Friday, January 30, 2009

Training (And Playing) With Power

Well I finally broke down and bought another fancy cycling gizmo. This one doesn't generate electricity like the dynohub - in fact it measures energy output. In other words, I bought a PowerTap.

There are many choices in the PT realm, and I went with what seemed most reasonable: the PRO+ model. It ain't cheap, but I'll be sure to get lots of use at it, and shouldn't have a problem bringing the $/mi ratio to a 1:1 level (e.g., ride it more than 1,000 miles) within a few months.

Why a PowerTap?

Well it started out with my at the computer, with a debit-card burning a hole in my pocket. Should I spring for some aero wheels for the Ciocc? Those would make me faster, right?

Then I thought that perhaps I could actually improve myself, e.g. the engine. And for that, you don't need fancy wheels (well you don't really need a PT, but it makes it easier I think).

How I used to "train"

Also, a little background on my previous "training" - if you could call it that. I used to just go out for 50-70 mile rides, and just hammer away, trying to keep the intensity up. No structure really, just out pounding the pavement.

But after reading The Cyclist's Training Bible, I've come to learn what structured training looks like: intervals, hill repeats, and rest days (there's a lot more to it, but these are the basics). I'd never done any of those things before, especially "rest days," or even recovery rides. The idea of going out and not trying to go hard is alien to me, but I'm slowly getting used to it.

Is it for racing?

Not really. I've done one TT, but that's pretty much the only real race I've done. Nonetheless I'd like to do a few crits this year (like the Volunteer Park & Boat Street ones in Seattle).

But if I do decide to jump into racing, having this PT data will definitely be useful.

Is it for brevets?

I'm not counting on it, as the battery life of the Garmin 705 unit is "only" 15 hours.. Sure the PT head-unit probably would have a few more hours in it, but for something like a 600k (40 hours or less) I'm not sure the combination could last.

More importantly, the wattage data wouldn't really help you unless you were doing the brevet as a Time Trial, which is a bad idea unless you're pro. In the end, it would probably just distract you from the scenery you got out to enjoy!

The real fun (in terms of power training) starts when you analyze the ride afterwards. Then you can see where your peak zones were, when you lagged, and what you could improve next time.

Although just in case I feel the need to bring it on a brevet, I did get it laced to an Open Pro rim (sorry, Narayan!). So using it on a 200k or 300k brevet certainly isn't out of the question.. And since it's not laced to a carbon Zipp, I don't have to worry about "training" on it and having it blow up at great cost.

(It would be interesting to see the PT on the Pacer, with Honjo fenders, and a dynohub! I bet you don't see many PT's set up like that..)

That's great but... let's see some results!

Oh are there ever results. More graphs & charts than you can shake a stick at. Let's start with what some call the "e-wang" chart (e.g. a Power Profile):


Moving left to right we have:

  • 5-sec power (11.79 w/kg*) - relatively weak, in the "Untrained/non-racer" category. This would be sprinting-ability, more or less.
  • 1-min power (5.68 w/kg) - even weaker - ouch! (Although I haven't really done any 1-min intervals/tests yet, so maybe I'm better than that..)
  • 5-min power (4.03 w/kg) - a bit better than the others, surely hinting at my long-distance background. The chart shows me at a Cat 4 level! Surely something's not right there.. =]
  • Functional Threshold power (3.2 w/kg) - this one has me pegged at almost in the Cat 4 range, again hinting at my LD-background. (Although I still think I wouldn't be able to keep up with the intesity of a crit, but I hope to find out this year)
* You will notice the "w/kg" notation - this is watts/kilograms. While one may want to just brag about their high wattage numbers, your weight factors into the equation. Thus, losing a few pounds actually has the effect of bringing these numbers up!

Here's the home-screen on WKO+. It shows your wattage breakdown for the last 28 days, and just about any other datapoint you can come up with.

(edit: power zones are off)

By the way, I'm getting all these fancy graphs and data from an app called WKO+. There's a free two-week trial of it, but the cost is worth it! I love me some graphs.. and does it ever deliver - I think it puts Garmin's Training Center to shame: (here you can see it highlighting my 20min peak wattage)


A few more stats

  • After doing a "Functional Threshold" (FT) test, I set my FT at about 240 watts (90% of a 20-minute test). FT is the theorhetical amount of power you could put out for one hour, at the max exertion level.
  • My max 1-sec wattage is a whopping 918 watts! (Although from what I can tell, this isn't even as high as some cat 4/5ers).

6 comments:

brad said...

And thus we see another fine cyclist overcome by one of the two most expensive questions any cyclist can ask herself: How can I go faster?

The other is: How much does my bike weigh?

Sorry, dude. I hope you recover.

Dessa said...

Welcome to the club.
Pretty soon you'll start to count in KJ, not miles.
:-)

Robert H said...

Oh relax. We all spend our money somewhere. The guy is unmarried without kids. It isn't like he is spending the little ones college fund.

cliftongk1 said...

I spend much of my day crunching numbers and pondering data sets. I'm glad that this will be fun and helpful to you, but it would totally ruin the fun I have on my bike.

George said...

Mattm- About 600km Brevets--The 705 is your limiter. Those GPS units are made for recreational cyclists and Pro-Tour riders that ride 6 hour stages at 27 mph. Set your PT to 2 sec recording and you get 30 hours. That's 30 hours of rolling time so you have plenty of time to complete your 600km.

I just completed the San Diego 600km with 18,000 feet of gain in a Total Time of 27:20. My rolling time was much less so you will have plenty of data to record.

matt m said...

Hi George, thanks for the tips! Unfortunately, given my only 600k finishing time of 39:59, I'm thinking I might need more than 30 hours of rolling time recorded (then again, I had a lot of flats on that ride so maybe 30 is about right).

So if I were to use the 705 on 600k's I'll probably get an external power source that can recharge it along the way.

In fact I might use it on this weekend's 24-hour fleche ride, and for that I'll definitely need to recharge it somewhere along the way.