3 Things I Learned from the Met Cart Test

I fought the test and the test won. It always does. It’s supposed to.

I had the opportunity to perform a full battery of on-bike performance testing at Toronto’s The Cycling Gym this morning. I fasted, I drank my americano, I fed the kids and took them to daycare, then drove down to the studio ready for a sufferfest. It didn’t disappoint.

Fitness testing is rarely much fun. This particular test was not inexpensive too. So it had better be worth the dead legs and the dollars.

Now, I don’t yet have the full report. Nor can I say that I fully grasp all the data and its implications – I’m still a little brain-tired to be honest. Still, I am thoroughly impressed by the potential.

This post will be about my test results and their application. I will write follow-ups that will be more relevant for others. Here’s what I learned about my cycling-self after strapping on the mask and running down the battery.

The 3 Key Findings

1. My individual training ranges for endurance, tempo / sweet spot, and threshold. Mine happen to map more or less with the population mean. I’m average. You may not be.
   • Endurance is 175W-205W
   • Tempo / Sweet Spot is 245W-252W
   • Threshold is around 280W
2. I’m quite poor at combusting fat for fuel (not a surprise given my diet!). Here are the highlights.
   • My crossover point – that’s where carbs and fat contribute evenly to the production of power – is only about 145W!
   • My fat max – maximal fat utilization – occurs at 170W
   • These are very low compared with my threshold
3. My breathing turns out to be a limiter. My ability to utilize my lung capacity degrades as I hit higher watts. My body must do more with less, so to speak. This was a real eye-opener. I never considered respiration as a factor in performance – when it clearly is!

All of that is great. The physiology nerd in me is well-satisfied at that peek under the hood. The coach in me asks: ‘so what?’ What can I do with this data?

The Implications

1. The training ranges are my very own guides to where I should train to develop aerobic endurance, or muscular endurance – both very useful in racing.
2. My metabolic data can be used in the following two ways:
   • If I were racing next week, and I had a good idea of the duration of my bike split and the power required to hold the speed to get me there, I could design a very accurate fueling strategy for the event.
   • Understanding that my crossover point is quite low, I can train and eat to support raising it closer to threshold. That’s a massive win for any long course athlete!
3. Knowing that breathing is limiter opens a whole new avenue to improve performance that has heretofore gone unexploited. I don’t know much about it yet. I will share my findings as I learn about it.

There is a lot of data and implications yet to cover. I feel a little like a kid in a candy store. More soon!