Tuesday, April 21, 2009

The Power of Power

Let me preface this blog entry with this outright admission....I'm a huge data nerd.

I spend the better part of my days analyzing numbers, figures and statistics. When I drive I am predominately silent but in my head permutations of the quickest and most efficient route are always taking place. I've always had an obsession with time, speed, distance, etc...

For the first 10 - 12 years (Sarah will say 16) of my life, my sister Sarah manipulated me into doing all sorts of things by finishing her request with a simple "I'll time you!". Of course she never really did time me, but it didn't stop me from trying to achieve a personal best time.

Part of the reason I've always loved cycling is the endless amount of data and choices from that data it provides me. Am I faster spinning at 100rpm or should I push a big gear? Am I better off saving some energy on the climb and attacking the flats?

After several years of using a Polar heart rate monitor, last winter I took the plunge and bought a PowerTap for my road bike. In conjunction with that, I took advantage of my cycling team's sponsorship by TrainingPeaks.com and picked up a copy of WKO+ for the ultimate data geek indulgence. The difference between power and heart rate is easy to see. I heard it once described as the following "Heart rate is like using an axe, where power is like using a scalpel". I've always thought that summed it up well. You can see in my workout file from tonight how the power (Yellow graph) stays relatively constant but my heart rate steadily increases.

This particular workout is much harder than I expected. Its just doing an aerobic pace, but then every 3 minutes you do a "jump" to 175% of your threshold power. Its great for about the first 20 minutes, then the jumps seem to come quickly. Hard to keep pushing hard for 20 jumps too.

Last year, I put in hard, hard hours from January to April using the power meter almost every single ride. I targeted increasing my functional threshold, and when May came and the "good stuff" started opening up in the higher terrain I was stronger than ever. For the first time since moving to CO, I was killing the climbs and recovering faster after hard efforts. I was amazed at how much better I could target my work with the power meter than with a heart rate monitor. With the hear rate monitor, I think I often thought I was working harder than I was. With the power meter, with that big wattage number staring you down all the time there is no escaping it when you aren't laying down the power you are supposed to be putting out.

Once the weather got nice, I pretty much started just riding the mountain bike(s) without any regard to power or training or data. I spent the winter preparing to be strong all summer and now I was just out reaping the rewards. I'll never be someone who follows a training plan strictly, and you won't ever catch me changing my ride or turning down hard efforts because it doesn't fit my plan. However, I did do a lot more "recovery" rides last year and I do believe it helped me last year.

So fast forward to November of 2008...

In an ill fated game of squash in San Antonio left me with a ruptured Achilles, and a derailed training plan for 2009. In what seems like a miraculous recovery, I was putting miles on my bike by the first of the year after only 6 weeks post-surgery. I'm on assignment in Calgary most weeks, so I decided to take advantage of the corporate apartment provided to me and shipped up my road bike and trainer up north.

This is where I've discovered how helpful the power meter is in not only helping me get back in shape, but also keeping me in check from going to hard too fast. I've started back slowly, doing very little threshold work until the last couple weeks but the fitness is starting to come back slowly. What is really nice is that I can quantitatively see where I am now versus where I was a year ago and target my training accordingly. Obviously I'm not doing much (any) sprint work yet, but my the rest of my numbers are improving steadily.

With power, the magic number is watts per kilogram. In other words, how much power can you produce versus how much you weigh. I'm still about 10lbs over where I need to be, but that is dropping all the time with the work as well.

Here is my best effort for a given time frame for last year compared to this year. You can see that with the exception of the sprint power (about 1/2 of last year's best), I'm not too far removed which is encouraging.

You can see that I've been doing a lot of endurance / base building and not a lot of hard efforts, but that will change soon.

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