Effects of 8-week swimming training on carotid arterial stiffness and hemodynamics in young overweight adults.
BACKGROUND
Exercise has been found to either reduce or increase arterial stiffness. Land-based exercise modalities have been documented as effective physical therapies to decrease arterial stiffness. However, these land-based exercise modalities may not be suitable for overweight individuals, in terms of risks of joint injury. The purpose of this study was to determine the effects of 8-week swimming training and 4-week detraining on carotid arterial stiffness and hemodynamics in young overweight adults.


METHODS
Twenty young male adults who were overweight were recruited and engaged in 8-week of swimming training and 4-week detraining. Five individuals withdrew due to lack of interest and failure to follow the training protocol. Body Fat Percentage (BFP) and carotid hemodynamic variables were measured on a resting day at the following intervals: baseline, 4 weeks, 8 weeks after swimming training and 4 weeks after detraining. A repeated analysis of variance (ANOVA) was used to assess the differences between baseline and each measurement. When significant differences were detected, Tukey's test for post hoc comparisons was used.


RESULTS
Eight-week swimming training at moderate intensity decreased BFP, including the trunk and four extremities. Additionally, the BFP of the right and left lower extremities continued to decrease in these overweight adults 4 weeks after ceasing training. Carotid arterial stiffness decreased, while there were no significant changes in arterial diameters. Blood flow velocity, flow rate, maximal and mean wall shear stress increased, while systolic blood pressure and peripheral resistance decreased. No significant differences existed in minimal wall shear stress and oscillatory shear stress.


CONCLUSIONS
Eight-week swimming training at moderate intensity exhibited beneficial effects on systolic blood pressure, arterial stiffness and blood supply to the brain in overweight adults. Moreover, maximal and mean wall shear stress increased after training. It is worth noting that these changes in hemodynamics did not last 4 weeks. Therefore, further studies are still warranted to clarify the underlying relationship between improvements in arterial stiffness and alterations in wall shear stress.
Department of Physical Education, Dalian University of Technology, Linggong Road, Dalian, China.
Wen-Xue
WX
Yuan
Department of Physical Education, Dalian University of Technology, Linggong Road, Dalian, China.|Department of Biomedical Engineering, Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Linggong Road, Dalian, China.
Hai-Bin
HB
Liu
Department of Physical Education, Dalian University of Technology, Linggong Road, Dalian, China.
Feng-Shan
FS
Gao
Department of Engineering Mechanics, Dalian University of Technology, Linggong Road, Dalian, China.
Yan-Xia
YX
Wang
Department of Biomedical Engineering, Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Linggong Road, Dalian, China. krqin@dlut.edu.cn.
Kai-Rong
KR
Qin
D000704:Analysis of Variance; D001783:Blood Flow Velocity; D001794:Blood Pressure / Q000502:physiology; D002339:Carotid Arteries / Q000503:physiopathology*; D015444:Exercise / Q000502:physiology; D006439:Hemodynamics; D006801:Humans; D007596:Joints / Q000503:physiopathology; D008297:Male; D050177:Overweight / Q000150:complications / Q000503:physiopathology*; D013550:Swimming / Q000502:physiology*; D013997:Time Factors; D014655:Vascular Resistance / Q000502:physiology; D059289:Vascular Stiffness / Q000502:physiology*; D055815:Young Adult
Arterial stiffness; Hemodynamics; Overweight adults; Swimming training