The FIET was developed by Barbero et al. with the aim to test Futsal players' ability to cope with high-intensity intermittent exercise. The test protocol was a consequence of match and time-motion analysis to support the logical validity of the FIET. The FIET consists of shuttle-running bouts of 45 m (i.e., 3 × 15 m) performed at progressive speeds until exhaustion dictated by prerecorded audio cues. Every 45-m, subjects are allowed to actively rest for 10 seconds. After each 8 × 45 m, bout players passively rest for 30 seconds before continuing. The starting speed is set at 9 km·h−1, and speed increments during the first 9 × 45-m bouts are of 0.33 km−1, successively shifting to 0.20 km·h−1 every 45 m until exhaustion.