Effects Of Accumulated Exercise On The Stiffness And Hemodynamics Of Common Carotid Artery

Objective: To compare the effects of moderate intensity aerobic exercise on the stiffness and hemodynamic parameters of common carotid artery by continuous exercise and accumulated exercise,and to observe the recovery of blood flow and vascular acute response after exercise.The effects of exercise on cardiovascular health were evaluated from the aspects of arterial stiffness and hemodynamics.To provide the basis for formulating exercise prescription and selecting the best exercise pattern;It provides some reference for further selection and formulation of reasonable exercise pattern to further study the effect of long-term exercise on the structure and function of arteries.Methods: 30 healthy adult male volunteers without long-term regular exercise habits were recruited(Age: 18.76±1.81 years old;Height: 173.42±6.14 cm;Weight: 61.69±6.30 kg;Body mass index: 20.56±2.30).Each subject was required to complete four experimental interventions.To ensure that each experiment is not influenced by the results of the previous experiment,there should be at least one week between each experiment.The intervention consisted of a control group and three exercise interventions groups The exercise intervention required 30 minutes of moderate-intensity cycling with continuous exercise(CE: 1×30minutes)and two accumulaterd exercise modes by 10-minute one bout(AE15: 2×15 minutes;AE10: 3×10 minutes).Before and immediately after exercise,at 10 minutes and 20 minutes,color Doppler ultrasound was used to collect the center-line velocity and diameter waveforms of the common carotid artery.Synchronously,electronic sphygmomanometer was used to measure heart rate and blood pressure at the brachial artery.Results:(1)Immediately after exercise,the arterial stiffness index and pressure-strain elastic modulus of the CE and AE15 groups increased significantly.However,there was no significant difference from that of AE10 group.Arterial diameters decreased in both accumulated exercise groups,but there was no significant difference from the continuous exercise pattern.After lying for 10 and 20 minutes,the arterial stiffness index,pressure-strain elastic modulus and diameters parameters were recovered completely in all three exercise groups.(2)Immediately after exercise,the mean blood flow rate increased by similar amplitude in the three exercise groups.Only the average blood flow rate of AE10 group did not recover after lying for 10 minutes.The blood flow rate was completely restored within 20 minutes after the exercise.(3)Immediately after exercise,the diastolic pressure did not increase in AE10 group,but the variation amplitude of shear stress and oscillating shear index were different from those in CE group.After lying for 10 minutes,blood pressure and oscillating shear index of AE10 group were restored.After resting for 20 min,the blood pressure of AE10 group continued to decrease,while the blood flow resistance parameters of CE group did not completely recover.Conclusions: There was no significant difference in the acute effects of continuous and accumulated exercise on the stiffness and diameter of common carotid arteries,during 30 minutes of moderate intensity cycling and recovery about 20 minutes of resting,and both recovered completely after 10 minutes of resting.The improvement in blood flow to the brain lasted longer in the accumulated exercise pattern than in the continuous exercise pattern.The higher the accumulated frequency,the longer it takes to recover.The more frequency accumulated exercise pattern corresponted to the more permanent regulation of blood pressure and the more rapid decline of oscillating shear index,but the effect of accumulated exercise on blood flow resistance was weaker than that of continuous exercise.In order to improve the cerebral blood supply and regulate blood pressure,it is recommended to choose multiple accumulated exercise.