Twenty six football players of the Shandong Luneng youth team (U17), the 2019 season Chinese National Youth Super League champions. Based on a comprehensive assessment of the working capacity and func- tional support of intermittent endurance, the levels and changes in the reaction of the cardiorespiratory system and energy supply of football players’ activities were analyzed under the condition of fatigue cu- mulating in the process of performing a series of high-speed segments. The prerequisite for testing was the preservation of the parameters of running 70 m in 10 s during the entire testing period. Content of Cardiorespiratory System and Intermittent Endurance test: duration of work in a series – 4 minutes; dura- tion of work with the maximum available intensity – 10 s (running distance 70 m), rest interval – 20 s. The number of combinations of work segments 10 s and rest intervals 20 s in a series is 8. The efficiency of work is assessed by the number of completed series and the reaction of the cardiorespiratory system. The typo- logical differences in the functional support of the special working capacity of football players who had a high level of working capacity were determined. They are associated with a balanced type of aerobic and anaerobic energy supply, with an insignificant tension of the mechanisms for fatigue compensating and a predominantly anaerobic type of energy supply provided a high level of respiratory compensation for met- abolic acidosis.