This short how-to explainer is an accompaniment to the recent article on Internal Load Monitoring for Cyclists by Associate Professor Mike Posthumus. The Submaximal Fatigue Test (SFT) is a key component of how Science to Sport coaches monitor athlete training load, freshness and fatigue, usually on a fortnightly (every 2 weeks) schedule.

Submaximal Fatigue Test

A simple S2S protocol for monitoring training fatigue

3min

Duration

110%

of FTP

Fortnightly

Frequency

Simple

Execution

The Protocol

CALC

Get Your Test Power

Select the target power for your SFT with your coach if you have one. This number is set for the entire season. Usually 110% of your FTP.

Calculation

FTP × 1.10

Example: 250W FTP = Hold between 250W & 275W for 3 mins.

WARM

Warm Up

10-15 minutes of non-specific riding. No need for any sprints or activation.

HR

Record Heart Rate

Make sure your HR strap is linked to your bike computer so that your session has HR data. Analysis depends on the average HR for the last minute of your SFT.

TEST

Perform the 3-Minute Test

Hold your target power as steadily as possible for exactly 3 minutes. This should feel hard but controlled - like a 20-30 minute time trial pace.

Power meter essential - coaches need power data to interpret test data effectively.

RPE

Record RPE Immediately

Within 10-15 seconds of finishing, rate how hard the effort felt using the Borg scale (6-20). Expected range is 14-16 for this test.

TTE

Estimate Time to Exhaustion

Answer: "How many more minutes could I have held that power?" We have found that this estimation is often more sensitive in cyclists compared to only reporting RPE.

WELL

Complete Wellness Questions

Answer five S2S subjective wellness questions about your fatigue, sleep, stress, mood and overall feeling.

Key Points to Remember

Consistency is Everything

Same time of day, same day of week, same warm-up routine

Indoor or Outdoor

Pick one testing method and stick with it - consistency matters more than location

Part of Your Warm-Up

Many athletes do an SFT before scheduled workouts - very little extra training load

Track Trends

Work with a Science to Sport coach, qualified physiologist or coach in detecting and interpreting trends in your test data.

Your Feelings Matter

Subjective data (RPE, wellness) is just as important as power and HR

Don't Change Target Power

Keep your initial target power the same all season, regardless of FTP fluctuation.

Related Content & Articles

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