Tuesday, February 21, 2012

Wind makes a difference - using graphs from bike

I am not a huge graphs geek, I really do not care about all the data and I do not use it to plan my training (my coach does probably).
But I did the same ride yesterday as I did last week so I wanted to compare them. Actually, they were not entirely the same. Last week, Feb 13 I did ~2h with 3x20min faster. Yesterday, Feb 20, I did an easy ride, kepping my HR around 150.
They were the same in the fact that I took the same route, around 25k out and then back (except for 5min extra on Feb 13. I am not going into details not to make it more confusing).

Interesting thing is that I was faster yesterday. My average speed was higher. And my average watts from both rides were exactly the same, 165, but my avg HR from yesterday was lower ( 149 vs 156 on Feb 13). I find it highly interesting since I was doing those 3x20min faster on Feb 13, thus I would expect my speed and both my watts and HR be higher.

But I did 5min easy between those intervals and it seems that those have a very huge impact on my watts and speed.
Ok, maybe it is not very interesting to compare those two rides after all because they were quite different.

It was realy windy on both days and since it was out and back course it is quite interesting to look at my graphs and compare "out" and "back".

Here is Feb 13.

You can clearly see my first and second interval.
I really have no idea what that spike at around min 51 is. I know that I was turning there and could not find a good place to turn thus my recovery was longer than 5min, it was 7-8min, but that spike does not make sense, it is long and then recovery between intervals is 15+min not 7. I think that it is that stupid CPU unit doing whatever it wants to do sometimes. My ride was around 2h5min and not 2h20min so there is some extra time that CPU recorded and I am sure that it is that time between interval 1 and 2. It is probably also screwing my entire data from this ride.
But then you cannot really see my third interval. You can see the beginning but not really the end because it was so windy that my cool down was only at a slightly lower HR and power as my fast intervals. You can only see the difference between interval and c/d in cadence and speed, HR almost did not fall although power went down slightly.
(That huge fall in watts from min 120 to 130 is probably due to my lack of motivation. I wanted to be done badly! But they I re-composed myself and pedalled myself home.)

And look at interval number 1 and number 2. My power, HR and cadence are around the same. But my speed is so much lower in N2. Like 4mph lower. That's because I turned around after the second interval. Stupid wind!

Now graph from Feb 20:

I kept my HR at around 150. So there are no spikes in HR. But look at the speed and power. You see the shift at min 50? That's when I turned around. Average HR for first 50min was 147 and P 155. The averages for my way back are HR 150, P 170. Quite a difference in power, isn't it? Also my cadence dropped from 88 to 78 on my way back.
Wind really makes a huge difference. You are killing yourself (ok, P 170 is not killing yourself but you know what I mean) and you are not moving. And so does drafting. You are not kiling yourself and you are moving:)


  1. Think of headwind as a nice opportunity to increase your avg power. It's like resistance training on a bike! :)