Abstract: Objective: To analyze the relationship between SMO₂ and HR and BLA during recovery after high-intensity interval training so as to explore the relationship between SMO₂ and HR and BLA during recovery after high-intensity interval training and provide a better application of SMO₂ indicator to monitor and evaluate the recovery of human body after high-intensity interval training. Methods: Fifty male students (age 21.65 ± 1.04 yrs; height 174.95 ± 5.47 cm; weight 73.35 ± 7.5 kg) were selected as the test subjects to complete 3x30s full-strength high-intensity interval trainings, and their SMO₂ and HR, BLA indicators were collected during exercise and 20 min after exercise. Using SPSS 21.0 statistical software for data analysis, and using the variance analysis of repeated measurements to do the variance test of HR, BLA and SMO₂ at different time points. Using Pearson correlation analysis for the correlation analysis between MO₂ and HR and BLA during recovery. Result: After high-intensity interval training, SMO₂ recovery rate reached 100% at 35 s, the recovery showed a sharp rise in a short period of time, followed by the time-phase characteristic of "excessive recovery"; HR recovery presents the time-phase characteristic of being fast at first and then slowing down. The changes of HR and SMO₂ were highly correlated within 1 min, then the correlation decreased gradually. There was no correlation between the changes of HR and SMO₂ after 15 min. The concentration of BLA showed the characteristic of increasing first and then decreasing. It reached the peak value in 3 min, then decreased slowly. The change of BLA and that of SMO₂ were basically not related during the 20 min recovery period. Conclusion: After high-intensity interval training, the recovery of SMO₂, HR and BLA present metachronous feature. The recovery rate of SMO₂ is the fastest, followed by HR, and the slowest is BLA. After high-intensity interval exercise, the recovery rate of SMO₂, HR and BLA reflects the various aspects of the overall aerobic capacity of the organism, and they interact with and promote each other.

Key words: high-intensity interval training, SMO₂, HR, BLA