This investigation work is funded by FCT/MCTES through national funds and, when applicable, co-financed by the EU under the UIDB/50008/2020 project. It is part of the Post-Doctorate of Francisco Campos entitled “The Eye Tracking System for analysis of visual patterns of the fitness instructors in group exercise activities”, developed at the Instituto de Telecomunicações—Delegação da Covilhã (Portugal). Also received support from the Institute of Applied Research (i2A) of the Polytechnic of Coimbra, under the exemption for Applied Research (Despacho nº 7333/2020), and from the Research Unit in Applied Sports Sciences (ASSERT) from the Education School of the Polytechnic of Coimbra. The acquisition of the instruments was funded by CIDAF (uid/04213/2020).