See your 200, raise you a 260

Alain posted his test results the other week. Coincidentally I went for my first test in a while, though with a different objective: given my big size I need to be efficient at using fat for the Ironman distance, so my coach and I wanted to know what's going on.

Unlike Alain I was not really interested in my VO2max, but more in my performance at lower intensities. We decided to do a test with longer steps - 5 minutes, and to forgo info about the higher intensities. And unlike Alain I did the test on my bike with the Power2Max, so that I can compare the data with what is happening on the road.

Some results:

My threshold is currently at around 380w, or 4.42w/kg, around the same what Alain is at (4.54 w/kg). But that doesn't really matter that much. I was more interested in what is happening at low intensities. The good news is that my aerobic threshold is at 260w compared to Alain's 200w - 3.02w/kg vs 2.77w/kg for Alain. To do so I need to oxidize a lot of fat, which I manage to do - up to 13.5cal of fat per minute at 230w. According to Alan this is among the highest he has seen. This is good news for the Ironman, because I maintain 50% fat burning up to 290w. So the base work has paid off and metabolically I should be good for the race.

Now for the weak points: my economy is low. The bottom graph shows that only produce 60 watts per liter of oxygen at race intensity. This is way below what pros are able to put out - apparently they produce more than 70 watts per liter of oxygen. Alain is between 65 to 70 - so he is more economical. This means I use too much energy to produce power. Not good for a long race, because it means I will run out of energy more quickly.

So what does this all mean? First of all, Alain is clearly better off because he is more economical - advantage Bibi. However, coach Alan has already identified ways of addressing this - I expect to do a lot more strength work over the next training block, which should improve my economy.

In the long run I also need to push the fat oxidization to higher power levels - that's where things will become really interesting for half Ironman and faster Ironman racing.

Another great piece of information on the journey to understanding what it takes to race this distance and how to address the weak points.