“…In studies on the determination of HR max in team sports, several maximal physical tests have been used, i.e., laboratory tests on the treadmill 10,15,16 ; continuous running field tests 9,11 and intermittent running field tests 8,12,15,16 , which have ecological validity, as for example, the Yo-Yo intermittent recovery level 1 test (YYIR-1), a test with high reproducibility, sensitivity, validity to access HR max , indicate to intermittent sports 15 . However, the HR max determined in soccer official matches 7,11,12 and basketball simulated match 17 has shown higher values in comparison to physical tests, while only one study with futsal players reported similarity between match and physical test HR max 18 . Although HR measured at maximal physical exertion is more trustworthy in establishing HR max , a better way to determine HR max , in the absence of equipment to determine the HR max at maximum effort, the use of agepredicted equations should be cautious, considering that there are many age-predicted HR max equations validated for distinct populations 9,16,17 , and the use of general agepredicted equations may generate an important prediction error when utilized in specific sports, jeopardizing training prescription 3,17 .…”