Effects Of Swimming Training Intervention On Body Morphology And Vascular Function In Obese People

Objective:In order to explore exercise methods suitable for overweight/obese people,help overweight/obese people to improve their body shapeimprove aerobic capacity and cardiorespiratory fitness(CRF)to reduce the incidence of related cardiovascular diseases(CVD),and compare the different effects of HIIT and MICT training methods in water.This study discussed the influence of 8-week swimming training intervention on the improvement of body shape of obese and overweight people and the feasible mechanism,and provided scientific suggestions and programs for obese and overweight people and the general public to promote the development of body shape and cardiovascular health through swimming.Methods:Forty-one,overweight/obesepeople(BMI>25kg/m2)wereecruite from Guangzhou Institute of Physical Education.The average age of the subjects was 23±4 years old,including 9 females and 32 males with a mean BMI of 27.3±2.0kg/m2.They were randomly divided into 2 groups: 21 participants in the high intensity interval training group(HIIT group)and 20 participants in the medium intensity continuous training group(MICT group).HIIT group and MICT group received 60 minutes of exercise intervention 3 times a week for 8 weeks at the same time.The HIIT group performed30 seconds *12 sets of sprint swim with exercise intensity of 90%-95% HRmax,with60 seconds of rest between each group.The MICT group swam nonstop for 30 minutes using 70%-75% HRmax.Before and after exercise intervention,Inbody370 was used to test the body composition of the subjects.Carotid femoral pulse wave conduction velocity(cf PWV)and brachial-ankle pulse wave conduction velocity(ba PWV)were used as indicators to evaluate the peripheral artery stiffness.Brachial artery flow-mediated vasodilation response(FMD)was measured using the non-invasive ultrasound UNEXEF38 G system,maximal oxygen uptake was measured using the power bicycle experiment Master Screen CPX,and serum samples were taken to detect blood factors associated with vascular function.Results:The results of the body composition test show that: Both groups could effectively reduce body weight and BMI,but HIIT group was better than MICT group in body weight(P<0.01),BMI(P<0.01)and body fat percentage(P<0.001),and HIIT group showed a significant increase in skeletal muscle compared with MICT group(P=0.05).The chest circumference(P<0.05),waist circumference(P < 0.05),arm circumference(P<0.05)and leg circumference(P<0.001)in HIIT group were significantly,decreased,while,thehipcircumference(P<0.05),arm circumference(P<0.05)and leg circumference(P<0.05)in MICT group were significantly decreased.(2)The results of cardiovascular function test showed that both HIIT group(P<0.001)and MICT group(P<0.05)could improve FMD of subjects,but the improvement of FMD in HIIT group was more obvious.Before and after intervention,cf PWV and ba PWV did not change significantly in both groups,but resting heart rate decreased significantly in the MICT group(P<0.05).(3)VO2max in HIIT group increased from32.1±5.73 to 33.0±5.92,P<0.01,while MICT showed no significant difference before and after intervention.Conclusion:Both HIIT and MICT swimming interventions at 8 weeks significantly improved body composition and vascular endothelial function in overweight/obese people,but had no significant effect on peripheral arterial stiffness.However,even with the same exercise items,different exercise modes have different effects on the segmental body composition,VO2 max,FMD and resting heart rate of overweight/obese people.