FTP test

Definition

“FTP test” is a method of performance assessment in which the theoretical one-hour maximum, the functional threshold power, is estimated in the field. Since a full 60-minute maximal effort represents an enormous strain for most athletes and is hard to pace, a shorter protocol was developed. The standard is a 20-minute all-out test whose average power is corrected by 95 %.

FTP ≈ 0.95 × average power (20 min)

Why it matters

The background was to give athletes without access to a lab, for instance at a training camp, a way to keep their performance data current. The test needs nothing but a power meter and an hour of time.

The procedure has several problems, however. It is easily forgotten that functional power is not the anaerobic threshold but may merely be located near it. This misconception leads to training intensities far removed from reality that almost inevitably overload the athlete.

Another point: the method was developed on a very small reference group, exclusively male, in the elite segment and between 26 and 32 years old. For top athletes the test may be a valid method; for recreational sport it is anything but advisable.

The numbers speak for themselves: in over 1,000 lab measurements at most one athlete matched the metabolic functions and the definition of FTP as a power threshold in the region of the anaerobic threshold. Translated, the chance of accurate performance values from an FTP test is less than 1 in 1,000.

How obseed measures it

obseed runs no FTP test of its own and does not compute an FTP from your recordings. You can enter a value from a field test manually in the performance values; it is then used for TSS and load quantification, but not interpreted as a physiological threshold.

For deriving training zones obseed explicitly recommends metabolic diagnostics. Only there can you verify whether the intended stimuli are actually being triggered in the body. Anyone who uses the test regardless should repeat it under identical conditions and look at the trend, not the absolute value.

Example

An athlete rides a 20-minute test with an average power of 280 W.

FTP ≈ 0.95 × 280 W = 266 W

His training software sets zone 2 at 56–75 % of FTP, i.e. 149–200 W. In the diagnostic two weeks later his anaerobic threshold sits at 238 W and the FatMax range at 130–160 W. His “base sessions” by FTP zones therefore lie up to 40 W above the range in which his fat metabolism is actually being trained.