Research On Monitoring Pre-Competition Stage And Indicators Change Of National Snowboard Halfpipe Team

Purposes: As one of the winter Olympic events,snowboarding u-shaped field event has developed well in China in recent years and has become one of the gold medal winning events in the winter Olympic Games.Due to its great ornamental value and driven by the ice and snow craze caused by the 2022 Beijing winter Olympics,this project has attracted extensive attention from the society and media.The implementation of physical function monitoring for athletes can enable coaches to understand the physical function of athletes from the perspective of physiology and biochemistry,and provide scientific and technological assistance for the preparation for the winter Olympics.By collecting and analyzing the changes of heart rate variability index and physiological and biochemical index of snowboarding u-shaped field athletes,this paper finds out the characteristics of the changes of each index and the relationship between each index in different training weeks,and explores the rules between exercise load arrangement and physiological and biochemical index.Methods: By tracking record 13 Chinese snowboarding u-shaped ground national team athletes in different weeks training intensity and land stage of training load,and use the Omega Wave function evaluation index system for routine blood and blood instrument(including testosterone(T),cortisol(C),creatine kinase(CK),blood urea(BU),hemoglobin(HB),white blood cell(WBC)and heart rate variability index(including time domain index SDNN,RMSSD,PNN50 frequency domain and time domain index of HF,LF,TP)of the collection and analysis.Results:(1)The variation characteristics of biochemical indexes in different training stages: During the five-week training,both male and female athletes,T,C,CK and BU all increased in the second week and decreased in the third and fourth weeks,wherein CK showed a significant difference in the change process in the third week(P<0.05),while HB showed an opposite trend of decreasing first and then increasing in the second week.However,there was no significant difference in other indicators.(2)The variation characteristics of heart rate variability indicators in different training stages: At different training intensity weeks,there was no significant difference in the change of time-domain index of heart rate variability,but both male and female athletes showed a trend of decreasing first and then increasing,slowly increasing from the third week and gradually slowing down in the later period.The variation is even greater for female athletes.(3)The correlation analysis of biochemical indicators and heart rate variability indicators: HF,LF and C,frequency indexes of heart rate variability,have a significant negative correlation(P < 0.05).The correlation coefficients are-0.28 and-0.258,respectively.HF and BU have a significant negative correlation(P < 0.05).No correlation was found between other indicators(P > 0.05).The time domain indexes SDNN,RMSSD,PNN50 of heart rate variability of athletes were significantly negatively correlated with routine blood indexes BU(P < 0.05).The correlations were-0.521,-0.255,-0.278,respectively,and were significantly negatively correlated with C(P < 0.05).The correlations were-0.430,-0.255,-0.276,respectively.The time domain index SDNN was significantly negatively correlated with the blood index CK(P < 0.05),and the correlation coefficients were-0.274.No correlation was found between the other indicators(P > 0.05).Conclusions: During the five-week training,athletes show a certain change trend in the changes of biochemical indexes and HRV indexes,indicating that the change of training load has a certain stimulating effect on the body,and the load arrangement is relatively reasonable.Among them,the change of CK value is the most obvious,which can be used as a sensitive indicator of training monitoring in this project.In addition,the change of HRV and the change of the normal functional status evaluation index showed good consistency,which indicate HRV index as a function of noninvasive monitoring index can more accurately reflect the snowboarding u-shaped venue project athlete's response to the training load and to adapt to the situation,as the body function monitoring indicators.