Continuous tests performed on standardized ergometers are not specific enough for football. Probst\u2019s test at intervals allows the assessment of the maximal aerobic velocity (VMA) and the anaerobic threshold (UAn) on the football ground, there are not reference data available. Such parameters are intended to be assessed on Spanish footballers in order to check its sensitivity to the level of expertise and its utility in determinating the UAn. Two hundred and thirty-one football players from junior (n = 26), amateur (n = 74), semiprofessional (n = 36) and professional (n = 95) categories participated in this study and had their velocities and Fc at UAn manually and mathematically determinated (UAnI and UAnM respectively). There existed an inflexion of the Fc in more than the 89 % of the tests. The Fc at the UAn was similar to those described in the literature (90-95 % with respect to the maximal) and the velocity at UAn obtained wide VMA ranges (72-96 %). The test was sensitive to the level of expertise for the UAnI and VMA variables. The protocol of Probst\u2019s tests at intervals allowed to carry out a specific field test sensitive to the degree of professionalization among football players, establishing reference data for the categories studied. The Fc analysis allowed the identification of an inflexion point that might correspond the UAn.<\/p>\n