4DP Test / Profile
The 4DP test is a cycling field test of four intervals (5 s, 1 min, 5 min, 20 min) that captures sprint, anaerobic and VO2max power alongside FTP.
Definition
“4DP Test / Profile” refers to a single continuous cycling field-test protocol that measures power over four intervals of different length and derives a four-dimensional power profile from them. “4DP” stands for “Four Dimensional Power”. Alongside FTP it captures neuromuscular power (5 seconds), anaerobic capacity (1 minute) and VO2max potential (5 minutes).
| Dimension | Duration | Abbreviation | What it represents |
|---|---|---|---|
| Neuromuscular power | 5 s | NM | Sprinting, maximal force production |
| Anaerobic capacity | 1 min | AC | Short, hard surges and attacks |
| Maximal aerobic power | 5 min | MAP | VO2max potential, climbs |
| Functional threshold power | 20 min | FTP | Endurance at threshold |
Why it matters
A plain FTP test describes an athlete with a single number. Two riders with identical FTP can differ enormously in sprint and five-minute power. The 4DP profile exposes those differences and allows a first typing: sprinter, anaerobic, aerobic or all-rounder.
Without access to metabolic testing, the 4DP test therefore paints a somewhat more informative picture of the status quo than a 20-minute test alone. It remains a field test, though: it measures power, not metabolism. Where the aerobic or anaerobic threshold actually sits cannot be determined objectively this way, only estimated.
How obseed measures it
obseed does not run the test itself. The protocol is ridden with a power meter on the road or a smart trainer and recorded as a normal session, ideally with one lap per interval (see Recording sessions: Cycling). Once the recording is imported, the four interval values are visible as the average power of each lap.
The FTP derived from it is stored in obseed as a performance metric and used for zones and load metrics. obseed consistently treats all four values as field-test estimates. If data from a metabolic assessment exists, it takes precedence, because it delivers real physiological thresholds instead of arithmetic approximations.
Example
A 72 kg rider completes the protocol with the following average powers:
| Interval | Power | Relative |
|---|---|---|
| 5 s | 1,080 W | 15.0 W/kg |
| 1 min | 470 W | 6.5 W/kg |
| 5 min | 335 W | 4.7 W/kg |
| 20 min | 280 W | 3.9 W/kg |
FTP is estimated using the usual field-test convention of 95% of 20-minute power:
FTP ≈ 280 W × 0.95 = 266 WThe MAP-to-FTP ratio is 335 / 266 = 1.26. Values around 1.2 to 1.3 are considered balanced. If five-minute power were 300 W (ratio 1.13), aerobic capacity would be nearly exhausted at threshold, and the training focus would shift towards VO2max work rather than more threshold work.
Whether that interpretation holds is only revealed by spiroergometry: it measures where the ventilatory thresholds actually lie instead of estimating them from watts.
Categories
- Datenanalyse
- Diagnostik