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01Chapter 1 · The engine and the erg

Double the watts. The split drops 21%.

  1. Slide 1: Double the watts. The split drops 21%.. RowErg or SkiErg · per 500 m. Example

    Slide 1 of 6

    • Double the watts. The split drops 21%.
    • RowErg or SkiErg · per 500 m
    • Example
    • 200 W: 2:00.5
    • 400 W: 1:35.6
  2. Slide 2: 01 · The formula. Watts grow with speed cubed. Concept2 · watts = 2.80 ÷ pace³

    Slide 2 of 6

    • 01 · The formula
    • Watts grow with speed cubed
    • Concept2 · watts = 2.80 ÷ pace³
    • Concept2
    • Split: 2:05.0
    • Power: 179.2

    SourceConcept2 Watts Calculator

  3. Slide 3: 02 · 10% faster. 10% faster costs 33% more. Per 500 m

    Slide 3 of 6

    • 02 · 10% faster
    • 10% faster costs 33% more
    • Per 500 m
    • Example
    • 2:00.0: 202.5
    • 1:49.1: 269.6

    SourceComputed from the Concept2 formula · EXAMPLE

  4. Slide 4: 03 · One second. One second costs more as you get quicker. One second off the split

    Slide 4 of 6

    • 03 · One second
    • One second costs more as you get quicker
    • One second off the split
    • Example

    SourceComputed from the Concept2 formula · EXAMPLE

  5. Slide 5: 04 · Concept2's example. 30 seconds, then 15, same 100 W. About 100 W each

    Slide 5 of 6

    • 04 · Concept2's example
    • 30 seconds, then 15, same 100 W
    • About 100 W each
    • Concept2
    • 2:30 to 2:00: +100
    • 2:00 to 1:45: +100

    SourceConcept2, Training with Watts on Your Concept2 Erg

  6. Slide 6: 05 · The other way round. Time moves a third as much. On a rowing erg

    Slide 6 of 6

    • 05 · The other way round
    • Time moves a third as much
    • On a rowing erg
    • Example
    • Power: +3%
    • Speed: +1%

    SourceSchabort et al. 1999, J Sports Sci 17:627 · EXAMPLE

In short

Double your watts and your split drops about 21%. It doesn't halve. 200 watts is a 2:00.5 split. 400 watts is 1:35.6.

On the rower and SkiErg, power grows with the cube of speed. 10% faster takes about 33% more power.

The same one second costs more as you get quicker: 2:30 to 2:29 is 2.1 W, 2:00 to 1:59 is 5.1 W, 1:45 to 1:44 is 8.8 W.

A rowing study put it the other way round: changes in time are about a third of the changes in power.

Every number comes from Concept2's formula. The splits are examples.

Turn pace into watts, and watts into pace, on any Concept2 erg.

Open the machine converter

Or start in Telegram.

Sources

  • Concept2 / web

    Concept2 Watts Calculator (concept2.com/training/watts-calculator, fetched 31 Oct 2026): 'watts = 2.80/pace³ ... where pace is time in seconds over distance in meters'; worked example 'a 2:05/500m split ... equals 179.2'

    concept2.com/training/watts-calculator

  • Concept2 / web

    Concept2, Training with Watts on Your Concept2 Erg (blog, 20 Aug 2025): 'improving your pace from a 2:30 split to a 2:00 split requires an increase of approximately 100 watts (from 104W to 203W). However, to improve your pace by only half that time, from a 2:00 split to a 1:45 split, requires a nearly identical 100-watt increase (from 203W to 302W).'

  • Paper

    Schabort EJ, Hawley JA, Hopkins WG, Blum H (1999) High reliability of performance of well-trained rowers on a rowing ergometer. J Sports Sci 17(8):627-632. doi 10.1080/026404199365650, PMID 10487463 ('Variability and changes in performance expressed as time to complete the test were approximately one-third those of mean power, apparently because simulated velocity is proportional to the cube root of power on this ergometer'; slide 6)

    doi.org/10.1080/026404199365650

  • Worked out

    Computed: 200 W = 120.51 s = 2:00.5; 400 W = 95.65 s = 1:35.6; split ratio 2^(-1/3) = 0.7937 (20.6% shorter)

  • Worked out

    Computed: 2:00.0 = 202.5 W; 120/1.1 = 109.09 s = 1:49.1 = 269.6 W; 1.1^3 = 1.331 (+33.1%)

  • Worked out

    Computed one second: 2:30.0 103.7 W, 2:29.0 105.8 W (+2.0%); 2:00.0 202.5 W, 1:59.0 207.7 W (+2.5%); 1:45.0 302.3 W, 1:44.0 311.1 W (+2.9%)

  • Worked out

    Computed: +3% power is +0.99% speed (cube root), about 1%

Nothing here is medical advice. The tests are maximal efforts: if you have a health condition or any doubt about training this hard, check with a doctor first, and stop if you feel unwell.