This week we’re talking about pace (aka split). That’s the number that looks like this → x:xx/500m, on your screen.
Limiting our discussion to just the rowing machine for the moment, this number tells you the amount of time (minutes:seconds) you would take to row 500 meters. The lower the number, the less time you take to row 500m, which means that your imaginary “boat” is moving faster.
Like power, this number is updated every stroke and is a (moving) average of your last two strokes. In fact, pace is calculated from power using the formula: pace = ³√(2.80/watts).
Unlike power, pace does not change proportionately with the effort put into the machine. In fact, pace varies with the cube-root of power. So, for example, to double your pace, you would need to produce not just twice, but eight times as much power! Consequently, when using pace to track your improvement, you’ll notice that the faster you get the harder it is to bring your split down further. This is again the reason why we encourage beginners to pay more attention to watts rather than split for tracking their progress. That being said, pace does have its place even for beginners – it’s much more practical to plan a workout based on distance and time, rather than by power!
The reason why pace varies with cube-root of power is to mimic the effect of water resistance on our imaginary “boat”, where resistance increases significantly was we try to move faster through the water.
If you are observant and mathematically inclined, you might be asking where the factor 2.80 in the above formula comes from. This is a number empirically chosen by the manufacturer such that the pace shown on the screen approximately equals the speed of a “real” 4- boat (i.e. a boat with 4 people rowing) for that amount of power generated by each of the 4 athletes. While a discussion of boat types is beyond the scope of this series, suffice to say that this choice by the manufacturer was probably made so that the pace shown is somewhere between the slowest boat (1X) and the fastest (8+) one.
Next week, we’ll continue our discussion of power and pace and explore some interesting implications of the cube-root relationship! As usual, questions are more than welcome!