Study aim: To examine the association between two submaximal (physical working capacity at a heart rate of 170 (PWC170) on cycle ergometer test and YMCA Step Test) and maximal measures (maximal oxygen uptake (VO2max)) of aerobic power, as well as to study the repeatability of the aforementioned submaximal measures in physically active female adolescents.Material and methods: Ten female adolescents, aged 13.4 ± 0.7 years old, all members of a local track and field sport club, performed the PWC170 and YMCA Step Test twice. The tests were separated by an interval of one week. During the second laboratory visit, VO2max was measured during a graded exercise test.Results: Considering the repeatability of submaximal measures, intraclass correlation coefficient was 0.89 (95% CI 0.55-0.97) and 0.91 (95% CI 0.65-0.98) in absolute and relative to body mass values of PWC170, while it was 0.69 (95% CI -0.27-0.92) with regard to heart rate at the end of step test and 0.78 (95% CI 0.11-0.95) at the end of the first minute of recovery after step test. PWC170 was associated significantly with VO2max in absolute values (r = 0.65, p = 0.04), but not with VO2max relative to body mass values (r = 0.44, p = 0.20). The corresponding relationships between relative PWC170 and VO2max were r = 0.39 (p = 0.27) and r = 0.60 (p = 0.06). Heart rate at the end of the step test was non-significantly related to VO2max in both absolute and relative values (r = -0.53, p = 0.12 and r = -0.61, p = 0.06), whereas respective values of heart rate at the end of the first minute after step test were r = -0.72 (p = 0.02) and r = -0.69 (p = 0.03).Conclusion: These submaximal measures appeared to be valid and reliable, and they were recommended for further use in similar population with the assumption that a familiarization session was preceded.