saying goes-"charity begins at home  , we should first promote the health of our own students who are going to be the future doctors . until and unless our students themselves practice health promotional measures , they are very less likely to guide and motivate their patients and the community to do so . as an ancient holistic system of wellness , yoga is a scientifically validated , time tested and socially acceptable health promotional technique developed thousands of years ago in our own country.(910111213 ) so far very few studies have been done on effect of yoga on health status of medical students , therefore department of community medicine has done this innovative experiment by introducing yoga in the first block posting of m.b.b.s . 3 semester students to find out the impact as well as the feasibilityof short term yoga intervention on mental health status of medical students . participants included 90 students of mbbs 3 semester who came for their 1 posting in the department of community medicine in different batches . participants included 40 males and 50 females within the age group of 18 - 23 years . september 2009-november 2010 . cross sectional pre and post interventional study . before initiating yoga practices the students were shown the published research work done on yoga and health in the leading indian and western medical institutions . timing of yoga practice was kept from 9 - 10 am daily and it was ensured that yoga practice did not affect the regular teaching program . the students were given 45 minutes for yoga practice every day in the beginning of posting for one month . yoga class consisted of following practices : 
 preliminary preparation - 5 min.asana ( postures ) 
 suryanamskar - 5 minutestadasanatriaktadasanakatichakrasana 10 minuteshalasanapascimottanasanashavasana 
 pranayama ( breathing exercise ) 
 anulome - vilomekapalbhati 15 minutesbharamri 
 meditation with sound 10 minutes 
  preliminary preparation - 5 min . suryanamskar - 5 minutestadasanatriaktadasanakatichakrasana 10 minuteshalasanapascimottanasanashavasana 
  suryanamskar - 5 minutes katichakrasana 10 minutes pranayama ( breathing exercise ) 
 anulome - vilomekapalbhati 15 minutesbharamri 
  kapalbhati 15 minutes meditation with sound 10 minutes these classes were conducted by a trained yoga physician ( m.sc yoga ) available full time in the college on regular basis . in order to assess the impact on general and mental well being , the 28-item general health questionnaire ( ghq-28)(14 ) was applied at baseline i.e. , in the beginning of intervention and at the end of study i.e. , after completion of intervention on all the participated students . each consisting of seven items as follows : 
 somatic symptoms ( item 1 - 7).anxiety / insomnia ( item 8 - 14).social dysfunction ( item 15 - 21).depression ( item 22 - 28 ) . anxiety / insomnia ( item 8 - 14 ) . social dysfunction ( item 15 - 21 ) . participants rated their symptoms over the past few weeks on a four point likert scale . the likert scoring method is continuous and scores of ( 0 , 1 , 2 , 3 ) were assigned to each item and summed up giving a score ranging from 0 - 84 . anonymous feedback was also taken at the end of intervention to understand students experience of yoga . data was collected , tabulated and statistical analysis was done using microsoft excel 2007 software and paired t - test was applied to compare the means of before and after intervention . participants included 90 students of mbbs 3 semester who came for their 1 posting in the department of community medicine in different batches . participants included 40 males and 50 females within the age group of 18 - 23 years . before initiating yoga practices the students were shown the published research work done on yoga and health in the leading indian and western medical institutions . timing of yoga practice was kept from 9 - 10 am daily and it was ensured that yoga practice did not affect the regular teaching program . the students were given 45 minutes for yoga practice every day in the beginning of posting for one month . yoga class consisted of following practices : 
 preliminary preparation - 5 min.asana ( postures ) 
 suryanamskar - 5 minutestadasanatriaktadasanakatichakrasana 10 minuteshalasanapascimottanasanashavasana 
 pranayama ( breathing exercise ) 
 anulome - vilomekapalbhati 15 minutesbharamri 
 meditation with sound 10 minutes 
  preliminary preparation - 5 min . suryanamskar - 5 minutestadasanatriaktadasanakatichakrasana 10 minuteshalasanapascimottanasanashavasana 
  suryanamskar - 5 minutes katichakrasana 10 minutes pranayama ( breathing exercise ) 
 anulome - vilomekapalbhati 15 minutesbharamri 
  kapalbhati 15 minutes meditation with sound 10 minutes these classes were conducted by a trained yoga physician ( m.sc yoga ) available full time in the college on regular basis . in order to assess the impact on general and mental well being , the 28-item general health questionnaire ( ghq-28)(14 ) was applied at baseline i.e. , in the beginning of intervention and at the end of study i.e. , after completion of intervention on all the participated students . each consisting of seven items as follows : 
 somatic symptoms ( item 1 - 7).anxiety / insomnia ( item 8 - 14).social dysfunction ( item 15 - 21).depression ( item 22 - 28 ) . anxiety / insomnia ( item 8 - 14 ) . social dysfunction ( item 15 - 21 ) . participants rated their symptoms over the past few weeks on a four point likert scale . the likert scoring method is continuous and scores of ( 0 , 1 , 2 , 3 ) were assigned to each item and summed up giving a score ranging from 0 - 84 . anonymous feedback was also taken at the end of intervention to understand students experience of yoga . data was collected , tabulated and statistical analysis was done using microsoft excel 2007 software and paired t - test was applied to compare the means of before and after intervention . out of the 90 students posted in the community medicine , eightstudents were not regular . they were absent either at the time of pre or post test , therefore excluded from the study and final analysis included only 82 students . on comparison of mean total scores of before and after intervention comparison of mean total scores before and after intervention on comparing the mean scores according to four subscales of ghq-28 , there was a significant decrease in the mean of each subscale before and after specific yoga intervention [ table 2 ] . comparison of mean subscale mental scores before and after intervention students scoring on each question before and after intervention is given in tables 3 - 6 for all the four subscales i.e. , somatic symptoms , anxiety / insomnia , social dysfunction , depression respectively . distribution of students answers in relation to somatic symptoms distribution of students answers in relation to anxiety / insomnia distribution of students answers in relation to social dysfunction distribution of students answers in relation to depression apart from the improvement observed in mental well being score , the students also reported other beneficial effects of yoga in their anonymous feedback such as : 
 better sleep30%better concentration in studies-40%.better control of anger and other negative symptoms-25%.more relaxed and active throughout the day-80%.getting positive energy at the beginning of the day-60% . better control of anger and other negative symptoms-25% . more relaxed and active throughout the day-80% . our study has found significant improvement in the mental well being in all the four tested areas ( somatic symptoms , anxiety , social dysfunction , depression ) of medical students following short term yoga intervention . our results are consistent with other studies on yoga among medical students - a study done by simard , henry(15 ) showed improvement in overall health , perceived stress and depressive symptoms following the 16 week yoga intervention among 14 . 1 year medical students assessed by ghq-12 , perceived stress scale and centre for epidemiology depression scale . another study by malathi , damodaran(16 ) also showed a statistically significant reduction in anxiety among 50 first year medical students following yoga practices assessed by spillberger 's anxiety scale . so far the studies assessing the impact of yoga on medical student 's health and particularly mental health have been few in india and rare in this part of country . the unique feature of this study is that it is not a time bound funded project . it is a continuous ongoing program included in the community medicine schedule for the block posting of mbbs students ( 3 semester ) . for this intervention no separate time or space has to be requested from any other department . there it is likely to be continued batch after batch since it has been very well accepted by the students as well as college authorities . if there is such a significant improvement in mental health after doing yoga for only one month then we can imagine what can be the impact if yoga practice is continued for longer time or included in the daily routine by the medical students . since the aim of both community medicine and yoga is health promotion and disease prevention , there is strong reason to include yoga in teaching of community medicine . yoga is an easy , safe , low cost , acceptable and scientifically validated preventive and promotive approach for health therefore it should be included it in the teaching curriculum of community medicine in mbbs course so that our future doctors adopt and maintain positive health and disseminate the same to their patients and the community .