Last week I decided to get some physiological testing done to learn more about myself as an athlete and my body’s responses to exercise. I found that Colorado Mesa University here in Grand Junction has a well run lab and hosts a number of different kinds of tests. While a number of different tests could have been useful, I decided to go with the anaerobic threshold cycling test for a number of reasons that I’ll dive into while reviewing the results.
I arrived for my scheduled time on a Tuesday morning feeling relatively fresh. I had decided to just slot the assessment into the middle of my current Ironman build meaning I have a lot of volume on the legs currently. The assessment was performed on a Lode Ergometer starting at 210 watts and progressing up 30 watts every 3 minutes. This was to allow plenty of time for my hr and breathing to steady at each level before progressing to the next. After a quick weigh in at 167 pounds/76 kg (pretty standard for me) and a warm up, we got started!
The test itself was relatively uneventful. I strapped on the usual mask to measure gas exchange and kept pedaling along while the power occasionally increased in intensity. They would have me point to my level of RPE every few minutes which generally stayed pretty low since this is not considered a maximal test. Once I got towards the end at 360 watts, breathing had definitely picked up and I was getting more uncomfortable in the mask. But the test concluded shortly after as they had gathered everything they needed.
After having some fun chatting about sport science with the staff there and cooling down, I was on my way and received the complete results a couple days later. (disclaimer: I have no degrees in exercise physiology and everything I have typed below is my understanding of the science)
There’s a lot of good actionable data here that I definitely enjoy geeking out over. One of the most straightforward takeaways is finding where a couple of key thresholds for me are. The first ventilatory threshold was found when I hit the step at 330 watts and around 161 bpm, which is about what I expected. This is where breathing becomes more labored and lactate begins accumulating in the blood. The next level determined was the second ventilatory threshold which they estimated to be about 372 watts. While I just barley got to this point in the testing, it is considered to be when breathing becomes much more intense and the production of lactate outpaces the body’s ability to clear it. Using this and the rest of the data they gathered, they were able to give me training zones based on power and hr for cycling. This will then be good takeaway information for myself and my coach Jesse Vondracek of Top Step Training to use during my day to day training.
Another interesting data point that they were able to extrapolate based on my data was my VO2 Max. While this was not a VO2 Max test, which would consist of a different protocol that would take me to the limit of my abilities to utilize oxygen as fuel, they were still able to reasonably calculate what that level may be. The max VO2 that I achieved during the test was 73.5 ml/kg/min at a power of 360 and hr of 170. Had we continued to a power of 420 using my max hr of 185 (during training a couple months prior), my projected VO2 Max would have been around 83 ml/kg/min. While VO2 Max doesn’t necessarily translate to fast race performances, a high value can be considered a pre-requisite to elite endurance performance. It is also generally considered to be based largely off genetics, with changes of up to about 20% being attributed to training. 83 ml/kg/min is definitely right up there with some of the best names out there in endurance sport, and explains a bit of my good performances despite coming into the sport later in life and maintaining a full time job. The number by itself, though, does nothing to change how I train or race, and is probably the least actionable of the data I gathered.
But before I move on, there is something more personally interesting about this VO2 Max value for me. Because this isn’t the first time I have had it tested. I have had it tested about 4 times before over the years between cycling and running. Both to be assessed for potential in the sport and as being part of research studies. The first few times I achieved values around the 68-71 ml/kg/min mark around 5-ish years ago when I was first considering myself competitive in the sport. While this is high, it is a far cry from the value of this most recent assessment. I was also tested about 2 years ago with a result of 81-82 ml/kg/min during a graded treadmill test. At the time, we thought it was a fluke, based on how drastically different it was from the tests. After all, these values are over 20% higher compared to a time when I thought I was already very well trained!
Thinking back, I can only think of 2 changes I have made in that time frame that would potentially increase my VO2 Max by that amount. Since I already a good amount of structure and quality training 5 years ago, the main change to my training has simply been volume. It’s certainly possible that increasing training volume, even in mainly aerobic work, has helped increase my VO2 Max some.
The other change was that I started working with Team Kattouf Nutrition. Since meeting Rick Kattouf, I have subscribed to using his full line of supplements focused on improving endurance performance in both training and racing. I was more hit and miss at first, but the more consistent I have been with using Team Kattouf’s nutrition products, the better my training and racing has been. And this data only solidifies my position that it actually works. I simply cannot think of any other changes I have made that would have increased my VO2 Max by this amount over the previous assessments.
The last, and likely most actionable, data I will go over is the fuel source utilization at different outputs during the test. During the test they were able to identify what amounts of carbohydrates and fats I used as a fuel source via gas exchange. This is hugely important to me with my main racing being at the Ironman distance. Having a guide to how much carbohydrates and glycogen I am using while racing will help me form a plan to be as topped off as possible starting the run. I have a finite amount of glycogen on board starting the race, and since I don’t have an iron stomach, I have to be very careful with the amount of calories I attempt to consume. It will always be optimal for me to attempt to use fat as a primary fuel source, but knowing how many carbohydrates I am burning at 240 watts versus 270 or 300 will help me make smarter decisions about pacing when it comes to certain points in the race.
That’s all for now! I am just over a month out from my first priority races of the season at Eagleman 70.3 and Ironman Cork and training has continued to go better than ever. I am excited to use everything that I am learning to it’s full extent this June and hope it makes a difference on the course!