insomnia , which is difficulty with falling asleep , is more common among aged people . it was 
 found that insomnia occurs in one - third of the general population leading to daytime 
 sleepiness and mental disturbances . it has very serious impacts on individuals health and 
 psychological status which leads to anxiety , depression and poor performance1 . studies have shown that insomnia is also 
 more common among college students and can result in stress , depression and reduced academic 
 performance2,3,4,5,6 . sleep disorders are one of the public health issues that need 
 attention for prevention and early detection , as they are one of the causes of work 
 absenteeism9 . insomnia is defined by the presence of an 
 individual s report of difficulty with sleep10 . subjective assessments includes 
 self- reporting scales like the pittsburgh sleep quality index ( psqi ) , the insomnia severity 
 index ( isi ) , the women s health initiative insomnia rating scale , the basic nordic sleep 
 questionnaire , and the daily sleep log and anxiety index ( stai ) . the insomnia severity index 
 is a valid , reliable and easy to administer tool11 . although pharmacological treatments are effective , they can cause 
 adverse effects such as increased risk of falls , drowsiness , dizziness , cognitive 
 impairment , somnolence , nausea , vomiting and motor vehicle crashes . non pharmacological 
 managements of insomnia include bright light therapy , stimulus control therapy , sleep 
 restriction therapy , sleep hygiene education , cognitive therapy , relaxation therapy , 
 paradoxical intention , and multi- component therapy12 . it has also been found that there is an association between 
 regular exercise or physical activity and the prevalence rate of insomnia13 . most studies have focused on management 
 of clinical insomnia among the middle- aged and elderly , but the aim of our present study 
 was to assess the level of insomnia among female college students , and to determine the 
 association between their physical activity and the insomnia severity index . after obtaining ethical committee approval multiple events were planned at the college of 
 applied medical sciences , king saud university , riyadh , to invite female graduate students 
 to take part in this study . activities like posters , face book events , broadcasts , and 
 lectures were undertaken to motivate the students to participate in the walking program . one 
 hundred and five volunteers as a sample of convenience were included and screened for the 
 inclusion criteria . subjects who had a history of fracture or surgery to the back , pelvis , 
 or lower limb , any contraindications to increased walking , current complaints or conditions 
 affecting their ability to walk , pregnancy or cardiopulmonary disorders were excluded . subjects with insomnia based 
 on the icsd-2 definition , which consists of frequent awakening and difficulty with falling 
 asleep again , difficulty with falling asleep , waking too early , secondary day time 
 impairment due to nighttime sleeplessness were included14 . , 
 medical , socioeconomic and academic details were collected and the isi questionnaire and 
 daily physical log were distributed . in the second stage , a seven- meter distance was taped on the floor to measure stride 
 length , which was calculated by asking subjects to take 10 steps forward , 5 steps with each 
 foot at their natural stride bringing the feet together with the last step . the stride 
 length was calculated by dividing the distance covered by 10 . after recording stride length 
 values , each subject was given a pedometer ( omron model hj-152 ) in the final stage . subjects 
 were instructed to wear the pedometer at the level of the anterior superior iliac spine 
 ( asis ) and also to fill in the daily physical activity log . out of the 105 volunteers , 33 were 
 excluded , and there were 10 dropouts during the 3-week motivation program , leaving finally 
 62 volunteers who successfully completed the study . the insomnia severity index ( isi ) it is comprised of seven questions which are scored 
 on a likert scale ranging from 0 to 4 . the scores range from 0 to 28 : 0 to 7 , no clinically 
 significant insomnia ; 8 to 14 , sub- threshold insomnia ; 15 to 21 , clinical insomnia 
 ( moderate ) ; 22 to 28 , clinical insomnia ( severe ) . the isi is a valid , reliable , and easy to 
 administer questionnaire both as a screening tool and a measurement tool11 . pedometers are small devices that can be 
 worn at the waist or ankle , and are capable of counting the number of steps taken15 . the participants were given an omron 
 ( model hj-152 ) pedometer , and they recorded their total daily steps for three weeks . out of 105 volunteers , 80 subjects met the inclusion criteria , but only 62 could completed 
 the study . prevalence of insomnia : 50% of the subjects 
 had no clinically significant insomnia ( ncsi ) , 42% had sub- threshold insomnia ( sti ) , and 8% 
 had moderate clinical insomnia ( mci ) . physical activity log : the number of steps taken per 
 day was recorded for 3 weeks . this encouraged the subjects to take as many steps as they 
 could to improve their physical activity ( table 
 1table 1 . the results show that physical activity increased from the first to the 
 third week . association between insomnia and sleep problems : pearson correlation analysis 
 revealed a significant correlation between sleep problem and the insomnia severity index 
 after the motivation program ( r= 0.353 , p 0.01 ) ( table 2table 2 . relationship between isi and sleep problemcorrelationssleep probleminsomnia severityindex beforeinsomnia severityindex aftersleep problempearson correlation10.4 ( * * ) 0.3 ( * * ) sig . ( 2-tailed).0.00.0n787265insomnia severityindex beforepearson correlation0.4 ( * * ) 10.7 ( * * ) sig . ( 2-tailed)0.0.0.0n727264insomnia severityindex afterpearson correlation0.3 ( * * ) 0.7 ( * * ) 1sig . association between the number of coffee cups drunk and insomnia : pearson 
 correlation analysis of the insomnia severity index before and after the motivation program 
 with the number of coffee cups drunk per day showed a positive correlation with a value of 
 r=0.178 and ( p=0.149 ) which was not statistically significant . association between physical activity and insomnia : 
 physical activity measured as the number of steps taken correlated with the isi values 
 showing a moderately negative correlation , with values of r= 0.396 at week 1 , and r= 0.378 
 at week 3 ( table 3table 3 . association between physical activity and isincorrelationpair 1pa 1 & isi720.3pair 2pa 3 & isi660.3pa- physical activity in weeks 1 and 3 . this is the first study conducted among saudi female college students to have determined 
 the association between their physical activity and insomnia . the results show that 50% had 
 ncsi ( no clinically significant insomnia ) , 42% had sub- threshold insomnia and 8% had 
 moderate clinical insomnia . the average number of steps taken increased from the first week 
 to the third week . we found a mild negative correlation between physical activity and the 
 insomnia severity index . this is consistent with earlier findings that exercise has a 
 beneficial effect on sleep problems especially insomnia16 . sleep regulates mood and affects learning , memory , concentration 
 and recall , because it is one of the most important processes in a creature s life . on the 
 other hand , poor sleep quality has adverse effects on learning , memory , and awareness 
 adversely affecting work performance , especially among students . students need to show a 
 high level of performance , which may not be achieved with sleep disturbances , because higher 
 mental functions would be affected , leading to unhappiness , irritability , tiredness , 
 depression and decreased level of performance . in 1998 , sherrill et al . associated the level 
 of physical activity and sleep disorders in the middle aged to elderly with obstructive lung 
 airway disease . they reported that women have sleep disturbance and participate in exercise 
 programs more than men , whereas men did regular vigorous activity , and walking at a brisk 
 pace approximately 4.8 to 6.4 km / h . the effect of exercise on sleep is observed when it 
 exceeds 1 hour in duration , and appears to be related to alteration of sleep architecture , 
 e.g. frequency , duration , daytime sleep , quality etc13 . this is consistent with the results of our study that higher 
 physical activity has beneficial effects on sleep quality . researchers conducted a study of 
 patients with end- stage renal disease in saudi arabia . they found that insomnia is common 
 in dialysis patients and was significantly associated with other sleep disorders17 . previous studies also showed that sleep 
 deprivation , and psychological stress are more common among medical students in other 
 countries18,19,20 . moderate intensity aerobic exercise reduced pre - sleep 
 anxiety and improved the sleep of middle - aged and older patients with chronic primary 
 insomnia22 , 23 . previous studies have shown a strong relation between subjective 
 assessment and objective assessment using polysomnography or actigraphy24 , 25 . the insomnia 
 severity index ( isi ) is considered a clinically reliable and valid tool in insomnia 
 treatment research26 . pedometers are 
 considered the most valid and reliable tools for measuring physical activity27,28,29,30 . our present study included a small sample size , and had only a 3-week motivational program 
 for increasing the number of steps taken per day . physical activity was observed to be highest in the 
 second week , and it gradually reduced in the third week . we recommend further research with 
 a longer duration motivation program in a larger group to establish a stronger relationship 
 between physical activity and insomnia .