negative change within the carotid artery is reportedly an independent risk factor for 
 cardiovascular disease ( cvd ) and stroke1 . 

several studies report an association of cvd risk with increased of carotid intima - media 
 thickness ( cimt)2,3,4 and luminal diameter 
 ( cld)5 , 6 .
recently , a followed - up study reported that low carotid artery flow 
 velocity ( i.e. peak - systolic velocity [ psv ] and end - diastolic velocity [ edv ] ) is associated 
 with cvd risk in hypertensive patients7 . 

another study focusing on risk factor evolution and cvd development demonstrated that low 
 psv and edv were independently associated with future cvd8 . a cross - sectional study comparing patients with ischemic stroke 
 patients and subjects without stroke found an association between lower carotid flow 
 velocity ( fv ) and increased stroke risk9 . 

several cross - sectional studies reported that improved of oxygen uptake and walking speed is 
 associated with preventing to the negative change of carotid arteries ( in cimt or cld ) in 
 elderly3 , 10 .
resistance exercise is effectively improves of physical performance such as muscle 
 strength , agility and dynamic balance , flexibility , walking ability , and aerobic endurance 
 in the elderly11,12,13 .
additionally , resistance 
 exercise can improve body composition , including decreasing body fat mass or increasing of 
 lean body mass in elderly populations11 , 12 .
in contrast , studies on the effect of 
 resistance exercise on arterial function demonstrated that resistance exercise improves 
 vascular endothelial function and increases blood flow velocity in the brachial artery in 
 healthy overweight women and young adults14 , 15 .
also , resistance exercise is reported to 
 decrease the cimt and increase the cld in the carotid artery in patients with chronic heart 
 failure patients16 . however , the effects 
 of resistance exercise on carotid artery fv parameters are not yet known in healthy elderly 
 men
. therefore , we examined the effect of a 24 weeks resistance exercise program on carotid 
 artery flow velocity in this population .
in this study initially enrolled 42 healthy elderly men ( age 65  years ) without 
 hypertension , hyperlipidemia , diabetes , history of cvd , or other diagnosed illness .
twelve 
 subjects were excluded for smoking ( n=7 ) , and regular participation in physical activity 
 within the past 6 months ( n=5 ) .
the remaining 30 elderly men were randomly divided into a 
 control group ( n=15 ) and a resistance exercise group ( n=15 ) .
table 1table 1.the anthropometric characteristics , body composition and blood pressure of 
 subjectsvariablescontrol group(n=15)exercise group(n=15)age ( years)70.9  3.973.1  3.0height ( cm)164.9  7.5164.8  5.4body mass  ( kg)64.5  8.066.0  6.1body mass index  ( kg / m)23.8  2.924.3  2.1percent body fat mass ( % ) 23.7  7.125.6  6.2skeletal muscle mass  ( kg)27.3  3.027.4  3.7systolic blood pressure ( mmhg)127.7  6.7129.1  7.4diastolic blood pressure ( mmhg)74.4  8.075.1  8.2values are means  sd shows the participants physical characteristics . in accordance with the 
 ethical standards of the declaration of helsinki , informed consent was obtained from all 
 participants after they were provided with a detailed description of the study .
values are means  sd after measuring the subjects height and body mass , their body fat mass ( fm ) percent and 
 skeletal muscle mass ( sm ) were measured by bioelectrical impedance analysis , using a body 
 composition analyzer ( inbody 370 , biospace , seoul , south korea ) .
body mass index ( bmi ) was 
 calculated as weight ( kg ) divided by height squared ( m ) .
for the 2 days prior to 
 measurement of body composition , subjects were asked to not engage in physical activities 
 other than the activities they usually performed and to refrain from drinking or eating 
 excessively .
systolic blood pressure ( sbp ) and diastolic blood pressure ( dbp ) were measured 
 using a mercury sphygmomanometer ( hico , tokyo , japan ) after 10 minutes of rest .
upper and lower body muscle strength , agility / dynamic balance , flexibility , walking 
 ability , and aerobic endurance were measured after a 10-minute warm up .
muscle strength was 
 measured by grip strength using a grip strength dynamometer ( tkk-5401 , japan ) for the upper 
 body and chair stand up for the lower body .
chair stand up were scored based on the number 
 of repetitions completed within 30 seconds . agility and dynamic balance
was measured by the 
 time up and go ( tug , 2.44 m ) .
participants were informed that this was a timed test and that 
 the objective was to walk as quickly as possible ( without running ) around a cone and back to 
 the chair .
participants were instructed 
 to take a deep breath and then breathe out while leaning forward as far as possible , without 
 bending the knees .
in addition , participants started walking two meters before the start line so that 
 walking speed did not include the acceleration time . and maximum walking speed was defined 
 as the ratio between distance and time .
two - minute steps was measured as an alternative to 
 the aerobic endurance test .
participants score was the number of full steps completed in 2 
 minutes , raising each knee to a point midway between the patella and iliac crest .
resistance exercises used in this study conformed to the guidelines of physical activity 
 recommended for the elderly17 .
the 
 resistance exercise was performed with green elastic exercises bands ( thera - band , ohio , usa ) 
 for 3050 minutes per session , 3 days per week , with 1015 repetitions per set ( weeks 112 : 
 1012 repetitions per set ; weeks 1324 : 1315 repetitions per set ) , 35 sets ( weeks 112 : 3 
 sets , weeks 1324 : 5 sets , 1 minute rest between sets ) for 14 items ( elbow flexion , lateral 
 raise , shoulder flexion and extension , biceps curl , chest press and flies , abdominal crunch , 
 trunk extension , side bend , mini squat , leg press , calf raise , and ankle inversion)17 , 18 .
participants performed a 10-minute warm and cool down before and 
 after the exercise program , respectively .
carotid artery variables were measured using b - mode ultrasound and a 10  mhz probe ( logiq 3 , 
 ge healthcare , wauwatosa , wi , usa ) .
cimt 
 and systolic cdl were measured from the far wall of the distal common carotid 1  cm proximal 
 to the carotid bifurcation .
the cimt was defined as the distance from the lumen - intima 
 interface to the intima - adventitia interface , and systolic cld was defined as the distance 
 between the near and far wall intima - media interfaces19 . for doppler spectral analysis ,
peak systolic flow velocity ( psv ) 
 and end diastolic flow velocity ( edv ) were measured by continuous - wave doppler examination 
 in the common carotid 13  cm proximal to the bifurcation8 .
wall shear rate ( wsr ) was calculated using to the following 
 formula20:wsrpeak=4vpeak / cldwhere 
 wsr is wall shear rate ( s ) , vpeak is the peak systolic flow velocity and cld is 
 systolic luminal diameter . statistical package for the social sciences ( spss ) ver . 17.0
chicago , il , usa ) 
 was used for statistical analysis , and results reported as mean and standard deviation .
the 
 student s t - test was used to assess differences in baseline variables .
two - way factorial 
 analysis of variance was used to compare parameters at baseline and after the 24 weeks of 
 the study participation .
when significant group  time interactions were identified , paired 
 t - tests were performed to detect differences between time points .
table 2table 2.changed of body composition , blood pressure , physical function , and carotid 
 artery variables in baseline and after 24 weeksvariablescontrol group ( n=15)changeexercise group ( n=15)changebaseline24 weekbaseline24 weekbody fat mass percent ( % ) 23.7  7.123.8  6.60.125.6  4.325.0  3.61.2*skeletal muscle mass ( kg)27.3  3.027.0  3.00.327.4  3.728.2  3.70.8**systolic blood pressure
( mmhg)127.7  6.7127.9  6.30.2129.1  7.4128.3  6.10.8*diastolic blood pressure ( mmhg)74.4  8.074.5  6.90.175.1  8.274.9  7.40.4left grip strength ( kg)33.3  5.532.9  5.40.431.0  6.633.0  5.52.04**right grip strength ( kg)33.2  5.232.9  5.00.331.2 
7.134.3  5.83.1**chair stand up ( repetitions/30 sec)16.3  3.616.1  3.00.216.3  3.418.2  3.11.9**sit and reach ( cm)10.0  6.19.9  6.00.18.9  7.89.8  7.50.9**maximum walking speed ( m / sec)1.67  0.31.64  0.30.031.58
 0.21.67  0.30.09**time up and go ( sec)5.84  1.05.86  1.00.025.87  1.15.65  0.80.22*two - minute step test ( repetitions)101.4  13.1101.3  12.10.199.3  15.6103.1  12.93.9**carotid intima media thickness ( mm)0.71  0.110.71  0.100.00.71  0.080.71  0.070.0systolic carotid luminal diameter ( cm)0.62  0.10.62  0.10.00.63  0.10.64  0.10.01peak systolic flow velocity ( cm / sec)63.4  9.962.6  11.10.862.2  13.971.4  13.09.2**end diastolic flow velocity ( cm / sec)20.4  3.820.5  3.80.119.2  3.721.0  4.01.8**wall shear rate ( s)409.6  65.3403.7  74.65.9403.1  108.1453.9  116.750.8*values are means  sd .
significantly different within group : * p<0.05 , * * p<0.01 ; 
 significant group  time interaction : p<0.05 , p<0.01 , p<0.001 shows changes of body composition , blood pressure , physical function , and 
 carotid variables in baseline and after 24 weeks .
fm percent ( p<0.05 ) , sm ( p<0.01 ) , 
 and sbp ( p<0.05 ) showed significant interactions .
grip strength on the left ( p<0.01 ) 
 and right ( p<0.001 ) , chair stand up ( p<0.01 ) , sit and reach ( p<0.05 ) , maximal 
 walking speed ( p<0.01 ) , tug ( p<0.01 ) , and two - minute step ( p<0.01 ) had significant 
 interactions .
psv ( p<0.001 ) , edv ( p<0.05 ) , and wsr ( p<0.05 ) showed significant 
 interactions .
however , in the dbp , cimt , and cld , interactions were no identified .
values are means  sd . significantly different within group : * p<0.05 , * * p<0.01 ; 
 significant group  time interaction : p<0.05 , p<0.01 , p<0.001 in the paired t - test results of the exercise group , fm percent , sbp , and tug were 
 significantly decreased ( p<0.05 , each ) , and sm , left and right grip strength , chair stand 
 up , sit and reach , maximal walking speed , and two - minutes step were significantly increased 
 ( p<0.01 , each ) , also psv ( p<0.01 ) , edv ( p<0.01 ) , and wsr ( p<0.05 ) were 
 significantly increased after 24 weeks .
body composition , blood pressure , and physical 
 function variables showed no change in the control group .
but in exercise group , dbp , cimt , 
 and cld were no change , also in control group , all variables were no change .
this study examined the effects of a 24-week resistance exercise program on carotid 
 parameters in elderly men .
the primary findings of this study are that the resistance 
 exercise program increased pfv , edv , and wsr in this study population .
decreased of carotid artery fv is associated with early progress of atherosclerosis , and 
 stoke in elderly patients9 .
in addition , 
 two recently cross - sectional studies reported that low psv and edv were independently 
 associated with future dvd7 , 8 .
the previous studies suggest that increase of psv and edv 
 is associated with a potential prevention for cvd .
studies on the effects of exercise training on arterial parameters demonstrated that 
 resistance exercise increases blood flow in the femoral artery and increases flow mediated 
 dilation of the brachial artery in adults14 , 21 , 22 .
resistance exercise is also reported to increase the flow velocity 
 of the brachial and femoral artery in adults and older subjects15 , 22 .
changes in 
 brachial and femoral parameters due to resistance exercise are considered to significantly 
 improve of peripheral artery function14 , 15 .
however , effects of long - term resistance 
 exercise on carotid artery fv have not been confirmed .
several studies reported that carotid 
 fv is increased during dynamic exercise or after acute high intensity exercise in young 
 adults23 , 24 .
a study of obese adults reported that resistance exercise alone 
 could improve brachial artery endothelial function14 . in the present study ,
this study demonstrated that long - term resistance exercise improves to 
 age - related carotid fv in health elderly men .
aging is reported as a major risk factor for 
 decreased of carotid artery flow25 . in 
 the elderly , improvement of carotid fv by exercise
low wsr is associated with increased cimt , and is directly associated with changes in 
 carotid fv , viscosity , and cld26 . in the 
 current study ,
wsr was used as a surrogate marker of wall shear stress , and was calculated 
 by systolic cld and psv26 .
we found that 
 exercise resulted in increased psv , but there was no change in cld .
two intervention studies in overweight 
 or obese adults demonstrated that short- or long - term resistance training is not effective 
 in improving cimt and cld14 , 21 . in this study ,
this result suggests that resistance exercise does not effectively 
 improve cimt and cld in health elderly .
two intervention studies demonstrated that resistance exercise using weightlifting machine 
 is effectively improves of body composition and physical function in the elderly11 , 12 .
other intervention study demonstrated that resistance exercise using 
 elastic band is effectively improves physical fitness such as muscle function and balance 
 ability in elderly women13 . and 

resistance exercise using elastic band are simple and economical , and have safety 
 advantages13 . in this study ,
resistance 
 exercise was to use elastic bands , and health - related indicators such as blood pressure as 
 well as body composition and physical fitness variables were examined .
this study showed 
 that resistance exercise using elastic bands for 24 weeks is effectively improves of blood 
 pressure as well as body composition and physical fitness variables in elderly .
therefore , effects of resistance exercise on the carotid artery may be limited to elderly 
 men . in conclusion , 24-week resistance exercise program ,
using elastic bands , effectively 
 improves carotid flow velocity and wall shear rate in healthy elderly men .
 [ purpose ] the aim of this study was to examine the effect of resistance exercise on 
 carotid intima - media thickness , luminal diameter , peak systolic flow velocity , end 
 diastolic flow velocity , and wall shear rate in healthy elderly men . 
 [ subjects and 
 methods ] thirty healthy elderly men ( age 65  years ) were randomly divided into a control 
 ( n=15 ) and resistance exercise ( n=15 ) groups . 
 the 24-week exercise intervention consisted 
 of 3 days of resistance exercise per week using an elastic band per week . 
 body 
 composition , physical function , blood pressure , and carotid variables were measured at 
 baseline and after 24 weeks . [ results ] body fat percent , skeletal muscle mass , systolic 
 blood pressure , grip strength , arm curl , chair stand up , sit and reach , maximum walking 
 speed , time up and go , and two - minute step test showed significant interaction . 
 peak 
 systolic flow velocity , end diastolic flow velocity , and wall shear rate also showed 
 significant interaction . [ conclusion ] a 24-week resistance exercise program , using elastic 
 bands , effectively improves carotid flow velocity and wall shear rate in healthy elderly 
 men . 
INTRODUCTION
SUBJECTS AND METHODS
RESULTS
DISCUSSION