Effect Of High-intensity Interval Training On Blood Flow Shear Force In Postmenopausal Women

Objective: to compare the effects of high-intensity interval training and aerobic exercise in 8 weeks on cardiac function,hemodynamics and other functions of postmenopausal women,to explore the effect of high-intensity interval training on hemodynamics,and to analyze relevant factors,so as to provide theoretical and practical basis for high-intensity interval training to improve hemodynamics.Methods: in this study,28 postmenopausal female subjects were randomly divided into three groups: high-intensity interval training group;aerobic group;blank control group.High-intensity interval training with 85-95% maximum heart rate intensity exercise 4 minutes,interval 3 minutes,repeat 4 groups,3 times a week,a total of 8 weeks;The aerobic training group kept exercising for 30 minutes at the maximum heart rate intensity of 60-70%,3 times a week for 8 weeks.The maximum heart rate was determined by 207-(0.7 × age).The basic parameters and stroke volume,cardiac output,left ventricular end-diastolic volume,left ventricular end-systolic volume,blood flow shear force,blood flow velocity,resistance index,fluctuation index were measured in the quiet state before,4 weeks after,and 8 weeks after exercise.Repeated measures analysis of variance was used for each index before,during and after exercise in the group,and single-factor analysis of variance was used between groups.Spearman correlation analysis was used for blood flow shear force and cardiac function indexes as well as systolic and diastolic pressure.Results: There were no differences between the three groups measured before exercise.1.Changes in cardiac function: stroke volume(76.10 ± 4.53ml),cardiac output(5.10±0.63L),Volume(116.40±8.75ml)and left ventricular end-systolic volume(40.30 ± 5.76ml)were significantly higher than before exercise(54.00 ±6.27ml),(3.60±0.58L),(100.00±11.16ml),(46.00±6.77ml)(P<0.01)in high intensity intermittent group;Aerobic exercise group stroke output(68.00±10.50ml)after intervention was significantly higher than before exercise(55.63 ±14.22ml),cardiac output after intervention(4.54±0.52L),left ventricular end-diastolic volume(107.50 ± 12.33ml),the left ventricular end-systolic volume(39.50 ± 7.39ml)was significantly higher than before exercise(3.68±0.79L),(98.38±15.17ml),(42.75±7.03ml)(P<0.01);after 8 weeks of intervention,The stroke output(76.10±4.53ml)was significantly higher than that in aerobic exercise group(68.00±10.50ml)(P<0.05).The left ventricular end-diastolic volume(116.40 ± 8.75ml)and the left ventricular end-systolic volume(40.30 ± 5.76ml)were significantly higher in high intensity intermittent group than in aerobic exercise group(107.50 ± 12.33ml)and(39.50±7.39ml)(P<0.01).2.Hemodynamic changes: The blood flow shear force(19.31±0.94dynes/cm2)and blood flow velocity(70.10±2.30cm/s)were significantly higher in high intensity intermittent group than those before exercise(15.81±1.85dynes/cm2)and(57.41±4.89cm/s)(P<0.01);blood flow shear force(17.53±2.77dynes/cm2)and blood flow velocity(64.32±7.87cm/s)were significantly higher in aerobic exercise group than before intervention(15.71±2.68dynes/cm2)and(57.32±8.09cm/s)(P<0.01).After8 weeks of intervention,the blood flow velocity in high intensity intermittent group(70.10±2.30cm/s)was significantly higher than that in aerobic exercise group(64.32±7.87cm/s)(P<0.05).3.Correlation between blood flow shear force and cardiac function index: blood flow shear force is positively correlated with low stroke volume(r = 0.484,P <0.01);blood flow shear force and cardiac output are low The degree was positively correlated(r = 0.439,P <0.01);the blood flow shear force was moderately positively correlated with left ventricular end-diastolic volume(r = 0.514,P <0.01).Research conclusions:1.8 weeks of high-intensity interval training and aerobic exercise can effectively improve the pumping function of the heart of postmenopausal women.The effect of high-intensity interval training intervention is better than aerobic exercise;2.8 weeks of high-intensity interval training and aerobic exercise can effectively improve the blood flow shear force of postmenopausal women.The intervention effect of high-intensity interval training is better than aerobic exercise;3.8-week of exercise intervention may improve blood flow by improving stroke volume and left ventricular end-diastolic volume.