according to the brazilian institute of geography and demography ( instituto brasileiro de geografia e estatstica or ibge),1 brazil presents an aged population that corresponds to 9.7% of its total population .
the aging index grew from 0.11 in the 1980 s to 0.25 in 2004.1 these values show that brazilian society is aging , but it can still be considered young when compared to other countries , such as italy , japan and germany , which present larger elderly populations.1 the aging process has been widely studied in the last decade , enhancing the understanding of diseases that affect elderly people and , therefore , promoting a shift towards a healthier and more independent aging process . amongst the physiological modifications observed during aging ,
the loss of functional capabilities and the modifications of metabolic functions are the most important.2,3 studies show that regular physical activity is a key feature for more healthful aging.3,4 the risk of disease and health problems can decrease with exercise,3,4 which may also help the immune system recover in the elderly , reducing the prevalence of infections and neoplasias among exercisers.3 regular exercise can also decrease fat mass and increase lean mass and aerobic performance.5 in general , physical exercise has proven to be beneficial for diseases associated with aging , and these benefits may result from any type of physical activity
. however , resistance exercises , as the most effective method for developing muscle strength , have shown specific benefits and are currently prescribed by many major health organizations to improve health and fitness.3 when sedentary for a long time , elderly people can present significant alterations in body composition and physical fitness , compromising their quality of life in many important ways .
some chronic diseases , for instance aids , can even worsen this situation because such diseases exacerbate the effects of aging on body composition and muscle strength .
recovering strength and physical fitness is the major goal of exercise in patients with aids wasting syndrome .
therefore , a resistance training program could form the basis of an exercise prescription for this group of patients .
it should be progressive , so resistance increases as the patient becomes stronger.6 some studies involving hiv - positive adults and resistance training have been carried out , but no studies focusing on elderly hiv - positive people have been conducted yet.79 the present study aims to describe a case series of hiv - positive elderly people who participated in a progressive resistance training program and to evaluate their body composition , muscular strength , physical fitness and evolution of cd4 and cd8 cell counts .
this is a case series study10 describing the effects of a one - year resistance training program among elderly hiv - positive patients .
all hiv - positive patients , 60 or more years old and who were being treated for hiv / aids at the hospital das clnicas da faculdade de medicina da universidade de so paulo by the end of 2003 were invited to participate in this study .
the first invitation was made either by telephone or directly at the medical consultation , followed by written correspondence to their homes . after obtaining their written agreement to participate in the research , orientation to the program
the institutional research ethical committee approved the study after review , and all participants signed a formal written , informed consent form .
inclusion criteria were the following : hiv - positive , older than 60 years by july 2003 , lack of regular physical activity practice and agreement to participate .
exclusion criteria were the following : medical contraindication to perform exercises , any physical condition that limited resistance of training , use of corticosteroids or other anabolic steroids and non - adhesion to the training program ( defined as an absence of at least three consecutive months from the training program ) .
after the initial interview , patients were questioned about the time since their hiv diagnosis , in addition to their health and life conditions .
patients were clinically followed by their own infectious disease - specialized physicians throughout the study . both immunological evaluations , by means of t - cd4 and t - cd8 lymphocytes counts , and virological evaluations , by means of quantitative hiv - rna pcr , were standard practice and performed every four months for those who attended the clinic .
the anthropometric measurements collected in this study were body mass , circumferences and skinfolds , assessed according to protocols previously described.11,12 body composition assessments by dual - energy x - ray absorptiometry ( dexa ) were carried out before and after the training period , following the methods described by ellis.13 the supervised progressive resistance training program consisted of four different exercises ( muscles trained ) : 1 ) leg press ( quadriceps ) , 2 ) seated row ( latissimus dorsi ) , 3 ) lumbar extension ( paravertebral muscles ) , and 4 ) chest press ( pectoralis major ) .
exercises were performed using free weight machines ( maxiflex biodelta , joinville , sc , brazil ) .
exercises were performed in three sets of 812 repetitions at light , moderate and heavy resistance , respectively , with 12 minutes of rest between the series , twice a week for one year , from march 2004 to september 2005 . according to our protocol , adapted from the american geriatric society recommendations,14 all subjects
were submitted to five training sections , prior to the beginning of the training program , in order to assure an adequate and safe evaluation of their initial working load.15 sub - maximum weight supported ( in the heavy resistance series ) was defined as the maximum weight lifted smoothly without valsalva maneuver , apnea or isometry . for the purposes of this work , it was a surrogate of muscular strength .
patients were also submitted to two functional tests every four months in order to better evaluate their physical performance evolution along the training period .
the tests included an assessment of a timed 2.4-meter walk ( walking 2.4 m ) at a normal pace and a timed test of five repetitions of rising from a chair and sitting down ( sit - standing ) , according to the protocol described by guralnik et al.16 data were recorded and stored in an excel sheet and analyzed with statistica for windows , version 7.5 .
the differences seen in strength , anthropometric variables and functional tests before and after the one - year training period were compared with wilcoxon matched pair test , considering the entire sample and controlling for age and gender effects as well as for baseline hiv infection stage and co - morbidity presented by them .
one hundred and eight hiv - positive patients , more than 60 years old by the end of 2003 , were invited to participate in the study . of those , two refused , two died , and two did not have the physical condition necessary to participate in the training program .
in addition , 88 patients did not show interest or were unable to participate in the study because they lived outside so paulo city and/or presented poor clinical conditions .
thus , only 14 patients , aged 6271 years ( mean  sd : 65.6  2.9 ) , of both genders and with average of nine years duration of hiv infection , agreed to participate .
in addition , three of these patients abandoned the training program for more than three months and were excluded from the study protocol .
therefore , only 11 completed the period of training and remained in the study for the final analysis . among those 11 participants ,
only one did not report previous use of highly active antiretroviral therapy ( haart ) , and four presented previous histories of hiv - associated diseases . on average
table 2 shows the weight load variation after one year of resistance training program with four different exercises .
the average load of each muscular group trained increased significantly : leg press 97% , p = 0.004 ; seated row 78% , p = 0.021 ; lumbar extension 122% , p = 0.003 ; and chest press 74% , p = 0.003 . the increased muscular strength is reflected in the results of the two functional tests performed .
there was a significant reduction in both the sit - standing ( 2.00  1.57s , p=0.003 ) and the walking 2.4 m ( 9.25  6.58s , p=0.003 ) times when comparing before and after the year of resistance training , as shown in figures 1 and 2 .
weight did not change significantly , nor did most of the body composition measures analyzed ( see table 3 ) , with the exception of triceps and thigh skinfolds , which both showed significant reduction ( 11.4  9.2 mm , p = 0.037 ; and 13.9  12.1 mm , p = 0.011 , respectively ) , as shown in figure 3 .
the differences seen in all variables described above were not affected by age , gender , hiv infection stage or co - morbidity with the exception of strength variation in seated row , which increased more among men ( p=0.02 ) .
in addition , no significant adverse effect related to the exercise program or any new ( or worsening of previously existent ) aids - related condition developed during the training period . finally , with respect to the evolution of virological and immunological markers of hiv infection , all but two patients ( patients aap and afs of table 1 ) had persistently undetectable viral loads . also , there were significant increases in the cd4 cell counts ( 388  163 before vs.  539  225 after ,  = 151 cells , p=0.008 ) and in the cd4/cd8 ratio ( 0.63 to 0.81 , p=0.009 ) and a non - significant increase in the cd8 cell counts ( 762  423 before vs.  816  376 after ,  = 54 cells ; p=0.464 ) .
to the best of our knowledge , this is the first study to investigate the influence of progressive resistance training in hiv - infected people older than 60 years .
the training protocol followed the recommendations of american college of sports and medicine3 , which suggest a progression model for resistance exercises in healthy , older adults . for this population ,
the studies show favorable changes regarding the risk factors associated with osteoporosis , heart disease , cancer and diabetes and also show a reduction in fat mass and an increase in lean mass and muscular strength.4,18 as mentioned in the results , only 11 out of 14 hiv - infected people , aged 60 years or more , completed the one - year training period . among them , those who experienced some intercurrence during the training period did not suffer deconditioning . when they restarted training , it was easy for them to continue with the same loads they used before .
a substantial strength increase was seen for all exercises in every patient who completed the training program regardless of their age , gender , baseline hiv infection stage or the presence of any hiv / aids - associated morbidity , and this was not different for the only patient who did not use antiretrovirals .
the average increase in the load supported after 12 months of resistance training varied from 74 to 122% ( p0.0030.021 ) , depending on the muscular group considered .
in addition , the functional tests results , which showed significant improvement in the sit - standing and walking 2.4 m times ( p= 0.003 ) , reflected this increase . before starting the training program , the patients were all sedentary and , in spite of having different baseline hiv infection stages and co - morbidity histories , they had stable clinical conditions .
thus , the strength increase observed could hardly be attributed to any other cause but the training program .
the strength increment is important for the quality of life of the aged population because it improves biomechanics and cardiovascular responses , thus facilitating daily life activities .
our sample was comprised of elderly hiv - positive individuals who were experiencing a stable clinical evolution , almost all of them under haart treatment for more than one year prior to the beginning of the study .
however , despite the significant benefits associated with haart , hiv infection and its therapy have been associated with the development of several metabolic complications : increased central adiposity , peripheral lipoatrophy , peripheral insulin resistance , diabetes , dyslipidemia and hypertriglyceridemia , osteoporosis and osteopenia .
these complications may predispose patients to a premature risk of metabolic and cardiovascular diseases.19 in addition , aging predisposes them to the same biological effects,20 and one could expect that aging could act as a potentiator of those hiv infection- and haart - related alterations . on the other hand , resistance training improves many of those alterations in our study , no changes were seen either in body composition , assessed by dexa after 12 months of resistance training , or in anthropometric measures with the exceptions of triceps ( p=0.037 ) and thigh ( p=0.011 ) skinfolds . weight did not change significantly ( p=0.84 ) either .
we are well aware that this could be simply an effect of the lack of power of the study due to the small size .
however , the low intensity of the alterations seen in table 3 and the fact that some of them are opposite to what is the expected effect of resistance training could suggest that the absence of statistical significance may be true .
finally , the effects of exercises on immune function have been studied in both adult and elderly healthy populations , showing that moderate levels of training are helpful for both populations.21,22 in our study , assessment of immune response , which is usually performed for hiv patients , showed a significant increase in both cd4 counts ( =151 cells , p=0.008 ) and in the cd4/cd8 ratio ( 0.63 to 0.81 , p=0.009 ) in addition to a non - significant increase in the cd8 counts (  = 54 cells ; p=0.464 ) after one year of resistance training .
those are important variations in the number of cells , considering that there were no significant changes in viral load or haart use among them during the training period .
almost all patients had undetectable viral load and were on haart therapy before , during and after the training period .
therefore , the observed changes in the numbers of cd4 and cd8 cells , together with the absence of new hiv - related morbidity , should most probably be attributed to their stable hiv infection conditions . in conclusion , despite the relatively small sample , our results indicate that a progressive resistance training program can benefit elderly people living with hiv without any major adverse effects or worsening of hiv / aids related conditions , which favors its recommendation for such a population .
 backgroundelderly people present alterations in body composition and physical fitness , compromising their quality of life . 
 chronic diseases , including hiv / aids , worsen this situation . 
 resistance exercises are prescribed to improve fitness and promote healthier and independent aging . 
 recovery of strength and physical fitness is the goal of exercise in aids wasting syndrome.objectivethis study describes a case series of hiv - positive elderly patients who participated in a progressive resistance training program and evaluates their body composition , muscular strength , physical fitness and the evolution of cd4 + and cd8 + cell counts.methodssubjects were prospectively recruited for nine months . 
 the training program consisted of three sets of 812 repetitions of leg press , seated row , lumbar extension and chest press , performed with free weight machines hts , twice / week for one year . 
 infectious disease physicians followed patients and reported all relevant clinical data . 
 body composition was assessed by anthropometric measures and dual - energy x - ray absorptiometry before and after the training program.resultsfourteen patients , aged 6271 years old , of both genders , without regular physical activity who had an average of nine years of hiv / aids history were enrolled . 
 the strengths of major muscle groups increased ( 74%122% , p=0.0030.021 ) with a corresponding improvement in sit - standing and walking 2.4 m tests ( p=0.003 ) . there were no changes in clinical conditions and body composition measures , but triceps and thigh skinfolds were significantly reduced ( p=0.037 ) . 
 in addition , there were significant increases in the cd4 + counts ( n=151 cells ; p=0.008 ) and the cd4+/cd8 + ratio ( 0.63 to 0.81 , p=0.009).conclusionresistance training increased strength , improved physical fitness , reduced upper and lower limb skinfolds , and were associated with an improvement in the cd4 + and cd4+/cd8 + counts in hiv positive elderly patients without significant side effects . 
INTRODUCTION
METHODS
RESULTS
DISCUSSION