Testing-why do we do it?

Bike tests, 5km run tests, CSS swim tests….why do we do it? What is it for? Is it important for our success as an athlete?


For the majority, next week will see TTT entering a baseline measurement (test) week. Critical Power testing on the bike is the main group focus and we will be providing 4 opportunities to join group sessions on Zwift and Discord to allow you to get the most from your tests. This is a huge strength for us at TTT as we can utilise our extensive community of coaches and athletes to help educate and motivate you at this time. Recognising that some amongst you may not be able to test next week due to illness, injury, work or family commitments we can of course move your sessions back a week or two so don’t panic.

Why do we need to test and why right now?

• To understand each individual’s unique ability.

• To set realistic targets, allowing growth and preventing over-training or disappointment.

• To measure both changes over time and with certain training methods.

“We need to train the person you are now, not the one you were last season or the one you want to be next season” Ellison, 2021.

I want to emphasise that these tests are purely benchmarks to start your preparation for the 2022 triathlon season. We will not expect to see many personal best performances at this time of year and in fact this is not particularly advantageous right now as we look to have you all in peak condition many months from now.

So be prepared, that from next week, we may actually look to reduce your threshold power on Training Peaks and Zwift. This is NOT FAILURE – but setting yourself up for success!

Why Critical Power and what is it?

Let’s start by looking at FTP, which is probably more familiar to you… I’m sure most of you reading this know your FTP and possibly, dare I say it, even like to tell others about it! Your Functional Threshold Power, as the name implies, is the highest amount of power (watts) that you can produce over a sustained period of time (a.k.a 1 hour power), therefore making it functional or useful. FTP is a valid and reliable measure of your cycling ability and changes in your fitness over time. For instance, if your FTP is 220w and after 8 weeks of training it has risen to 240w then we can be sure you have improved as a cyclist. All things considered your sustainable power is the biggest single determinant of your cycling ability.

The most common way of measuring FTP (in recent times) has been to shorten a one hour time trial effort (after all who wants to do that on a regular basis) to one of 20 minutes. A shorter test can be more easily scheduled into a training program and can be repeated more regularly to track changes in fitness, as it doesn’t require quite the same motivation or time allowance as a longer test. We can then predict a more sustainable power from the shorter test (95% of 20min power). However, for many athletes this calculation may not provide an accurate number. Also, the length of time that you are actually able to pedal at your FTP (known as TTE – time to exhaustion) is highly variable. Consider your FTP number from your last or best 20min test – how confident are you that you could cycle at that wattage for say 45 minutes let alone a full hour? The major problem with this method of testing is that it is not individualised and relies on one single point of measurement (power at 20mins) to make sweeping assumptions about an athlete’s physiology.

For example, two athletes with an FTP of 300w would be viewed as the same, when we now know that they could in fact be very different. The relative contributions of their aerobic and anaerobic energy systems could differ considerably. A second issue with the 20 minute FTP test is that calculated values are often too high which, whilst good for our egos, is not ideal for subsequent training and can often leave us over-reaching and struggling to meet our targets.

Enter Critical Power (CP); the method currently preferred at Total Tri Training

The way we use this model, with 2 test procedures, allows more accurate understanding of each athlete and the way in which they produce energy/power. A shorter test (typically 3-5 mins) provides a very good measure of anaerobic power (from energy made without oxygen) and a medium test (12-20 mins) provides a measure of both anaerobic and aerobic (with oxygen) power production. We then have 2 data points (power at 3 and 20mins say) along an individuals power curve.

Comparison of the short and medium length tests allows us to more accurately assess your sustainable power (CP) and to tailor your training prescription based on the relative contributions of the aerobic and anaerobic systems. Further detail is beyond the scope of this little blog but rest assured that next weeks tests will prove extremely useful and will set you up for a fantastic winter of training with TTT. Your coaches will be happy to provide further explanation of critical power for those who want it and for those who don’t… just “pedal dead hard” and trust in the results. Thanks for reading

Go well !

Thank you Phil Ellison