Friday, March 13, 2009

Menlo Grand Prix power data

I managed to port Ned Harding's Golden Cheetah patch for the new Powertap raw data format over to the command line utilities I prefer using, and finally got the chance to look at the numbers from my recent rides. A comparison: the Menlo Park Grand Prix to the Wednesday Noon Ride....

click on me for PDF file
Powertap data, Menlo GP and OLH. PDF version also available.


Interesting results. First of all, I simply didn't think I could produce that sort of power this year. Average power of 271 watts is bigger than what I've managed on any of my climbs of Old La Honda so far. And average power doesn't tell the whole story: normalized power gives higher weight to power above the mean than to power below the mean. It attempts to describe an "effective power": the constant power which could be produced with comparable effort. The number for the criterium was 289 watts for close to 38 minutes. That's almost as good as my best normalized power last year (291 watts) up Old La Honda, an effort less than half as long. So perhaps that is encouraging.

Menlo Park GP finish
That's me back in 73rd place (Shaun Baesman photo)


But another message is gained by comparing the numbers to last year's Menlo Grand Prix. That race was on a simpler 4-corner course. Power numbers there were substantially less for a similar average speed: 212 watt average power and 234 watt normalized power.

So how to explain this? All I can suggest is the addition of the "S-turn" resulted in more surging on this year's race. My relatively poor pack position, near the back the whole race, meant I spent more time on the brakes, more time accelerating than the riders in the front who could get through the turns with minimal wasted energy. The moral? Ride near the front, you dummy!

The comparison with Old La Honda is also interesting. After Menlo on Sunday, I did a rather mediocre sprint workout on Tuesday. Then on Wed, I was supposed to climb in Z3, according to Coach Dan Smith. Instead I succumbed to Noon Ride Syndrome (NRS). This is quite similar to ARS, "A-Ride Syndrome". Basically it means every ride becomes a race. Two guys go out hard.... I follow until I realize I can't possibly sustain that pace, and instead settle into a 290 watt target. Not crazy, right? Basically my NP for Menlo. But I just didn't have anything in the tank, and began fading badly. I was caught by Greg McQuaid and James Porter, who were chatting effortlessly as they rode besides me. Finally Greg put in a stealth attach (keeping constant speed when the grade increases) and dropped me like a bad habit. James eventually realized I was going nowhere fast and also left me behind as well. I finally arrived at the summit in 19:49, 2:46 slower than my best time, yet ready to be airlifted to the nearest emergency care facility.

So much for "sweet spot training".

Anyway, this experience reinforced my determination to stick with the program. If Coach Dan says Z3, not Z5, he means Z3, not Z5. Higher power is better training, right? Well, of course. Except it compromises recovery, which in the long term results in less fitness acquisition. It's important to keep an eye on the long-range goal, not go for that OLH PR every time out.

3 comments:

Manley Man said...

I actually like it when coach tells me to reign it back on OLH. I've noticed many more beautiful things along that climb when I'm actually able to take it in and enjoy the surroundings.

As for power, I had a nutty power file last year at the Coyote Creek crit. I think my NP was around 400, AP near 340.

djconnel said...

In contrast to me, Mr. Manley has an excellent ride in the 1-2-3 race. Hernando called his name out multiple times...

Yeah, I agree. Sometimes it's nice to just enjoy the climb.

Manley Man said...

I was too gassed to hear the crowd response, but a few people came up to me afterwards and shared with me how the crowd gasped as I, according to Hernando, slam dunked the start/finish banner. Too funny!