Turning Runkeeper Cycle Logs into Watts

A good enough approximation is (10 x velocity x slope x mass) + velocity^3 / 8

velocity in metres per second (divide kmh by 3.6, divide mph by 2.25)

mass in kg (bike and rider)

slope in percent

output in watts.

Example, a 70 kg rider on a 7 kg bike doing 18 kmh up a 10% grade:

(10 x 5 x 0.1 x (70 + 7)) + 5^3 / 8 = 5 x 77 + 125 / 8 = 401 watts = 5.7 watts per kg. That's Cadel Evans territory.

In keeping with my all numbers, all the time philosophy, I decided that what I really need to be able to do is to turn a watts number. Of course, the way to bankrupt yourself correct way to do this is with a gizmo on your bike like this one:


If you want a non-wired version of something like that it'll set you back about $1,000.

So I figured, there's got to be a math way to do it. And I googled, and found this cool formula:

A good enough approximation is (10 x velocity x slope x mass) + velocity^3 / 8

velocity in metres per second (divide kmh by 3.6, divide mph by 2.25)

mass in kg (bike and rider)

slope in percent

output in watts.

Example, a 70 kg rider on a 7 kg bike doing 18 kmh up a 10% grade:

(10 x 5 x 0.1 x (70 + 7)) + 5^3 / 8 = 5 x 77 + 125 / 8 = 401 watts = 5.7 watts per kg. That's Cadel Evans territory.

Sweet. So now I just have to get from runkeeper data to this formula. Here's my most recent AWESOME ok for a beginner ride:

And then I realized that since I always bike a loop, the whole first part of that equation dissapears and we get simply velocity^3/8. Which honestly seems like a drastic oversimplification, but what the heck, let's give it a shot. 2:33 min/km needs to be converted to meteres per second for this formula, which converts to 153 seconds/km. Divide by 1000 to get .153 seconds/meter, and invert to get 6.535.

So, after this simple conversion, the internet is telling me that my power output for this ride was: (6.536^3)/8 = 35. Which is pitiful. Also, I don't believe it.

So, what's wrong? Well, for one, there's no account for resistance, size of bike, wind resistence, rolling resistance etc. So, I check out http://bikecalculator.com/wattsMetric.html. There, entering in the same numbers resulted in 97 watts for the ride, which is closer, but there again there are problems. Primarily, there is no way to indicate the elevation changes in the ride. As the runkeeper data shows, the road goes up and down significantly. The uphills suck, and the downhills rock, but do they offset each other? Not likely. But I'm out of time and space, so that will have to be the topic for another post!

Couch to 5k. Again.

This is me several months ago:

And this is me now:

Standard disclaimer about photos of me: Neither of those are actually me.

So approximately 400 years ago, the Dr. gave me the verdict that that I had torn the ligament that holds the kneecap, well, on the knee. Otherwise it just becomes a cap. Which is what I had. Fortunately, he said I'd be back to normal in a month. Now here we are, 399 years and 11 months later, and I finally ran a 5k again. At less than half the speed I was running 10k's before.

Actually, I still don't feel in shape to do it, but the above race is put on the never boring and occasionally naked Boring Runner who promised a box of prizes like his old sunglasses and used sneakers if everyone would run the race from him, and I'm like, "Hey, who wouldn't want to run a race that only exists on the internet? It will fulfill all of the stereotypes my friends have of me. And then I did. And it looked like this:

So apparently I just suck at running

First off, a picture just for my fair trading half who is always saying that she doesn't understand the absurd ratio of cars to houses on our street. This particular absurd ratio came from my bike ride this morning:

So then I went and finish my run. Here's the stats, courtesy of the new cockpit :

So not bad right? And here's the thing: I wasn't even really trying. Basically this makes me really angry at running. So basically, a really fast race is about 1:25 min/km, or roughly 80% faster than this. By comparison, the fastest 10k I have *ever* run was officially 52 mins, or about 85% faster than a really fast race. Translation? I SUCK AT RUNNING. Oy. Maybe the Pose Method will help me. I'll let you know. :)

Forget stories, give me numbers.

Timothy Ferris, author of Four Hour Body. Looking Sketchy --->

Anyone who has ever read anything by Timothy Ferris knows that it's about 1 part awesome, 2 parts horse ...stuff. That includes his recent book The Four Hour Body, which is essentially his chronicle of attempting to hack his own body. I was especially interested in his section distance events (since that's why I do). Unfortunately that turned out to be a bit on the horsey side, the experiment mentioned in the book never actually took place, instead pointing his poor readers to this page which has been coming soon since he decided that suckers like me would buy the book anyway for a while.

But, this isn't about that. This is about an actual good suggestion that he had. One of the big things to the book is that if you want to see some progress, measure EVERYTHING. As a computer completely real and legitimate scientist, this totally appeals to me. So, two years after finally getting a real job again, I went out and bought myself some real equipment. And oh my goodness, I couldn't be happier.

So when I got home, I got to plug it all in to the computer. (OK, I lied, that part is automatic too). Yes folks, I came home to this:

Now, if I understand that 4 hour body book, I'm only 3.5 hours away from winning the Kona Ironman. See you there!

My New Inspiration

As The Girl knows, I've recently become obsessed with a new video. I haven't actually said this out loud, but I think everyone realizes that I see it as a metaphor for my life. If you haven't seen it before, you totally have to check out.... The Race: