I did a 181k ride today. Ride time was 6:45:33. I did almost the same route in 2009 at the exact same stage of training. Weather was similar, bike was the same, I did have an aero front wheel in 2009 though. The course was slightly different (2k longer in 2009 where I got lost a couple of times in the New Forest).
The main difference between 2009 and 2013 was that in 2009 I had ridden my bike lots and I was highly motivated. This year we have had quite a bad winter, I’ve been working long hours and family commitments (rugby, pole vaulting, etc) have taken up a lot of time that I could have been riding.
Adjusting for the distance, I was 9:27 slower this year. That’s actually better than I hoped. Power wise, I am 13 Watts down (154W v 167W). I can handle that though. Not that I have much choice. But my average HR was 141bpm v 136bpm. So it is costing me a lot more effort to get less power.
The big difference is that my power dropped big time over the 2013 ride. And my HR went up over the ride.
More importantly, at the end of the 2009 ride I could have run a marathon. I am not convinced I could have done the same today.
The graph shows:
- Blue line: my average 10 minute power. It’s all over the place because I chose a hilly route.
- A dotted blue line: This is the line of best fit of my power. In an ideal world it would be flat. But its not an ideal world.
- A red line: my average HR over 10 minutes.
- a dotted red line: This is the line of best fit of my average HR. Normally, you’d expect it to go up a bit over time with constant power.
There is a metric called power:HR decoupling. In 2009, it was 4.4%. The lower the more endurance fit I am. And 4.4% showed I was fit.
Today, it was 11.5%. That’s pretty poor. So why so poor? I could argue I didn’t eat as much (I had 5 power bars (and some chocolate when I got water) v the equivalent of 10 in 2009) but the effect of that is probably pretty close to nil. My guess at the real reason is the lack of long bike rides. I did 16 rides over 3 hours between January and the IM in May 2009. So far, this year I have done 7. Oops….