Power profile and eFTP

The power profile is your best average watts across durations, from a 30-second sprint to a marathon. Set beside an expected shape, it shows where you are strong for your 2K and where you trail it.

The curveCopy Anchor Link

The curve has 11 anchors: 30 s, 1:00, 500m, 1,000m, 2,000m, 5,000m, 6,000m, 30:00, 10,000m, the half marathon and the marathon. The chart runs from 30 seconds to one hour on a log scale. The half marathon and marathon sit past the hour, so they appear in the table only.

A best counts for an anchor when its duration is within 15% of that anchor's typical duration. An anchor with no such best is not rowed. Ergon never draws a guess in its place.

The chart draws three lines:

• You: your bests from the last 90 days.
• All-time: your bests from your whole history.
• Expected: the shape a balanced rower with your 2K would draw.

Where expected sits above you, the gap between the lines is shaded.

The expected shapeCopy Anchor Link

Expected watts at each anchor are your 2K watts times a fixed ratio.

The 1:00, 6,000m and one-hour points come from Kurt Jensen's profile of elite rowers. The rest are filled by Paul's Law: about 5 seconds slower per 500m each time the distance doubles. It is a shape scaled to you, not a target in watts.

The 2K is your best genuine 2,000m on this machine in the last 365 days. With no 2K, the shape is scaled from your power anchor: the threshold watts you entered, or eFTP. The table's vs expected column is each anchor's watts against the shape, as a percent. The 2K that sets the shape reads ref.

Your typeCopy Anchor Link

Ergon names a type once three anchors are measured: a 1:00 (or 30 s), a 2K, and one long piece of 30:00 or more. Each group is compared against the expected shape. A difference counts when it is larger than 6%.

• Foundry: your 5K and 6K are more than 6% below expected, and below both other groups.
• Piston: your short end beats your long end by more than 6 points.
• Turbine: your long end beats your short end by more than 6 points.
• Dynamo: none of the above. The curve is close to balanced.

The long end is your longest measured piece of 30:00 or more.

eFTPCopy Anchor Link

eFTP is an estimate of the watts you could hold for an hour. It is also the anchor for your power zones when you have not entered threshold watts.

Ergon fits a critical-power curve to your bests between 2 and 20 minutes: watts = W′ ÷ duration + CP. CP is the power you can sustain. W′ is the work you can do above it. eFTP = W′ ÷ 3,600 + CP, the curve's value at one hour. The fit needs at least two durations, the longest at least twice the shortest.

With no fit anywhere, eFTP is 83% of your best 2K from the last year. With no 2K either, Ergon infers a 2K from your best piece between 2 and 20 minutes, then takes 83% of that. Both are low confidence.

Guards on eFTPCopy Anchor Link

• The 2K cross-check. A fitted eFTP must sit between 78% and 88% of your best 2K. Outside that band it is pulled to the edge and marked low confidence.
• No cliff. A new estimate can raise eFTP at once. It can lower it by at most 5% every 30 days.
• No hard reset. With no new efforts, eFTP holds, decays at the same 5% per 30 days, and reads stale.

The readingsCopy Anchor Link

• W/kg: eFTP ÷ your body weight, when Ergon has a weight for you.
• Anchors: how many of the 11 you have measured.
• Last test: how long ago your newest measured anchor was rowed.

The rows beneath the table name the pieces that complete the profile. Once every anchor is measured, the row offers a re-test of the oldest.

Honest limitsCopy Anchor Link

• The shape is elite. Most club and masters rowers read a little weak on the long end against it. That is the reference, not a verdict.
• Each machine is its own profile. A RowErg 2K never scales the SkiErg's shape. The BikeErg has no 2K event, so its shape is scaled from its own power anchor.
• Only real efforts count. A steady 10K is not a maximal 10K. The profile reads the best you have rowed, not the best you could row.