Threshold Tests for Swim, Bike and Run

The phrase “FTP test” most likely strikes fear into your heart when they appear on your weekly training plan. Fortunately, there are lots of new threshold tests which can help approximate your results without the time or mental stress of a traditional FTP test.

The phrase “FTP test” most likely strikes fear into your heart when it appears on your weekly training plan. While FTP testing can be extremely difficult and even disruptive to your training, it is necessary to set effective training intensities and measure your progress. Fortunately, there are lots of new threshold tests that can help approximate your results without the time or mental stress of a traditional FTP test.

Functional Threshold Power, or FTP, is a term coined by Dr. Andrew Coggan as a proxy for lactate threshold. Essentially, this is the intensity of exercise at which an athlete begins producing lactate faster than their body can process it, resulting in a performance plateau and eventual decline. This turning point represents a useful physiological marker that is highly correlated with an athlete’s endurance performance. Basically, the higher your FTP, the harder you can go for longer.

Lactate threshold can be applied to other markers such as pace or heart rate. But to get the best, most accurate results, you would want to perform a solo time trial in your preferred sport for around an hour. Unfortunately, this method of determining your threshold is extremely difficult and mentally taxing — so taxing that (unless you have a 40k time trial on your race calendar) it is not recommended.

Hunter Allen and Andy Coggan, authors of Training and Racing with a Power Meter, recognized this and came up with an alternative test. Rather than an hour, they found that athletes could perform a twenty-minute time trial and subtract 5% from the final result to provide a reasonably accurate estimate of what their result would have been for a full hour. Over the last 18 years, this has become widely accepted as the best way to test your Functional Threshold Power.

But that hasn’t stopped smart coaches from devising even more ways to test your FTP. Most of them are shorter—though not necessarily easier—and just as effective for most goals. If you are new to structured training (or can’t bear the thought of a 20-minute time trial), then one of the threshold tests listed below might be just what you are looking for!

Swim Threshold Tests

1,000 yard/meter time trial

In this test, you swim 1,000 meters as fast as you can without a break. Then take your average 100-meter time for the test and apply that as your Threshold Swim Pace. In TrainingPeaks, you can either enter your average 100-meter time in seconds under Threshold Pace, or you can select “Distance/Duration,” select the distance of your test and enter your result; the app will then calculate your threshold for you.

Alternative Test

Critical Swim Speed

This test uses two much shorter efforts, such as 400 and 200 yards or meters, and then you plug your results into the following equation and are given a CSS (Critical Swim Speed) which can then be entered into TrainingPeaks as your threshold swim pace.

The simple way of doing it is the difference in time between the 400m and 200m divided by 2.

CSS/100m = (T(400)-T(200))/2

For example, if you swam the 400 in 6 minutes and the 200 in 3 minutes, it would look like this. CSS/100m = (T(360)-T(180))/2=180/2=90 seconds per 100

400-yard/meter time trial

Simon Ward of The Triathlon Coach recommends a 400 m time trial for determining Lactic Threshold.

“We have started using a 400m TT in the pool,” Ward says. “This approximates to a Vo2 max effort (5-8 minutes generally for our swimmers) If you take the pace per 100 meters and add 4-5 seconds, this gives a good estimate of CSS time. If you add 8-10 seconds/100 meters, this would provide a reasonable estimate of Endurance pace. We have compared to CSS pace/100 meters, and also to a straight 1500 meters, and the paces are within 1-2s/100 meters. I find this to be fine for most AG athletes, although elite age groupers and pro swimmers may require more accuracy.”

Cycling Threshold Tests

20 minute Time Trial

Find a quiet section of uninterrupted road or a trainer, and (after a thorough warm-up) ride as hard as you can for 20 minutes. Take your average power for the 20 minutes and subtract 5% to get your Threshold Power.

30 minute Time Trial

Popularized by Joe Friel, this field test is identical to the previous one, except you ride for 30 minutes. This time, however, you will use the average power for the entire 30 minutes as your Threshold Power. Joe figures that when you do this test alone, you feel about 5% sorry for yourself, so there is no need to subtract any watts from the result to estimate your hour power.

Critical Power

Introduced by Monod and Scherrer in the 1960s, this version takes your best power from a short test (around 3-5 minutes) and a longer test (20-30 minutes) and models it out over longer durations to estimate the theoretical power you could produce aerobically for a long time—also known as Critical Power (CP). CP tends to overestimate one-hour power by a little bit, but it is close enough that it can be used interchangeably with FTP. A quick internet search will reveal some CP calculators available on the web, or you can calculate yourself with the following formula:

CP = (AP1(T1)-AP2(T2)/T2-T1

Multiply the average power of the short interval by the number of seconds in the short interval to get joules. Then multiply the average power for the long interval by the number of seconds in the long interval, again to get the number of joules. Next, divide the difference in joules for each interval by the difference in seconds, and you get your Critical Power. For example, if you did a 5-minute test where you averaged 300 watts and a 20-minute test where you averaged 285 watts, it would look something like this:

CP= 300w*300s-285w*1200s/1200s-300s

CP=90,000j-342,000j/900s

CP=252,000jj/900s

CP=280

Or better yet, just use an online Critical Power Calculator!

Alternative Tests

8-minute Time Trial

This test uses two 8-minute time trials to estimate your FTP. It was created by Chris Carmichael and his coaches at Carmichael Training Systems (CTS). To perform this test, you warm up well and then ride at the highest effort you can for eight minutes. Recover by riding easily for 10 minutes, and then repeat the eight-minute test. When you are done, look at your highest average power for the two tests and subtract 10%. This number can then be entered into TrainingPeaks as your Threshold Power.

1-Minute Ramp Test

While ramp tests have been around for a while, TrainerRoad has devised a new version in which you start at a fairly easy effort and then increase your wattage a little bit every minute until you can no longer continue. Then, take 75% of your highest 1-minute power from the test to estimate your FTP.

3-minute Critical Power Test

While this test may sound easy, it is actually quite difficult. Simply ride three minutes all out. That means no pacing at all; just give everything you’ve got for the full 3 minutes. Whatever your average power is for the last 30 seconds of the test is your Critical Power/FTP.

Running Threshold Tests

30 minute Time Trial

This is another test popularized by Joe Friel. In it, you run as fast as you can for 30 minutes. Once you complete the test, you can look at your file in TrainingPeaks and use the average pace and/or heart rate for the last 20 minutes.

5k/10k race

If you have recently run a 5k or 10k race, you can enter the results in TrainingPeaks to calculate your threshold. Calculators for other distances are available online. The “Peak Performances” feature in TrainingPeaks comes in handy here; you can be notified when you’ve set a new peak, which means it might be time to update your threshold.

Alternative Tests

Critical Velocity

Like critical power for cycling, this time, we will use two shorter durations, three minutes and nine minutes, to calculate your CV or Functional Threshold Pace.

3-minute Critical Velocity

Just like the three-minute CP test for the bike above, this one is performed ALL OUT with no pacing. Take the last 30-45 seconds of the effort and you have your threshold pace.

Modeled Functional Threshold Power (mFTP)

Introduced in our desktop software WKO5, this function looks at all of the data uploaded in the last 90 days and then models your FTP through regression mathematics to come up with the best fit.

Estimating Based on Perceived Exertion (PE)

7 out of 10 is highly correlated with MLSS.

If you have been postponing your next field test because you can’t bear the thought of another 20-minute or 1,000-yard time trial, consider using one of the other methods above. While most sane people don’t enjoy testing, the results you get will make the fun parts of training more effective!