What Is FTP and Why It Matters for Training

FTP (Functional Threshold Power) is the most useful number in cycling training because it anchors your zones. It tells you roughly how hard you can go for about an hour and helps you target the right intensity for every workout.

If you have ever wondered why one ride feels productive and another feels like random suffering, FTP is usually the missing piece.

Quick definition

FTP is the highest power you can sustain for about 40–60 minutes. It is a practical training benchmark, not a perfect physiological limit.

Why FTP matters

FTP gives you three things:

  • A way to set training zones that match your current fitness
  • A way to track progress over time
  • A way to pace long efforts without blowing up

When your FTP is accurate, workouts feel “hard but doable.” When it is off, everything feels wrong.

How FTP is tested

Most riders use one of these tests:

Test typeHow it worksProsCons
20-minute testAll-out 20 minutes × 0.95Accurate for steady ridersMentally hard, needs pacing
Ramp testShort ramp to failure × 0.75Easy to doCan overestimate for punchy riders
8-minute test2×8 minutes × 0.90Shorter & repeatableLess common, more variable

The best test is the one you will repeat consistently.

Simple rule

Re-test every 4–8 weeks, or after a training block, so your zones stay accurate.

How to use FTP in training

Once you have FTP, you can use zones with purpose:

  • Zone 2 builds aerobic base and endurance
  • Sweet Spot (just below FTP) builds fitness efficiently
  • Threshold intervals build sustained power
  • VO2max intervals raise your aerobic ceiling

If you are training 5–8 hours per week, sweet spot and threshold sessions are often the most effective use of time.

Common FTP mistakes

  • Testing on a bad day and then training off a low number
  • Using a ramp test that inflates FTP, making intervals too hard
  • Never updating FTP after gaining fitness

The bottom line

FTP is not perfect, but it is incredibly useful. It turns random riding into a plan and makes progress measurable.


References