Interchangeability of the Polar Team Pro System in Determining Match Load and Intensities in Semi-Professional Rugby Union Players

This study assessed the interchangeability of the 10-Hz Polar and Catapult GPS during competitive matches. The agreement between data from both GPS units worn simultaneously and processed with the manufacturer's individual GPS-filtered software was also assessed. Thirty players competing in the Currie Cup first division competition were monitored using two different tracking systems across six matches. To determine the interchangeability between systems, player movement variables including total distance (TD), low-speed running (LSR, 0.0-14.4 km/h), high-speed running (HSR, 14.4-18.9 km/h), very high-speed running (VHSR, >18.9 km/h), acceleration efforts > 2.5 m/s(2) (ACC), deceleration efforts <-2.5 m/s(2) (DEC) and maximum velocity reached during each half were compared. The two systems showed good to excellent agreement (CCC = 0.83-0.98) during all selected variables. During the entire match, Polar had, on average, higher values than Catapult, except for LSR and HSR. The percentage differences between systems were 3.6% TD, 1.9% maximum velocity, -4.7% LSR, -4.6% HSR, 16.5% VHSR, 13.7% ACC and 11.9% DEC. In addition, Bland-Altman plots showed a low average difference for TD (129.1; 90.1 m), maximum velocity (0.5; 0.5 km/h), LSR (138.2; 80.9 m), HSR (21.3; 5.4 m), VHSR (35.7; 22.3 m), ACC (1.6; 1.8 efforts) and DEC (2.0; 1.2 efforts).