Influence of the time-task constraint on ocular metrics of semi-elite soccer players.

This study novelty aimed to investigate the influence of manipulating the available time to perform the training tasks on soccer players´ ocular metrics, following training. Specifically, pupillary response (pupil diameter) and saccadic features (latency, accuracy, velocity, and number) were measured with a portable eye tracker following training to reflect the mental load accumulated by players during the training sessions. Nine semi-elite soccer players performed two training sessions, based on large-sided games, on an artificial grass field. These two sessions were composed of the same tasks but varying the required time to complete the task goals (Session 1: No time limitations to perform the tasks; Session 2: Limited time to perform the tasks). The participants performed, before (pre-test) and after (post-test) each training session, a prosaccade task in a room near the playing field. Findings revealed a differentiated effect of the available time to complete the training tasks on ocular metrics because significant differences were found in all variables after training (p < .001 for pupil diameter; p < .01 for saccade accuracy and number of saccades; p < .05 for saccade velocity and latency). Ocular metrics could be a promising tool to evaluate mental load following practice because they were sensitive to the time-task constraint, providing researchers a valuable information for a better planning of the mental workload when designed training tasks.