How To Test Your Triathlon Fitness

Fitness tests are a great way to track your triathlon training progress.

We recommend that our athletes measure their fitness every eight to twelve weeks, with three simple tests. We show you how…

There are three individual tests, one each for swim, bike and run. Ideally, you should do them during a recovery week, so that you’re not tired. And it’s a good idea not to train hard for 48 hours between the bike and run tests, so that you are fresh for them both.

We’ll start by explaining how to do the tests. And then at the end of the article, we’ll reveal some important things to consider when you analyse the results of your fitness tests.


1. The Swim Fitness Test

We use a Critical Swim Speed (CSS) test.

This simple test gives you a good idea of your current fitness and can also be used to set your pace-based training zones for swimming. The aim of a CSS test is to predict your current race pace for 1500 metres or yards. The beauty of the test is that you don’t actually have to swim that far.

Swim Test Protocol:

To test your current CSS pace you need to swim a 400 and 200 Time Trial within the same session. Swim as hard as you can for both time trials, with around 5-10 minutes of active recovery in between. Ideally, get a friend or coach to time you and record your 100 splits and strokes per minute. Failing that, simply record the 400 and 200 times yourself.

CSS tests are included in our training plans every 8 weeks (during a recovery week). This will give you an idea of your current fitness and also allows you to update your training zones

After you’ve done a CSS swim test, use our online swim calculator to work out your current CSS swim pace (per 100). You can also create five training zones, to use with our training plans.

2. The Bike Fitness Test

We use a Critical Power 20-minute test (CP20). This simple test gives you a good idea of your current fitness and can also be used to set your power-based training zones for cycling.

The aim of a CP20 test is to predict your best average power output for a one-hour steady state time trial, without actually having to ride hard for an hour.

Bike Test Protocol:

  • Warm Up: 15 minutes easy/steady, with at least 5 x 10 seconds at your approximate test pace.
  • Test: Ride for 20 minutes, at the hardest effort that you can sustain throughout. Making sure you’re measuring your average (mean) power and heart rate during the 20 minutes.
  • Warm Down: 5-10 minutes easy spin.

What was your average power for the 20-minute test? For example 200 watts. This is known as your CP20 (the CP stands for Critical Power). Once you know your CP20 you can also estimate your CP60 (known as Functional Threshold Power or FTP). Simply multiply your CP20 test result in Watts by 0.95. For example, if your CP20 is 200w, your FTP would be 190w. If you use Training Peaks you should enter your threshold into your Settings. You can also create your five training zones using our online bike calculator.

3. The Run Fitness Test

We use a Threshold Run Pace test to measure your fitness. Threshold running pace is a measure of your current best pace for a 60-minute race. It is a useful benchmark of your running fitness and is often used to create pace-based training zones.

You can get a good idea of your threshold run pace without having to do a 1-hour race. You simply need to do a 30-minute solo time trial with no training partners. You’ll just need some way of measuring your average pace, such as a GPS watch or smartphone.

Once you know your threshold run pace, you can create training zones using our online run calculator. If you use Training Peaks, you should also enter your threshold into your settings.

Run Test Protocol:

Start with a warm up of 15 minutes, mainly easy jogging with three or four  15-second accelerations up to approximate 5km race pace.

Then begin the 30-minute time trial. Press start on your phone or watch and run at your fastest sustainable pace for 30 minutes. After you’ve completed the 30-minute test, stop your watch/phone.

What was your average run pace throughout the test? This is your new Threshold Running Pace. What was your average heart rate throughout the test? This is your new Running Threshold Heart Rate.

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Summary Tips

The three tests described above will measure your ability to perform for one hour in cycling and running. And for around 20-30 minutes for swimming. These are excellent measures for Sprint and Olympic distance triathlons. And they are still useful fitness measures for longer triathlons like Ironman 70.3 and Ironman 140.6.

It’s important to understand that these tests are not direct measures of your stamina (your ability to keep going for hours and hours).

That said, improved test scores will also signal small improvements in your stamina. Because the higher your FTP, CSS and Run Threshold Pace, the easier it will feel to maintain a given pace.

Another thing to consider is that you can’t expect big improvements every single time you do triathlon fitness tests. The path of improvement is not always linear.

Over time your test results might look something like a chart of a stock market, for example, the S&P 500. The overall trend is upwards, but there are ups and downs along the way.

You don’t necessarily need to change your training if you don’t set a new best score in a test. It’s hard to continually improve at all three disciplines and life also gets in the way sometimes. There are so many variables to consider, it’s usually better to step back and look at the long term trends before you make sweeping changes.

Phil Mosley (Coach & Founder)
Phil Mosley (Coach & Founder)

Phil is a recognised endurance expert who founded MyProCoach in 2010 to offer smart training plans that still leave quality time for your family, friends & career - complete with highly-rated coach support (he has sold over 40,000 so far). Learn more here!

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