from it quickly. which also explains why I suffer and perform poorly in situations where a steady zone 4 grind is required. I do a lousy job of "time trialing" and a lousy job of being in a break, especially on a flat course. I'm working on this weakness, of course, and that means I need to get into as many breaks as possible. I need to tough it out to the end just once and break the spell.

Another interesting nugget: Last week's CP60 occured between 90 and 150 minutes. Yesterday, it was minute 1 thru 60 of my ride. Both averaged 226 watts, but normalized watts (243:252) and cadence (86:90) were higher in the 2nd ride's CP60.

Lastly, overall average cadence of both rides was exactly the same: 87. That's not something I plan, it just happens.