Fractal scaling and complexity matching in ergometer rowing

Researchers increasingly acknowledge that athletes’ performance patterns emerge from multiple interacting components across different time scales. Recent research has shown “fractal scaling”, a hallmark of complex systems behavior, in the temporal structure of force-peak intervals of individual rowers’ strokes during an ergometer workout (Den Hartigh et al., 2015). In line with the notion of “complexity matching” in interpersonal interaction (Marmelat & Delignières, 2012), we examined whether the complexity indices of rowers would match when they do a workout together. Sixteen rowers of three rowing teams (two consisting of four members and one of eight members) did an individual workout and a workout with a team member, each consisting of 550 strokes. Results revealed 1) fractal scaling in each rower’s force-peak interval time series in the individual session, and 2) complexity matching between rowers in the dyadic session. Specifically, the correlation between the dyad members’ fractal dimensions was very strong when they rowed together (r = .90). This suggests that, during team rowing, interpersonal coordination takes place across multiple time scales.