Design, Construction, and Reliability of a Native Electronic Device (EPIF) to Measure the Young Futsalists’ Endurance Performance

Quick and accurate assessment of cardiorespiratory capacity is very important in research and exercise conditions. Therefore, the design and evaluation of cheap, light, and portable devices are worthy of consideration. FFThis study investigated the reliability of endurance performance indices in Futsal (EPIF) during the implementation of two selected field tests (FIET = Futsal intermittent endurance test and TCAR = Carminatti test). 23 futsal players with playing experience of 7.2 ± 2.1 years, an average age of19.1 ± 3.07 years, and a body mass index of 21.20 ± 1.04 kg/m2, were randomly selected. They first voluntarily performed the FIET test and then the TCAR test with an interval of 3 days. To evaluate the validity and reliability of the TCAR field test, the researchers used Pearson's correlation coefficient and intra-class intragroup correlation (ICC), respectively. A significant correlation was found between the physiological variable of final heart rate (HR) and the HR delta of running activity in the FIET test, with VO2 max using the standard method. The reliability of the FIET test was reported at an excellent level (p < 0.001, ICC = 0.912-0.939). Also, after the field tests, the HR delta was reported as a suitable predictive factor for estimating the VO2 max of young futsal players (p = 0.020, SEE = 4.051, R2 = 0.512). The findings show the high reliability and validity of the TCAR field test with the EPIF device. Therefore, the design and construction of this native device and its use for coaches at the club and national levels are worthy for evaluating the athletic endurance of futsal players.