My First CPET Test – January 2019


Well, the results are in. Am I glad that I did it?

Don’t let them tell you it won’t hurt, but then if it didn’t, it wouldn’t be giving you the information you want.

The process

The first thing Patrick does is put you at ease and talks you through the process. It is very reassuring and I will admit to being a bit nervous, just in case it did identify any issues.

We started with a spyrometry test, putting a breathing tube in my mouth, taking a really deep breath, then expelling it, fast and totally, until I couldn’t get out any more. This establishes my lung capacity, as well as the flow and efficiency.

p1050496I then get strapped up with the 12 lead ECG, the blood pressure monitor, and the breathing tube I used for my initail test is now attached to a sealed face mask, so all of my breating will now be analysed.

Wired up and with my saddle position at the right height, I then agree an expected maximum power output, from which he determines the steps in resistance over the test period.

We start the test and I try to maintain 85 RPM, and as this is the only data I can see during the entire test, there are no distractions. All I have to do is maintain that.

The Test

p1050492During the test, I focus on this number “85” and try to keep it rolling, letting my breating do what it needs to do in order to maintain this. It is not a natural feeling as you are breating through the small tube, so I pick a point in the room and ignore everything, just keep pushing.

After seven minutes I reach my Anaerobic Threshold (AT) at which point my body moves from burning 28% Fat/72% Carbohydrates to a 6%/94% split. This is a significant point as this is my Extensive zone, and for the type of riding I do, long days in the saddle, long climbs, this zone is key to my survival zone.

p1050499After a further two minutes I reach my respiratory compensation point – RCP, the point at which I start to run on 100% Carbohydrates, normally seen as the Intensive training zone, so only a matter of time now until I run out of steam and I start to feel the bite.

Sure enough by 12 minutes I reach my Vo2 Max, and we draw the test to a close. Once over Vo2 Max my ability to turn he pedals leaves me very quickly.

The outcome

p1050503I now spend five minutes spinning down until the heart recovers and the breathing becomes normal. This gives Patrick time to analyse the data and prepare the report.

The good news is that my heart appears the be performing as expected, controlled with no anomalies. The lungs are performing much higher than predicted for my age.

From this I now feel confident that the engine is strong and I am able to push it to get a bit more from it this year.

The bad news, if you can call it that, well, two things really.

My power was down on what I had expected, but having had a few muscle and joint issues from May 2018 onwards, the intensity of my training has been reduced. Most of my bigger power numbers were recorded before the end of April last year. Now that issue has been diagnosed and treatments started, I know I can now start and push harder for longer during training.


(The above shows the Glucides(%) and Lipides (%) usage up to the AT, where the fat burning stops. The upper red line is my heart rate and the ramp is the load being steadily increased)

Secondly, my Anaerobic Threshold (AT) kicked in at a lower heart rate/power than expected, but, its winter and the four hour Zone1/2 rides drop out of my schedule, usually replaced with two hour Z2/Z3 rides, trying to keep warm.


(The table above shows the breakdown of the four key zones, along with the energy source. The full table shows the power, heart rate and key measurments in these zones)

Whats next for me?

As I head in to February I hope to start doing some four hour plus rides, keeping the heart rate down, mixed in up with some two hour blasts. The heart rate will start to drop naturally as the loads related to riding in cold windy weather, heavy clothes, plus my heavy bike will be swapped out, which will be easier to haul up the hills.

I will also start to get some back to back days in the bag, as I start to take on some of my planned trips, bike packing in the UK.

I also need to book a second CPET test, between June and August, to see how effective the traing has been at increasing my AT capacity.

Would I recomend it?

Without dooubt. For anyone who pushes themselves, it is always useful to understand what your body is doing. For someone entering their second childhood, sorry retirement, it is reasuring to know that that body is still reponding positively to the stress you are putting it through.