stroke is one of the leading causes of death among middle - aged men , along with cancer and 
 cardiovascular disease1 .
stroke is 
 categorized as either cerebral hemorrhage , which arises from the rupture of blood vessels in 
 the brain , or cerebral infarction , which is caused by blocked or narrowed blood vessels2 .
limitations in activities of daily living ( adl ) are found after the occurrence of stroke . 

an extended bedridden state can lead to sarcopenia and reduced muscle strength , muscle 
 endurance , and cardiopulmonary function3 , 4 .
motor disabilities due to stroke - induced 
 hemiplegia and hemiparesis limit physical activity and motor function , and can lead to the 
 accumulation of visceral fat , which is a metabolic risk factor7 . the accumulation of visceral fat results in the excessive release 
 of free fatty acids ( ffa ) and glycerol , which are degradation products of triglycerides 
 ( tg)7 , when ffa and glycerol are 
 excessively introduced into skeletal muscle cells , they interfere with insulin - dependent 
 glucose absorption .
this process leads to the development of hyperglycemia , hyperlipidemia , 
 and insulin resistance . in cases of abdominal obesity resulting from visceral fat accumulation , blood and tissue 
 concentrations of ffa increase simultaneously .
ffa reduces insulin sensitivity in the liver 
 by suppressing insulin - dependent glucose uptake .
this disorder reduces the amount of glucose 
 that available for glycogen synthesis and increases tg build up .
an increase in glucose and 
 ffa levels increases insulin secretion from the pancreas , causing hyperinsulinemia . 

hyperinsulinemia leads to increased sodium re - uptake , sympathetic nervous system ( sns ) 
 activation , hypertension development , and circulating ffa levels8 .
in addition , low concentrations of high - density lipoprotein 
 cholesterol ( hdlc ) are more closely related to the risk of stroke than high tg9 .
low hdlc increases the risk of all 
 arteriosclerotic diseases such as myocardial infarction , stroke , and sudden death . 
 particularly in stroke patients , improvements in hdlc concentration
are considered an 
 important goal in the treatment and reduction of these multiple risks10 . since
metabolic risk factors have various components and interactions , multifaceted 
 prevention and treatment methods are necessary . in particular , stroke patients have a 
 significantly higher chance of metabolic syndrome ( mets ) than to individuals without a 
 stroke history or other specific disease states .
studies have suggested that stroke and mets 
 require multifaceted care , rather than separate treatment of each condition11 .
ffa serves as the link in a vicious cycle 
 of metabolic risk factors ; therefore , it can not be ignored .
it was recently reported that 
 exercise is a non - pharmacologic treatment method that may be effective at preventing brain 
 diseases , enhancing cerebral function , and improving diabetic neuropathy12,13,14 .
recent cohort studies have highlighted the importance of metabolic risk factors , as the 
 improvement of these risk factors in stroke patients reduced total stroke recurrence by 
 1930%11 .
however , in previous studies , 
 the primary goal of exercise programs for stroke patients was the enhancement of functional 
 capacity , as measured by markers such as walking ability , falls , adl , and quality of 
 life15 .
in addition , there were very 
 limited applications of exercises that addressed cardiovascular risk factors or metabolic 
 factor modulations intended for the improvement of metabolic abnormalities .
therefore , the 
 present study aimed to specifically investigate the effects of aerobic exercise as a means 
 of reducing metabolic risk factors of stroke patients .
this study was conducted as a pretest - and - posttest and control group study .
the subjects of 
 the present study were chronic stroke patients diagnosed as having stroke - induced hemiplegia 
 with onset at least 12 months previously .
twenty male patients aged 4759  years without 
 orthopedic conditions that would have affected the study were selected .
subjects were 
 included in the study if they could walk 10 meters within 60 seconds without supplementary 
 assistance16 , were able to understand 
 and follow verbal commands , and agreed to participate in the exercise program . those 
 currently taking drugs were not excluded .
selected subjects were placed into either the 
 exercise group ( n = 10 ) , which performed an aerobic exercise program in addition to 
 receiving rehabilitative therapy , or the control group ( n = 10 ) , which received utilized 
 only the rehabilitation . all subjects completed the pretest before starting the exercise 
 program , as well as the posttest at the conclusion of the 12-week exercise program .
all 
 participants provided their written informed consent to participation in this study prior to 
 their enrollment .
kyungwoon university approved this study , which complies with the ethical 
 standards of the declaration of helsinki .
the physical characteristics of the subjects in 
 each group are shown in table 1table 1 .
physical characteristics of the participants of this experimentvariableage ( years)height ( cm)weight ( kg)bmi ( kg / m)time since stroke(months)stroke type(ischemia / hemorrhage)hemiplegic side(rt / lt)exercise ( n=10)53.73.6167.85.886.25.225.71.547.16.64 / 63 / 7con ( n=10)52.84.1166.45.082.36.224.72.444.87.37 / 32 / 8data are means  sd .. body measurements were made as follows : height ( cm ) and weight ( kg ) were measured and then 
 used to calculate the body mass index ( bmi ) with the equation bmi = weight ( kg)/height 
 squared ( m ) ; and waist and hip circumference were measured with a tape measure 
 to calculate the waist - to - hip ratio ( whr ) .
blood pressure was measured after patient had 
 rested in a sitting position for 5 minutes , using an automatic blood pressure monitor 
 ( ft-500r , jawon medical , seoul , korea ) to obtain the systolic ( sbp ) and diastolic ( dbp ) 
 blood pressure .
blood pressures measurements were obtained twice , and the average values 
 were used in the data analysis ; the time between measurements was 3 minutes .
mean arterial 
 pressure ( map ) was calculated as map = dbp + ( sbp  dbp)/3 .
for the intervention , all subjects received physical therapy consisting of posture , gait 
 and strength training for 30 minutes / day which was conducted by a physical therapist with 
 more than 5  years of bobath technique experience .
the exercise was conducted 
 using a stationary bicycle ( full body exercise active , super dynamic 3 , seoul , korea ) , a 
 rehabilitative exercise machine designed to move the arms and legs together .
the exercise 
 program utilized the heart rate reserve ( hrr ) method to achieve an exercise intensity 
 corresponding to 5070% of the target heart rate ( thr ) .
the program lasted for 30 minutes 
 and was conducted 5 times per week for a total of 12 weeks .
the exercise intensity was 
 initially set at thr 50% , and was increased in 5% increments at 3-week intervals to the 
 maximum of thr 70% . during exercise ,
the heart rate was continuously observed using an 
 automatic pulse monitor by the patient , a professional physical therapist , and an exercise 
 specialist to determine when the thr was achieved . in prior studies ,
although this equation is easy to 
 use due to its simplicity , the rate of change is high .
therefore , hrmax is underestimated in 
 men and women less than 40  years of age , whereas it is overestimated in men and women aged 
 40  years .
the recent american college of sports medicine ( acsm ) guidelines17 recommend the equation of gellish et 
 al.18 as the most accurate equation . 

the present study used this recommended equation to calculate the subjects thrs as follows : 
 thr = ( 206.9  [ 0.67  age ]  hrrest )  % intensity + hrrest .
blood samples were drawn before and after completion of the 12-weekexercise program , under 
 identical conditions and at the same time of day .
serum was separated from the collected 
 blood using a centrifuge . then , the concentrations of tg ( vitros trig dtd , johnson & 
 johnson , new brunswick , nj , usa ) , total cholesterol ( tc ; vitros chol dtd , johnson & 
 johnson ) , and glucose ( vitros glu dtd , johnson & johnson ) were analyzed with a vitros 
 chemistry dt60 ii ( johnson & johnson ) using slides .
hdlc was analyzed using magnesium 
 chloride and dextran sulfate to precipitate apo b - containing cholesterol ; hdlc ( vitros hdlc 
 dtd , johnson & johnson ) slides were used for vitros chemistry dt60 ii analysis ( johnson 
 & johnson ) . ffa ( nefa hr kit , wako , osaka , japan ) was analyzed using a hitachi 7180 
 ( hitachi , tokyo , japan ) .
two - way repeated measure analysis of variance ( anova ) was conducted for all data variables 
 in order to express the average and standard deviation values , and to test the group trends 
 before and after the exercise program .
comparisons of changes in the average values of 
 measurement variables before and after the 12-week exercise program were analyzed using the 
 paired samples t - test .
in addition , the variation (  ) between baseline measurements and 
 measurements after 12 weeks of exercise was calculated , and pearson s correlation 
 coefficient was used to test for correlations between the measurement variables (  score = 
 change in score between pre - test and posttest ) .
all statistical analyses were conducted with 
 the statistical package for the social sciences ( spss)-pc ( version 18.0 ; ibm corporation , 
 endicott , ny , usa ) , and statistical significance was accepted for values of p0.05 .
table 2table 2 . changes in obesity indices and blood pressure with 12-week exercise 
 trainingmeasured variablegrouppretestposttestscoreweight ( kg)exercise86.25.283.33.02.93.2con82.36.283.06.60.71.8bmi ( kg / m)exercise25.71.524.80.80.80.9con24.71.424.91.40.20.5wc ( cm)exercise94.07.688.58.15.42.8***con92.36.792.46.80.10.8whrexercise0.940.030.890.040.050.05**con0.960.040.960.060.010.03sbp ( mmhg)exercise133.712.8127.95.45.89.3con131.315.6132.117.50.87.2dbp ( mmhg)exercise87.110.482.44.54.68.8con85.711.286.111.80.45.1map ( mmhg)exercise102.610.697.64.25.08.4con100.912.4101.413.40.55.3data are meanssd , score = change in the score * p value of paired t - test ( * : 
 p<0.05 , * * : p<0.01 , * * * : p<0.001 ) ,   p value of two - way anova test 
 ( grouptime , : p<0.05 , : p<0.01 , : 
 p<0.001 ) , bmi : body mass index , wc : waist circumference , whr : waist to hip ratio , 
 sbp : systolic blood pressure , dbp : diastolic blood pressure , map : mean arterial 
 pressure shows the comparative results of the changes in obesity indices and blood 
 pressure of stroke patients after the 12-week exercise program .
the obesity markers of 
 weight ( p < 0.01 ) , bmi ( p < 0.01 ) , wc ( p < 0.01 ) , and whr ( p < 0.01 ) showed a 
 significant interaction effect . however , no significant effect was observed for blood 
 pressure .
data are meanssd , score = change in the score * p value of paired t - test ( * : 
 p<0.05 , * * : p<0.01 , * * * : p<0.001 ) ,   p value of two - way anova test 
 ( grouptime , : p<0.05 , : p<0.01 , : 
 p<0.001 ) , bmi : body mass index , wc : waist circumference , whr : waist to hip ratio , 
 sbp : systolic blood pressure , dbp : diastolic blood pressure , map : mean arterial 
 pressure table 3table 3 .
changes in serum lipids and free fatty acid ( ffa ) levels elicited by exercise 
 trainingmeasured variablegrouppretestposttestscoretg ( mg / dl)exercise172.666.8134.548.938.153.7*con173.458.9161.551.511.951.8tc ( mg / dl)exercise208.255.7168.827.439.446.2*con205.534.1207.636.92.021.4hdlc ( mg / dl)exercise41.011.253.08.212.010.3***con39.88.543.48.43.62.7glucose ( mg / dl)exercise101.713.894.24.37.514.3con102.513.4103.810.61.39.8ffa ( eq / l)exercise431.4139.2324.373.2107.1146.4*con449.3109.0411.180.438.287.2data are meanssd , score = change in the score between pretest and posttest , * p 
 value of paired t - test ( * : p<0.05 , * * : p<0.01 , * * * : p<0.001 ) ,   p 
 value of two - way anova test ( grouptime , : p<0.05 , : 
 p<0.01 , : p<0.001 ) , tg : triglycerides , tc : total cholesterol , 
 hdlc : high density lipoprotein cholesterol , ffa : free fatty acid . shows the results of the changes in blood lipids and ffa in stroke patients 
 after 12 weeks of exercise training .
there was a significant difference in tg according to 
 measurement time ( p = 0.04 ) , and an interaction effect was observed with tc ( p < 0.01 ) . 

hdlc , an important marker of improvement in metabolic risk factors , showed a significant 
 interaction effect ( p = 0.02 ) with exercise training .
additionally , there was a significant 
 difference in ffa levels according to the measurement time ( p < 0.01 ) .
data are meanssd , score = change in the score between pretest and posttest , * p 
 value of paired t - test ( * : p<0.05 , * * : p<0.01 , * * * : p<0.001 ) ,   p 
 value of two - way anova test ( grouptime , : p<0.05 , : 
 p<0.01 , : p<0.001 ) , tg : triglycerides , tc : total cholesterol , 
 hdlc : high density lipoprotein cholesterol , ffa : free fatty acid . table 4table 4 .
correlation between the measured factors and the degree of changes elicited by 
 12-weeks of exercise trainingmeasured variableweightbmiwctgtchdlcglucoseffaweight10.999**0.2820.5050.4470.762 * 0.2970.667*bmi0.999**10.2860.5110.4280.762 * 0.2890.657*wc0.2820.28610.0660.2200.3110.640*0.064tg0.5050.5110.06610.5010.4570.6010.726*tc0.4470.4280.2200.50110.5750.2740.669*hdlc0.762*0.762 * 0.3110.4570.57510.1940.776**glucose0.2970.2890.640 * 0.6010.2740.19410.550ffa0.667 * 0.657*0.0640.726 * 0.669*0.776**0.5501 * correlation is significant at the 0.05 level ( 2-tailed ) , * * correlation is 
 significant at the 0.01 level ( 2-tailed ) shows the correlation between changes (  score ) in the measurement variables 
 of the 12-week exercise program .
ffa levels , a direct cause of metabolic risk factors , 
 showed significant positive correlations with weight ( r = 0.66 , p < 0.05 ) , bmi ( r = 0.65 , 
 p < 0.05 ) , tg ( r = 0.72 , p < 0.05 ) , and tc ( r = 0.66 , p < 0.05 ) , and a significant 
 negative correlation with hdlc ( r = 0.77 , p < 0.01 ) .
conversely , the metabolic 
 improvement factor hdlc showed significant negative correlations with the obesity indices of 
 weight ( r = 0.76 , p < 0.05 ) and bmi ( r = 0.76 , p < 0.05 ) , as well as a significant 
 negative correlation with ffa ( r = 0.77 , p < 0.01 ) . * correlation is significant at the 0.05 level ( 2-tailed ) , * * correlation is 
 significant at the 0.01 level ( 2-tailed )
weight , bmi , wc , and whr are reported to be predictive factors of stroke . weight and stroke 
 risk are positively correlated19 , and it 
 has been proposed that wc and whr are risk factors of obesity - related stroke occurrence2 , 20 . 
 the results of the present study show that the each of variables of weight , bmi , wc , and whr 
 demonstrated an interaction effect with the measurement time and group , indicating that 
 regular exercise was effective at improving obesity indices .
this finding is likely a result 
 of implementing appropriate amounts of exercise through a program that considered individual 
 patients ` abilities .
however , no significant changes were observed in blood pressure ( sbp , 
 dbp , and map ) in the present study . although even small reductions in sbp and dbp have been 
 shown to significantly decrease stroke risk21 , the difficulty in identifying the effect of exercise in the 
 present study may be attributable to the fact that most of the study participants were using 
 blood pressure - related medications .
stroke - induced reductions in physical activity and abdominal fat accumulation reduce the 
 action of lipoprotein lipase ( lpl ) , suppressing the breakdown of tg and increasing blood ffa 
 concentrations22 . during the process in 
 which cholesterol ester transferase converts cholesterol and tg from hdlc to 
 very - low - density lipoprotein cholesterol ( vldlc ) , the high tg content results in a reduction 
 in hdlc concentration23 .
the results of 
 the present study show there was a decrease in tg and ffa levels at the end of the 12-week 
 intervention , and tc and hdlc showed an interaction effect .
these results are consistent 
 with those of carl et al.24 we consider 
 that regular exercise suppressed vldlc synthesis , reducing tg concentrations and relatively 
 increasing hdlc levels .
in addition , exercised - induced increases in lpl activity in the 
 muscle and adipose tissues are considered show improvement in lipid metabolism , due to the 
 suppression of tc and tg synthesis in the liver , as well as decreased liver uptake of 
 ffa25 , 26 . in the initial phase of exercise ,
the muscles use glycogen stored 
 within the muscle as an energy source . compared to lipid utilization
, however , this glycogen 
 supply only provides energy for a short period of exercise27 .
thus , the main energy source of the muscles in the context of 
 continuous exercise is fatty acids , which are oxidized within the mitochondria to provide 
 the energy needed for the muscles28 .
an 
 increase in fatty acid oxidation may therefore effectively improve metabolic risk factors by 
 reducing circulating levels of blood ffa .
consequently , improvements in lipid metabolism 
 observed after regular exercise in the present study are likely related to ffa oxidation and 
 suppression of tg synthesis . in addition
, low concentrations of hdlc have been reported to 
 be closely related to stroke risk9 , and 
 the significant exercise - induced increase in hdlc observed in the present study suggests 
 that exercise may be an effective means of reducing the risk of stroke recurrence . in 
 particular , the observed significant negative correlation between ffa and hdlc ( r = 0.77 , p 
 < 0.01 ) indicates the need for systematic and regular exercise programs for stroke 
 patients .
the various types of metabolic factors examined in the present study are intricately 
 connected in a metabolic cascade . unlike specific pharmacologic agents , exercise
individualizing the 
 exercise intensity to patient fitness and characteristics is the most important factor in 
 achieving this effect .
since stroke patients have concomitant limitations in physical 
 activity and motor disabilities , andmay also have several metabolic comorbidities such as 
 hypertension , diabetes , cardiovascular disease , and obesity , the intensity of the prescribed 
 aerobic exercise must be determined through accurate testing .
furthermore , detraining can 
 occur because of personal disposition or various other factors , resulting in rapid changes 
 in adapted physical responses .
therefore , further research is necessary to develop exercise 
 programs that patients can enjoy over the long term .
   [ purpose ] the present study investigated the effects of regular exercise on the 
 improvement of free fatty acid ( ffa ) levels and metabolic risk factors of stroke patients . 
 
 [ methods ] the subjects were 20 male patients aged 4759  years who were diagnosed as having 
 hemiplegia resulting from stroke . 
 exercise was conducted using a stationary bicycle , a 
 rehabilitative exercise machine . 
 the exercise program utilized the heart rate reserve 
 ( hrr ) method to create an exercise intensity amounting to 5070% of the target heart rate 
 ( thr ) . 
 the program lasted for 30 minutes and was conducted 5 times per week for a total of 
 12 weeks . 
 [ results ] in stroke patients , 12 weeks of exercise training yielded a 
 significant interaction effect with weight , body mass index ( bmi ) , waist circumference 
 ( wc ) , and waist - to - hip ratio ( whr ) . 
 there were also significant differences in 
 triglycerides ( tg ) according to the time of measurement , and an interaction effect was 
 observed for triglycerides ( tc ) . 
 high - density lipoprotein cholesterol ( hdlc ) , an important 
 marker of improvement in metabolic risk factors , showed a significant interaction effect 
 with exercise training . 
 in addition , free fatty acids ( ffa ) showed a significant 
 difference based on the time of measurement and showed a significant negative correlation 
 with hdlc ( r = 0.77 ) . 
 [ conclusion ] the results of the present study suggest that regular 
 exercise by stroke patients reduces their risk of metabolic complications and stroke 
 recurrence by reducing obesity indices , improving serum lipid and ffa levels , and 
 increasing hdlc levels . 
INTRODUCTION
SUBJECTS AND METHODS
RESULTS
DISCUSSION