BACKGROUND: The maintenance of maximal aerobic speed (MAS) until exhaustion is an important parameter for the evaluation of sports performance and prescription and planning of training. OBJECTIVE: To validate a 6-minute race test (6MRT) as a predictor of MAS in university endurance athletes. METHODS: Twenty two university endurance athletes (12 males and 10 females) were part of the study. The design was pre-experimental. The primary variables were the time of maintenance of the MAS on the field through a Time Limit Test (Tlim test), and the VO2 max (laboratory and field). The statistical analysis of the time and ventilatory variables was carried out using descriptive statistics; the comparison between males and females for all variables was carried out through a t-Student test for independent samples (p< 0.05). RESULTS: The performance in the Tlim test was 356.4 ± 52.9 and 327.0 ± 120.2 s in males and females, respectively. CONCLUSION: Based on the time of maintenance of the MAS (Tlim test), the 6MRT is a valid test to determine the MAS in university endurance male athletes. However, the MAS in university endurance female athletes must be evaluated with a shorter test (between 5 and 5.30 minutes long).