Inter-system and inter-unit reliability of Polar Team Pro and WIMU PRO devices during external load measurements indoors. - Rodríguez-Fernández, Alejandro; Suárez-Iglesias, David; Vaquera, Alejandro; Leicht, Anthony S; Rodríguez-Marroyo, José Antonio (Proceedings of the Institution of Mechanical Engineers -- Part P -- Journal of Sports Engineering & Technology, 2025)