Antiphase crew rowing on water: a first case study.

In crew rowing, agents need to mutually coordinate their movements to achieve optimal performance (De Poel, De Brouwer, & Cuijpers, 2016). Traditionally, rowers aim to achieve perfect synchronous (in-phase) coordination. Somewhat counterintuitively, however, crew rowing in an antiphase pattern (i.e., alternating strokes) would actually be mechanically more efficient: it diminishes the within-cycle surge velocity fluctuations of the boat, thereby reducing hydrodynamic drag and hence power losses with 5-6% (Brearly & DeMestre, 1998; De Poel et al., 2016; De Brouwer, De Poel, & Hofmijster, 2013; Cuijpers, Zaal, & De Poel, 2015, Greidanus, Delfos, & Westerweel, 2016). However, from coordination dynamics an antiphase pattern is expected to be less stable, especially at high stroke rates such as in racing, which may even lead to transitions to the more stable in-phase pattern (Haken, Kelso, & Bunz, 1985). Recent laboratory studies in which rower dyads performed antiphase crew coordination on two mechanically coupled ergometers have provided promising results (De Brouwer et al., 2013; De Poel et al., 2016; Cuijpers et al., 2015;). However, counter to ergometer rowing, rowing on-water also requires handling of the oars and boat movements in three dimensions, such as lateral balance and forward speed. Furthermore, the boat has actual forward speed. Therefore, the next step in this endeavour is to examine antiphase crew rowing and associated boat movements on water. Here we report results of the first test case.