Study On Mechanism Responsible For Effect Of HiHiLo And Altitude Training On The Cutaneous Microcirculation Function In Rowers

Objectives:By testing the microcirculation of rowing athletes before and after intervention,the effects of 4-week living high training high and low and 8-week altitude training on the cutaneous microcirculation function of rowing athletes were discussed respectively;To explore the microvascular mechanism of the influence of 4-week living high training high and low and 8-week high altitude training on cutaneous microcirculation function;To explore the relationship between the changes of cutaneous microcirculation function and aerobic capacity caused by living high training high and low and altitude training,respectively.Materials and methods:This study includes two experiments,which were approved by the ethics committee of Shanghai university of sport?102772019RT033?.?1?Participants:Experiment 1.Participants:24 male rowers from Shanghai rowing team were divided into living high training high and low group?HHL,12?and normoxia training group?NOM,12?.Study methods:all athletes trained for 4 weeks.The HHL group trained and lived in a hypoxic environment for 6 days per week?2500-3000 m?.Experiment 2.Participants:36 male rowers from Shanghai rowing team were recruited to participate in this experiment and were divided into two groups:plateau training group?AT,18?and plain training group?ST,18?.Methods:subjects completed an 8-week plateau or plain training program.Group AT lived and trained on the plateau?2,280 m,low pressure and hypoxia,huize,yunnan?,while group ST lived and trained on the plain?50 m,hangzhou,zhejiang?.?2?Test indicators:microcirculation function,including blood flow,mobile blood cell concentration,blood flow velocity,percutaneous oxygen partial pressure,etc.VO_2peak;P₄.6km special movement capacity of dynamometer;Hematological indicators,including white blood cells,HIF,NO,VEGF,EPO,ET.Sport performance were tested for 2 times before and after the intervention,and microcirculation and hematological indicators were tested for 4 times before and after the intervention.Results:?1?Sport performance results:The VO_2peak of NOM group increased slightly?4984.9±498.3 vs.5134.8±788.3 ml/min?,p=0.677,and P₄ showed a similar trend.Results of experiment 2 show that VO_2peak has interaction effect of time and group,p<0.01.In the AT group,VO_2peak increased by 8.8%after intervention?4708.9±455.2VS 5123.3±391.2 ml/min,p<0.01?.The ST group showed a 3.1%increase,but no significant difference?4975.4±501.1 vs.5128.0±499.3 ml/min,p=0.125?.RVO_2peak also has the interaction effect of time and group?p<0.01?.RVO_2peak of AT group was significantly increased after intervention?58.9±4.9 vs.66.0±5.1 ml/min/kg,p<0.01?,while ST did not significantly increase after intervention?61.3±7.4 vs.62.8±7.4ml/min/kg,p=0.217?.The ergometer 5km performance of AT group was significantly improved after intervention?1040.3±26.3 VS 1033.2±27.5 seconds,p=0.038?.?2?Cutaneous microcirculation function results:By repeated measurements of the mixed model analysis,SpO₂,upper limb CMBC,Heat,and transcutaneous oxygen partial pressure?TcPO₂?showed significant differences between the groups?P<0.01?.Non-parametric test results of paired samples showed that the blood flow and CMBC in the HHL group were significantly increased in the first week?8.9?7.0,12.8?vs.13.0?8.0,15.0?PU,p<0.05?.112.0?75.3,142.0?vs.151.0?105.0,159.0?,p<0.05),but recovered to the pre-intervention value after intervention.The upper limb PORH reserve in the AT group increased significantly after 8 weeks of training?3.6?3.2,4.3?vs.4.6?3.9,6.8?,p<0.05?.PORH maximum blood flow increased after intervention?44.5?35.0,60.0?vs.54.0?38.0,83.5?PU,0.05<p<0.1?.AT the same time,the basal blood flow,CMBC and CVC of the thigh in the AT group were also higher than those before the intervention,but there was no significant difference.However,TcPO₂,CMBC and CVC of ST group significantly decreased after 8 weeks of training.The change of VO2peak before and after plateau training was positively correlated with the change of thigh blood flow?week 6 vs.baseline?,r=0.45,p=0.01,and was positively correlated with the change of thigh CVC?week 6 vs.baseline?,r=0.43,p=0.01.?3?Hematological mechanism results:Compared with the base values,EPO and HIF in the HHL group increased in the second week?10.4?8.8,13.1?vs.12.7?10.1,13.5?mIU/ml;27.0?19.8,66.4?vs.27.7?15.4,75.5?pg/ml,p>0.05?,and HIF increased at week4?27.0?19.8,66.4?vs.31.1?25.4,66.2?pg/ml,0.05<p<0.1?.NO level in HHL group increased significantly at week 4?0.05?0.04,0.15?vs.0.08?0.06,0.14?mol/l,p<0.05?,but eNOS did not show any significant difference at week 4.At week 4 and after the intervention,VEGF level in the HHL group was higher than the baseline?0.05<p<0.1?.In the HHL group,MDA decreased significantly?0.66?0.47,1.50?vs.0.43?0.35,0.94?,0.66?0.47,1.50?vs.0.50?0.33,0.90?nmol/l,p<0.05?at the 4th week of intervention and after intervention compared with the basic value?0.66 VS 0.43,0.66 VS 0.50 nmol/l,p<0.05?;in the HHL group,ROS increased at the 2nd week of intervention,but there was no significant difference?43.3?25.6,146.9?vs.46.8?25.0,135.8?IU/ml,p>0.05?;in the HHL group,SOD increased after intervention?11.9?6.9,42.3?vs.12.9?9.9,24.6?U/mol,0.05<p<0.1?.In the NOM group,MDA significantly decreased at week 4 and after intervention?0.98?0.65,2.31?vs.0.54?0.34,1.56?nmol/,p<0.05?,and SOD significantly decreased at week 2?24.2?13.1,61.6?vs.17.5?9.7,42.4?U/ml,p<0.05?.NO and eNOS were significantly increased in the AT group after intervention?0.05?0.04,0.09?vs.0.10?0.05,0.20?mol/l,p<0.05?.2.2?1.3,3.4?vs.3.7?2.0,7.8?IU/ml,p<0.05).ET in the AT group increased significantly in the third week,6.0?4.2,9.9?vs.10.1?5.0,15.6?ng/ml,p<0.05,and 6.0?4.2,9.9?vs.9.5?5.0,15.6?pg/ml,p<0.05,before intervention was still significant after intervention.PGI2 in the AT group was significantly higher after intervention than before,7.4?3.9,12.4?vs.12.1?6.8,22.7?mIU/ml,p<0.05.VEGF of AT group increased significantly during the intervention.Conclusions:?1?Four weeks of HiHiLo and eight weeks of altitude training can significantly improve the peak oxygen uptake of rowing athletes,but eight weeks of altitude training can also improve the rowing athletes'ergometer 5 km performance;?2?Four weeks of HiHiLo only increased the blood flow in the forearm of rowers,while eight weeks of high altitude training significantly increased the blood flow in the thigh and endothelial function of rowers,which may be related to the significant increase in nitric oxide and vascular endothelial growth factor of rowers;?3?There is a certain correlation between the improvement of cutaneous microcirculation function and the change of aerobic capacity of rowers after 8-week altitude training,and the improvement of cutaneous microcirculation function may be one of the mechanisms for the improvement of sports performance.