Effect Of Hyperbaric Oxygen Intervention On Microcirculation Function And The Elimination Effect Of Exercise-induced Fatigue Of National Steel Frame Snowmobile Athletes

AbstractResearch objectiveMicrocirculation is the only place where substances,energy and information are exchanged and transmitted between blood and cells,playing an important role in maintaining normal physiological functions of the human body.High intensity training can lead to microcirculation dysfunction in the body,reduce the level of cellular material and energy metabolism,and then induce exercise-induced fatigue.Some studies have pointed out that hyperbaric oxygen（HBO）intervention can improve microcirculation dysfunction and promote the elimination of exercise-induced fatigue.However,the relationship between microcirculation function and exercise-induced fatigue is mainly described qualitatively and theoretically,and there are few quantitative correlation studies involving the them.Especially,there are no reports of practical studies in high-level athletes and preparedness training.Therefore,further research is needed to determine whether HBO intervention can promote fatigue elimination by improving training induced microcirculation dysfunction.As one of the winter skiing and racing events,the steel frame snowmobile is a key project in China’s preparation for the 2022 Winter Olympics.Its training is mainly divided into summer specific physical fitness and winter track skiing training.High intensity training loads and special training environments can easily cause microcirculation dysfunction in athletes,leading to exercise-induced fatigue.Therefore,the purpose of this study is to conduct a single and long-term repeated HBO intervention on national steel frame snowmobile athletes during the summer and winter training stages,respectively,to observe the intervention effect of HBO on the microcirculation function and the elimination effect of exercise-induced fatigue of athletes,and to study the correlation between the two to clarify the correlation between the microcirculation function and exercise-induced fatigue.In addition,this study will also explore the possible mechanism of HBO changing the microcirculation function of athletes from the perspective of hematological indicators.Research methodThe research focuses on the national steel frame snowmobile athletes preparing for the 2022 Beijing Winter Olympics,with two aspects of research content.（1）Research content 1:Study on the effect of single HBO intervention on microcirculation function and the elimination effect of exercise-induced fatigue of athletesSixteen national steel frame snowmobile athletes were divided into an intervention group and a control group.On the Sunday of the regular training week during the summer and winter training stages,the intervention group athletes were given a 60 minute 1.3ATA-HBO intervention.Athletes in the control group received natural recovery rest.Before and after the experiment,the indicators of microcirculation function and exercise-induced fatigue,and analyze the correlation between microcirculation function indicators and exercise fatigue-induced indicators.In addition,the exercise-induced fatigue indicators was tested again the next morning.The indicators of microcirculation function include microcirculation blood perfusion（MBP）,microvascular reactivity（MR）,transcutaneous partial pressure of oxygen（Tc PO₂）,and muscle oxygen saturation（Sm O₂）.MBP and MR were evaluated using two methods:local heating hyperemia（LTH）and post-occlusion reactive hyperaemia（PORH）.Exercise-induced fatigue indicators include blood urea（BU）,creatine kinase（CK）,heart rate（HR）,rating of perceived exertion（RPE）,and comprehensive diagnostic indicators of athletic status.（2）Research Content 2:The effect of 4-week HBO intervention on microcirculation function and the elimination effect of exercise-induced fatigue of athletesFour weeks were selected as the research phase during the summer and winter training stages,respectively.The national steel frame snowmobile athletes were divided into an intervention group and a control group.During the non-training rest period,the intervention group athletes were given 60 minutes of 1.3ATA-HBO intervention（4 times per week,lasting for 4 weeks）,while the control group athletes were received natural recovery rest.Before the start of the experiment（before the experiment）,after the end of two weeks of training（during the experiment）,and after the end of four weeks of training（after the experiment）,the microcirculation function indicators,exercise-induced fatigue indicators,and sports performance of the two groups of athletes were tested,and the correlation between the microcirculation function indicators and exercise-induced fatigue indicators was analyzed.In addition,this section will also explore the possible mechanism of HBO intervention to change the microcirculation function of athletes.Microcirculation function indicators are the same as research content 1.Exercise-induced fatigue indicators include BU,CK,testosterone（T）,cortisol（C）,hemoglobin（Hb）,HR,RPE,Immunoglobulin A（Ig A）,Immunoglobulin G（Ig G）,Immunoglobulin M（Ig M）,Interleukin-6（IL-6）,Interleukin-10（IL-10）,tumor necrosis factor-a（TNF-a）,C-reactive protein（CRP）,Serum creatinine（SC）,blood uric acid（BUA）,cysteine protease inhibitor C（Cys-C）The mechanism indicators are nitric oxide（NO）,endothelin 1（ET-1）,vascular endothelial growth factor,malondialdehyde（MDA）,protein carboxyl（PC）,catalase（CAT）,superoxide dismutase（SOD）and adrenalin（E）,norepinephrine（NE）,angiotensin 1-7（Ang1-7）,angiotensin 2（Ang2）.Research resultsResearch content 1:（1）Microcirculation function indicators:After summer and winter training,the forearm MBP reserve capacity（LTH）and MR（LTH）in the intervention group were significantly higher than before the test（P<0.05）,and the thigh MBP reserve capacity（LTH）and MR（LTH）were significantly higher than before the test（P<0.01）.After the winter training intervention group experiment,the MBP reserve capacity（LTH）and MR（LTH）were significantly higher than before the experiment（P<0.01）,and MR（LTH）was significantly higher than the control group（P<0.05）.After the summer and winter training experiments,the MR（PORH）of the intervention group was significantly higher than before the experiment（P<0.05）and the control group（P<0.05）.After the summer and winter training tests,the Tc PO₂in the forearm and thigh of the intervention group was significantly higher than before the test（P<0.01）,and the winter training was significantly higher than the control group（P<0.01）.After the summer training experiment,the Sm O₂in the forearm and thighs of the intervention group was significantly higher than before the experiment（P<0.05）,and the thighs were significantly higher than the control group（P<0.05）.（2）Sports fatigue monitoring indicators:The HR of the summer training intervention group was significantly lower after the experiment and on the second day than before the experiment（P<0.05）;On the second day,the score of central nervous system function in the intervention group was significantly higher than that before the test（P<0.01）and the control group（P<0.05）,and the score of comprehensive readiness was significantly higher than that before the test（P<0.05）and the control group（P<0.01）;After the experiment and on the second day,the RPE in the control group was significantly higher than that in the intervention group（P<0.01,P<0.05）.The central nervous system function score of the winter training intervention group on the second day was significantly higher than before the experiment（P<0.01）and the control group（P<0.05）.The comprehensive readiness score of the intervention group after the experiment and in the morning on the second day was significantly higher than the control group（P<0.01）,and the RPE of the intervention group on the second day was significantly lower than before the experiment（P<0.05）.（3）Correlation between the two:There is a moderate correlation between microcirculation indicators and exercise fatigue monitoring indicators.Research content 2:（1）Microcirculatory function indicators:After the summer training experiment,the intervention group’s forearm MBP reserve capacity（LTH）was significantly higher than before the experiment（P<0.01）and the control group（P<0.01）,while the thigh MBP reserve capacity（LTH）was significantly higher than the control group（P<0.05）.After the winter training test,the thigh MBP reserve capacity（LTH）and MR（LTH）in the intervention group were significantly higher than those before the test（P<0.05）and in the control group（P<0.05）.After the summer training test,the MBP reserve capacity（PORH）of the intervention group was significantly higher than that of the pre test（P<0.01）and control group（P<0.01）.After the experiment,Tc PO₂and Sm O₂in the forearm of the summer and winter training intervention groups were significantly higher than those before the experiment（P<0.05）,while Tc PO₂in the thigh was significantly higher than those before the experiment（P<0.01）and the control group（P<0.01）.Sm O₂in the thigh was significantly higher than those before the experiment（P<0.05）and the control group（P<0.05）.（2）Monitoring indicators of exercise fatigue:After the winter training test,the BU in the control group was significantly higher than that in the intervention group（P<0.05）,while after the summer training test,the CK in the control group was significantly higher than that in the intervention group（P<0.05）.After the winter training test,the T/C in the intervention group was significantly higher than that before the test（P<0.05）and in the control group（P<0.05）.After the summer training test,the NE in the control group was significantly lower than that before the test（P<0.01）,the Ig G in the intervention group was significantly higher than that in the control group（P<0.05）,and the CRP in the control group was significantly higher than that before the test（P<0.05）and in the intervention group（P<0.05）.The TNF-a and CRP levels in the winter training control group were significantly higher after the experiment than before（P<0.05）,and TNF-a levels were significantly higher than those in the intervention group（P<0.05）.After the summer training test,ALT in the control group was significantly higher than that before the test（P<0.05）and in the intervention group（P<0.05）,while CYS-C in the intervention group was significantly lower than that before the test（P<0.05）and in the control group（P<0.05）.After the winter training intervention group experiment,the CYS-C was significantly lower than before the experiment（P<0.05）and the control group（P<0.05）.After the summer training test,the central nervous system function score and comprehensive readiness score of the intervention group were significantly higher than those of the control group（P<0.05）,the HR of the control group was significantly higher than those before the test（P<0.05）and the intervention group（P<0.05）,and the RPE of the control group was significantly higher than those before the test（P<0.05）and the intervention group（P<0.01）.After the winter training experiment,the central nervous system function score of the intervention group was significantly higher than that of the control group（P<0.01）,and the comprehensive readiness score of the intervention group was significantly higher than before the experiment（P<0.05）and the control group（P<0.05）.In the control group experiment,HR was significantly higher than before the experiment（P<0.01）and the intervention group（P<0.05）.（3）Correlation between the two:There is a moderate correlation between microcirculation indicators and key monitoring indicators of exercise-induced fatigue,and the correlation between lower limb Tc PO₂,Sm O₂and key monitoring indicators of exercise-induced fatigue is higher.（4）Sports performance indicators:After the summer and winter training experiments,the improvement of various sports performance indicators in the intervention group was greater than that in the control group,but there was no significant difference（P>0.05）.（5）Indicators of mechanism of microcirculation function:After the experiment,the NO in the summer training and winter training intervention groups was significantly higher than that before the experiment（P<0.05）and the control group（P<0.05）,and the NO/ET-1 in the winter training control group was significantly lower than that before the experiment（P<0.05）and the control group（P<0.05）.After summer and winter training,the VEGF in the intervention group was significantly higher than that in the control group（P<0.05）.After the summer training intervention group,the MDA and PC were significantly lower than those before the test（P<0.05）and in the control group（P<0.05）,while after the winter training experiment,the MDA and PC in the control group were significantly higher than those in the intervention group（P<0.05）.After the summer training experiment,the SOD and CAT in the intervention group were significantly higher than those before the experiment（P<0.01）and the control group（P<0.01）,while after the winter training experiment,the SOD in the intervention group was significantly higher than those before the experiment（P<0.05）.There were no significant changes in E,NE,Ang（1-7）,Ang-2,Ang（1-7）/Ang-2 between the two groups during summer training and winter training（P>0.05）.Research conclusion（1）A single 60-minute 1.3ATA-HBO intervention can improve the microcirculation function of the national steel frame snowmobile athletes,promote the elimination of athletes’fatigue,and show better results in the morning of the next day.In addition,the intervention effect of single HBO on exercise-induced fatigue in winter training stage is better than that in summer training stage.（2）The high-intensity special physical training for 4 weeks of summer training reduced the microcirculation of forearm and thigh of athletes,while the track sliding training for 4 weeks of winter training reduced the microcirculation of thigh of athletes,and the 1.3ATA-HBO recovery intervention for 4 weeks can improve the microcirculation function of athletes and improve the microcirculation function disorder.（3）The four-week special physical training and track sliding training both make the steel frame snowmobile athletes produce sports fatigue,and the fatigue level of athletes in summer training stage is deeper.The four-week 1.3ATA-HBO recovery intervention can promote the elimination of sports fatigue and improve sports performance.（4）HBO intervention to promote the elimination of exercise-induced fatigue is related to the changes of microcirculation function of athletes,and improving microcirculation function may be one of the ways to promote the elimination of exercise-induced fatigue.In addition,4-week HBO intervention may improve the microcirculation function of athletes by regulating the level of NO/ET-1,promoting the expression of VEGF,and improving the function of oxidation-oxidation system.