This chart relates average pace (time/500m) to average power on a Concept 2 ergo. The equation used has been inferred from the figures contained in "Elite Ergometer Performance Analysis", a very interesting article by Stephen Seiler.
The chart captures the cubic relationship between velocity and the power required to produce it. The fastest pace here (1:26) is representative of the world record standard for indoor rowing over 2000m, as set by Greg Searle (5:44.1) in the 19-29 age group, and Steven Redgrave (5:46.8) in the 30-39 age group.
The derived equation used to produce the chart is as follows:
where
v is 'velocity', i.e. ergo distance over ergo time.
Scaling the above power figures according to weight, gives a reasonable indication of on-water performance, assuming good technique. The scaled power figures may then be converted back to 'weight-adjusted distances' using an approximation to the inverse cubic relationship above.
Here the performance during the first 45 seconds of a 5 minute ergo piece is assumed to be dependant upon anaerobic respiration, with the remainder dependant upon aerobic respiration. The scaling technique suggested by Stephen Seiler has been employed.
The chart allows a ready comparison of the on-water performance of different rowers, predicted according to a raw 5 minute ergo score and body weight. To use the chart, draw a line vertically upwards from the ergometer distance reading on the horizontal axis until it meets the body mass of the rower, then across horizontally to give the weight-adjusted distance. The adjusted distances are relative to each other, and would require a linear scaling factor to make them absolute to any particular boat. An A4 sized version of the chart is available as a PostScript document. The data used to produce the chart is available as an Excel-compatible spreadsheet (exported from ClarisWorks).
The equation this time is a little more involved:
where
x' is the weight-adjusted distance
k is the linear-scaling factor appropriate to a particular boat and set of conditions
x is ergo distance
m is body mass
t is ergo time = 300
a = 45.769, b = 242.45, c = 421.93, d = 0.215
e = 42.64, f = 227.4, g = 398.0
