Study On The Characteristics Of Heart Rate Variability Of Yang Jia Yu In Different Training Stages

Objective:To explore the characteristics of HRV changes of elite female race walkers in different training stages,explore the characteristics of sympathetic and pa rasympathetic nerves in autonomic nervous system in different training stages,and t ry to find the correlation between HRV and blood indexes and training impulse（T RIMP）of elite race walkers.Research methods:Taking Yang Jiayu,the world record holder of women’s 20 k m race walking,as the experimental object,the HRV was monitored during the prep aration for the Huangshan national race walking championship and Olympic trials i n March 2021,and its change characteristics,correlation with training impulse and b lood indexes were analyzed.Results:1)in the plain stage,SDNN,LF and VLF decreased first and then incre ased,with little overall fluctuation,LF/HF increased first,then decreased and then inc reased,RMSSD and HF showed a downward trend,and fluctuated greatly in the firs t four weeks;2)In the plateau stage,SDNN and RMSSD showed a gradual downw ard trend,HF was relatively stable,LF/HF showed a downward trend and fluctuated greatly in the early stage,and LF and VLF showed an upward trend and fluctuate d greatly.Compared with the plain stage,RMSSD and HF decreased（P<0.01）,SDN N decreased（P<0.05）and LF increased（P<0.01）;3)In the pre competition stage,co mpared with the plateau stage,RMSSD,SDNN,HF,LF and VLF first increased and t hen decreased to lower than that before the plateau training.SDNN decreased com pared with the plateau stage（P<0.01）,and LF/HF decreased compared with the plat eau stage（P<0.05）;4)SDNN and LF were significantly negatively correlated with t raining load（P<0.01）,RMSSD and VLF were significantly negatively correlated wit h training load（P<0.05）;5)RMSSD,SDNN and HF were negatively correlated with blood index HB（P<0.05）,and the correlation between other HRV indexes and blo od indexes was not statistically significant.Research conclusions:1)training fatigue in plain stage leads to the increasing trend of sympathetic nerve activity and the decreasing trend of vagus nerve activit y,but the balance ability of autonomic nervous system is greatly improved;2)At hi gh altitude,with the increase of training load,HRV index decreased,sympathetic ner vous system activity increased,vagus nerve activity decreased,LF and VLF were mo re sensitive to exercise fatigue;3)HRV index decreased in the pre competition stag e,and the lowest one week before the competition;4)Routine blood index monitor ing combined with HRV index monitoring can more comprehensively understand th e physical function of athletes and provide more accurate reference for coaches.