You might ask why it is necessary to row at r20. After all, you could pull just as hard per stroke at 24 or 28. The answer to this might as well have been devised by a medieval inquisitor. If you row at 28, the acid will accumulate in the muscles (and in the body generally) too quickly so that you will be “released” from the lactic acid bath after just a few minutes. By dropping the rate down, you give your body time to move the acid away from the working muscles and to have at least some of it broken down by those muscles which are not working hard. Since 85% of the energy in glucose remains unreleased in lactic acid, the acid is actually a rich source of fuel, particularly for those muscle cells with very high aerobic capability (for heart muscle cells it is the fuel of choice). By allowing 3 seconds per stroke, you can get enough oxygen in to maintain an uneasy equilibrium for much longer. In fact at Q-Power we regularly do a variation on this theme, for example 30x1:00[1:00] r20 where even larger amounts of power can be produced, but with enough rest time to allow the hapless victim to survive for the whole session... well, just about.

Does a relatively good 30r20 score mean a relatively good 2k. Not necessarily. The correlation between 30r20 performance and other sessions is not great (although there is some broad relationship of course). The reason for this is that the session is hugely advantageous to those who are very tall and can row very long strokes. To compare a 30r20 with an unrestricted rate piece, if you are 6’6” the rate difference between the two may not be all that great. However if you are 5’10” then the gap will be significantly bigger. Even just a few strokes per minute makes a big difference (as anyone who has resigned to the solace found in rowing the last 10 minutes of a 30r20 at r21 knows; you know who you are, and most people reading this will know the dissatisfied feeling you had to endure long after the row ended).

What one can say, however, is that if your 30r20 is improving, then your 2k time come the next racing season will as well. 30r20s put a huge strain on the body, and once per week is enough, but they are worth doing, and worth doing well.