Application Of Heart Rate Variability In The National Women’s Boxing Team’s Pre-match Functional Status Monitoring For Major World Competitions

Objective:In this study,some morphological and physiological and biochemical indices were used to monitor the changes in physical functional status of boxers before the 2022 World Championships and to find the correlation between physiological and biochemical indices and training load,thus exploring the feasibility of heart rate variability as an important indicator to monitor physical functional status.Methods:(1)Study population:12 female athletes of the national boxing team preparing for the World Championships in Turkey(average age 26.08 ± 3.8 years,average height 170.5 ± 7.5 cm,average years of training 10.25 ± 2.8 years),8international fitters and 4 fitters.(2)Study protocol: In this study,12 athletes from the national boxing team preparing for the 12 th World Women’s Boxing Championship in Turkey in May 2022 were monitored for 12 weeks before the competition from2022.02.08 to 2022.05.06.HRV,routine physiological and biochemical and body fat percentage tests were performed in a quiet state during the recovery period after every2 weeks of training.HRV tests were performed in the evening during the recovery period;routine physiological and biochemical indexes(4ml of elbow venous blood was collected,including 2ml of EDTA anticoagulated whole blood and 2ml of sodium heparin anticoagulated whole blood)and body fat percentage tests were performed at6:30 am on the following Monday after the adjustment period after the training period in weeks 2,4,6,8,10 and 12.(3)Test indexes: 1)Morphological indexes:body fat percentage.2)Physiological indexes: morning pulse,heart rate variability(HRV)test indexes(SDNN,RMSSD,SDSD,Total power,HF,LF,LF/HF).3)Biochemical indexes: WBC,HB,BU,CK.Results:(1)Changes in some physiological and biochemical indexes of athletes during the pre-competition training period: During the 12-week preparation training,the HB level was significantly lower(p<0.05),the BU level was significantly higher(p<0.05),and the WBC,CK,and body fat percentage levels were lower(p > 0.05)than before the preparation training.(2)Changes of heart rate variability indexes during the pre-competition training period:1)Time-domain indexes: SDNN decreased compared with the basic value at the end of preparation training;SDSD and RMSSD increased compared with the basic value,and in general,SDNN,SDSD and RMSSD indexes were stable and showed high synchronization.2)Frequency-domain indexes:HF increased compared with the basic value at the end of preparation training;Total power,LF,HF,LF/HF decreased compared with the base value.(3)The correlation between load indexes and physiological and biochemical indexes during the preparation phase:1)training intensity: WBC and training intensity during the recovery period were negatively and significantly correlated(r=-0.314,p<0.01).2)training duration:WBC,HB and training duration were negatively and significantly correlated(r=-0.228,p<0.05;r=-0.24,p<0.05),BU,and morning pulse were significantly and positively correlated with training duration(r=0.189,p<0.05;r=0.211,p<0.05).(4)Correlation between training load indexes and heart rate variability indexes in the preparation phase:1)Time-domain indexes: RMSSD and SDSD had high synchronization and negative correlation with training intensity and training volume,with a significant negative correlation between training duration and RMSSD(r=-0.17,p<0.05).2)Frequency-domain indexes: In the frequency-domain indexes of heart rate variability in the preparation training,TP,HF,LF/HF and training duration showed positive correlations of different degrees,and LF and training duration showed negative correlations;Total power,HF and training intensity showed positive correlations of different degrees,and LF/HF,LF and training intensity showed negative correlations of different degrees.(5)Correlations between conventional physiological and biochemical indexes and heart rate variability indexes: 1)Time-domain indexes:SDNN,RMSSD and BU had significant positive correlations(r=0.35,p<0.01;r=0.35,p<0.01).2)Frequency-domain indexes:Total power had significant positive correlations with WBC and BU(r=0.36,p<0.05;r=0.14,p<0.01),and LF/HF had a significant negative correlation with BU(r=-0.36,p<0.01).Conclusions:(1)During the preparation period,the athletes’ physical function status showed a trend of decreasing first and then increasing,in which the athletes’ physical function status was more stable during the general preparation period and no obvious fatigue performance was seen;during the special preparation period,the training load increased significantly,the body sympathetic excitation and parasympathetic excitability decreased,and fatigue performance existed;during the last week before the competition,the autonomic function and physical function status improved significantly after the training load adjustment.(2)The changes of physiological and biochemical indexes are closely related to the fluctuation of training load,among which WBC can be used as a sensitive index of training intensity;WBC,HB,RMSSD,BU and morning pulse can be used as sensitive indexes of training volume.(3)The heart rate variability index and the blood index are in good agreement in the evaluation of athletes’ physical performance,so the heart rate variability index can be used as an important index for monitoring the physical performance of boxing athletes.