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Paper text:
the aging process is marked by the diminishing physiological and functional capabilities in 
 older adults .
this decline in function result from the loss of muscular strength and related 
 impaired functional mobility1 , which often 
 leads to falls , low back pain , reduced independence , and increased health - care costs2 .
although the loss of muscle mass with aging 
 ( sarcopenia ) leads to muscular dysfunction3 , obesity also contributes substantially to chronic medical 
 conditions such as low back pain4 .
the 
 notable changes in body composition from maturity to senescence are well proven , even in 
 healthy subjects .
it has been well established that obesity / overweight has side effects on 
 low back pain4 .
so an exercise therapy 
 consisting of individually designed programs , including stretching or strengthening , may 
 improve pain and function in chronic nonspecific low back pain5 .
numerous exercise approaches have been designed with the intention 
 of controlling weight , improving strength , and increasing flexibility for treating low back 
 pain5 .
if these exercises are done in 
 water , the properties of water that cause resistance result in relaxation , reduce the 
 pressure on the affected joint , and induce a feeling of exhilaration . moreover , the 
 combination of the buoyancy and resistance properties allow for exercise modalities in an 
 aquatic environment that are generally too stressful on land for older populations6,7,8 .
although it appears that water - based 
 exercise may be a suitable exercise modality for elderly individuals , little is known about 
 its ability to improve body composition .
the interesting and distinguishing point of 
 differences between previous studies and the presented study is the sort of exercise 
 therapy .
it was hypothesized that water - based exercises would significantly decrease 
 abdominal and overall obesity , increase muscular strength , and consequently decrease low 
 back symptoms in the elderly .
the subjects of the present study were 32 elderly men from qazvin , iran , who met the 
 following selection criteria : over 65  years old , no experience of a fall in the 1  year 
 period prior to the study , no specific disease that might influence task performance , no 
 visual or hearing impairment , and no vestibular organ problem .
all subjects agreed to 
 actively participate in the exercises once they had been given a sufficient explanation of 
 the tasks .
subjects were randomly allocated to two groups : aquatic training , with a mean age 
 of 68.42.9 yr ( 3 d / wk for 12 wk ) , and a control group ( 67.63.1 yr ) .
the aquatic program 
 was conducted in a heated pool ( depth 1.20 m ) at water temperatures between 28  c and 30  c 
 and consisted of 2 aerobic sessions and 1 session of resistance training .
all sessions 
 lasted 60  min and included a warm - up period ( 10 min ) , the main program ( 40 min ) , and a 
 cooldown period ( 10 min ) .
the aerobic regimen included exercises such as water walking , 
 jogging , walking and jogging in combination with various arm movements , sidestepping , water 
 cycling , and adapted water games ( volley and basket ) . during resistance training ,
the 
 following 8 exercises were performed : chest / upper back glide , chest back press , 
 behind - the - back press , pivoted shoulder press ( upper body ) and calf lifts , supported squats , 
 outer / inner thigh scissors , and forward and backward leg glide ( lower body ) .
each movement 
 during resistance training was conducted using specialized equipment to increase the water 
 resistance and the stimulus offered by the water . before planning the exercise therapy in 
 water
, a pulse meter was used to control the heart rates of the subjects ( 5070% of maximal 
 heart rate reserve ) during the time of exercise .
the subjects in the control group did not 
 participate in any kind of exercise program .
body mass index ( bmi ) , percentage of body fat ( pbf ) , 
 waist - hip ratio ( whr ) , and trunk muscle mass were measured with a body composition analyzer 
 ( inbody 230 , biospace , seoul , south korea ) before and after training .
the segmental lean 
 mass such as the trunk muscle mass can be measured with this apparatus . a simple 9-item 
 patient questionnaire ( the keele start back screening tool ) ,
was used to categorize back 
 pain patients in terms of the complexity of their problem .
the tool evaluates not only 
 physical factors , such as pain radiation , severity , and related dysfunction , but also 
 psychosocial factors that can influence outcomes , such as anxiety , depression , and 
 pessimism .
all the subjects gave written informed consent before starting the study 
 protocol , in accordance with the declaration of helsinki .
the independent student s t - tests was used to examine differences 
 between the groups , with a statistical significance level of =0.05 .
after the intervention , bmi , whr , pbf , and trunk muscle mass improved significantly in the 
 aquatic training group ( p<0.05 ) ( table 
 1table 1.body composition variables of participants before and after the 
 interventionaquatic trainingcontrolpre - testpost - testpre - testpost - testbmi ( kg / m)26.60.525.1 0.5 * 26.40.426.30.5whr ( cm)0.950.010.880.01 * 0.910.010.900.01pbf ( % ) 29.80.127.20.2 * 29.70.229.20.1trunk muscle mass ( kg)25.40.726.50.5 * 25.30.625.20.7bmi : body mass index ( calculated as weight in kilograms divided by the square of 
 height in meters ) ; whr : waist / hip ratio ) ; pbf : percent body fat .
* significant 
 difference between the aquatic training ) , and low back pain significantly decreased in the aquatic training group 
 ( p<0.05 ) ( table 2table 2.the effect of water - based exercise on low back painaquatic trainingcontrolpre - testpost - testpre - testpost - testphysical symptoms7376psychological symptoms4133 * significant difference between the aquatic training and control groups at 
 p0.05 ) .
bmi : body mass index ( calculated as weight in kilograms divided by the square of 
 height in meters ) ; whr : waist / hip ratio ) ; pbf : percent body fat .
* significant 
 difference between the aquatic training * significant difference between the aquatic training and control groups at 
 p0.05
the aim of this study was to assess the influence of aquatic exercises on body composition 
 and nonspecific low back pain in elderly males . based on our findings , whr , pbf , bmi , trunk 
 muscle mass , and
low back pain ( both physical and psychological symptoms ) were significantly 
 improved after the intervention . since ; it has been well established that obesity / overweight 
 has side effects on low back pain4 , one 
 reason for low back pain improvement may be related to the change in body composition change 
 in the subjects10 .
consistent with 
 findings from other studies9,10,11 , we found an 
 improvement in low back pain after aquatic exercises .
low abdominal muscular strength is 
 considered to be a reason for low back pain ; thus , increasing the muscular volume and 
 strength may be an effective treatment strategy12 , 
 13 .
our results indicated that the 
 trunk muscle was improved by up to 4.1% after 12 weeks aquatic training .
an advantage of 
 aquatic exercise is that it can involve the upper and lower extremities through optimal 
 ranges of motion while minimizing joint stress .
thus , aquatic exercise can result in optimal 
 improvement in body composition and low back pain .
the present study demonstrated that an 
 improved body composition as a result of aquatic exercise had a positive effect on 
 nonspecific low back pain .
one limitation of this study was the small number of subjects , 
 limiting the extent to which the results can be applied to elderly men in general . 

additional studies involving more subjects , a more controlled environment , and/or a 
 different variety of psychological and physical tests are required in order to make 
 conclusive assumptions about a larger population .
the results obtained suggested that 
 exercises in water may be one of the most useful modes of exercise for elderly individuals 
 with low back pain .
[ purpose ] the purpose of this study was to investigate the effect of aquatic exercises on 
 nonspecific low back pain ( lbp ) in elderly males . 
 [ subjects and methods ] thirty - two 
 elderly men aged 65 or older were recruited and randomly allocated to two groups : aquatic 
 training ( 3 d / wk for 12 wk ) or a control group . 
 body mass index ( bmi ) , percentage of body 
 fat ( pbf ) , waist - hip ratio ( whr ) , and trunk muscle mass were measured before and after 
 training . 
 [ results ] the results suggested that all obesity variables including bmi , whr , 
 and pbf of the aquatic training group were decreased significantly , while the trunk muscle 
 mass of the aquatic training group was increased significantly . 
 furthermore , low back pain 
 was decreased in the subjects after the intervention . 
 [ conclusion ] the water - based program 
 improved lbp and body composition in the elderly men .