Table 1. Test-retest reliability of the Polar V800 sports watch, force platform and high-speed camera

	Systematic Bias (cm)	Random Error (cm)	Proportional Bias	ICC (95% CI)	CV (%)
Polar V800, SJ	-0.37	3.14	No	0.90 (0.80-0.93)	4.83
Force Plate, SJ	0.44	3.59	No	0.83 (0.71-0.90)	6.20
Kinovea, SJ	-0.18	2.81	No	0.89 (0.81-0.94)	4.11
Polar V800, CMJ	-0.77	3.29	No	0.90 (0.81-0.94)	4.66
Force Plate, CMJ	-0.09	3.82	No	0.84 (0.73-0.91)	5.90
Kinovea, CMJ	-0.31	3.44	No	0.86 (0.77-0.92)	5.24

CI: confidence interval; CMJ: countermovement jump; CV: coefficient of variation; ICC = intraclass correlation coefficient; SJ: squat jump. No significant test-retest differences in each device, p > 0.05.