A Submaximal Fatigue Test Protocol to Monitor Cyclist Training Load
This short how-to explainer is an accompaniment to the recent article on Monitoring Cyclist Training Load Part 2: The Submaximal Fatigue Test & Internal Load Metrics 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.
The Protocol
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.
Warm Up
10–15 minutes of non-specific riding. No need for any sprints or activation.
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.
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.
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.
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.
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.
Work With an S2S Coach
Whether you're optimising performance for a specific race or building long-term aerobic capacity, our coaches design individualised programmes around your physiology, goals, and schedule.
