lifestyle and health - related behaviors are strongly associated with morbidity and mortality in many chronic diseases worldwide .
major factors include diet , physical activity , smoking , body mass index ( bmi ) , and alcohol consumption [ 35 ] .
for example , university students experience significant changes in their diet due to busy class schedules and extracurricular activities , as well as the abundance of opportunities for eating out and drinking alcohol . in addition , excessive interest in appearance and poor health literacy even lead some to develop a habit of skipping meals . moreover , according to previous research , although most university campuses provide physical environments that promote physical activities , more than 54.8% of university students do not participate in sufficient physical activity and 25.8% do not participate in any physical activity at all .
these unhealthy behaviors have been reported to cause diseases such as obesity , cancer , cardiovascular disease , cerebrovascular disease , and osteoporosis . in south korea ,
the incidence of osteoporosis in young women and the prevalence of obese young adults have increased sharply over the last decade .
young adulthood is a transitional period that bridges adolescence and adulthood , and the lifestyle of a person during this period not only reflects their past lifestyle , but may also predict their future lifestyle in adulthood and beyond .
failure to recognize the unhealthy lifestyles of young adults may therefore limit the success of childhood health promotion programs .
first line interventions for health promotion in young adults tend to target diet and physical activity [ 1416 ]
. however , only a few studies have investigated the effects of programs promoting healthy eating habits that also include physical activity . moreover ,
most relevant studies on the effects of a diet or physical activity program were long - term studies lasting more than 8 weeks .
however , in a preliminary study on the need for a health promotion program targeting young adults , we found that most respondents expected to experience a remarkable change after participating in a short - term intensive experience program .
short - term programs have been shown to improve skeletal muscle strength , insulin sensitivity and serum lipids , as well as aid weight loss and changes in body composition .
for example , a previous study reported that a 14-day diet and exercise intervention decreased body mass index ( bmi ) , insulin sensitivity , triglycerides ( tg ) and total cholesterol ( tc ) in 21 overweight or obese children .
similarly , a 6-day yoga and diet change program conducted in 47 obese adults reduced bmi , waist and hip circumference , fat - free mass and hand - grip strength .
therefore , this study was conducted to assess the impact of an intensive 10-day health promotion program combining healthy diet and physical activity on body composition , physical fitness , and biochemical parameters of young adults .
as college - based researchers often find it easier to recruit on campus , university students were chosen as participants of this health promotion study for young adults .
the selection criteria were ( 1 ) no physical and/or psychological disease before study commencement and ( 2 ) no history of participation in any health promotion programs .
each group required 17 subjects to detect an effect size of 0.80 with a power of 0.70 at a 0.05 level of significance .
this number was based on a previous study , which suggested 10% of the project sample size ( 10 to 30 participants ) to be appropriate for the pilot study . despite male students being eligible for inclusion , they were reluctant to participate in the program
. therefore , 34 female undergraduate students enrolled in the study , and were randomly assigned to the intervention group or the control group ( 17 in each group ) .
subjects family names were arranged according to the korean alphabet , and then research randomization 4.0 , a randomized computer program , was used to perform the randomization .
however , 3 students dropped out before the baseline examination because of scheduling conflicts and one dropped out before the follow - up examination because of a health condition ( figure 1 ) .
finally , 30 participants ( 16 in the intervention group and 14 in the control group ) were included in this study .
this study was approved by the ethical committee of sahmyook university and complied with the ethical standards of the declaration of helsinki .
the intensive 10-day health promotion program combining diet and physical activity ( 10-rhpdp ) was designed and conducted by experts , professors , and researchers of nutrition , exercise , and lifestyle .
all participants followed a planned 24-hour schedule during the program . after getting up at 6:00 a.m. and having breakfast
, participants listened to health - related lectures on nutrition , exercise , and health for 3 hours in the morning and 1 hour after lunch for a total of 24 hours over the 10-day period . to ensure the long - lasting effects of the program , healthy diet , exercise , massage practice ,
in addition , participants exercised for a total of 23 hours over the 10-day period , which included taking a light walk for 1 hour every morning , and undertaking aerobic , flexibility , and strength exercises for 2 hours in the afternoon . before lunch , participants engaged in healthy cooking sessions for a total of 8 hours over the 10-day period . after dinner , participants listened to a lecture on massage theory and practiced for a total of 16 hours over the course of the program .
all participants had to drink water frequently throughout the day ( a daily total of 1.5 l of water ) and go to bed after the 10:00 p.m. roll call ( no later than 10:30 p.m. ) . with regard to the exercise program , participants ran 45 km a day at the track for aerobic exercise .
they were instructed , encouraged , and supervised to run for 1 km at a low speed at which conversation was possible , for 23 km at a speed at which conversation was slightly uncomfortable , and for the last 1 km at the individual s maximum speed .
after finishing the aerobic exercise , all the participants moved to an indoor gym and performed 10 different flexibility exercises and 6 different core exercises , maintaining each pose for 30 seconds and resting for 15 seconds between poses . in total , 3 sets of these exercises were performed over approximately 40 minutes .
food was consumed at a scheduled time and place , and a vegetarian diet planned by a nutritionist was available for consumption in unlimited amounts .
the diet comprised a variety of fruits and vegetables , whole grains , dairy products , eggs and legumes .
participants assigned to the intervention group lived and engaged in activities as a group according to a 24-hour schedule . dietary intake and physical activity outside the predetermined schedule were impossible because of strict supervision by the experiment assistants .
participants assigned to the control group spent 10 days consuming their normal diets and refraining from any formal exercise , as per their usual custom .
all subjects attended a baseline assessment at sahmyook university prior to study commencement . a 12-hour fasting blood sample ( approximately 10 ml )
weight ( kg ) , bmi , body fat ( percent ) , and muscle mass ( kg ) were measured with a bioelectrical impedance analysis instrument ( biospace co. , seoul , south korea ) after resting for approximately 20 minutes . to assess physical fitness , muscle strength ( grip and leg and back extension ) , flexibility ( sit and reach , shoulder ) , balance ( single - leg standing ) , and cardiorespiratory capacity ( 12-minute run ) were measured using a grip dynamometer ( ds total sports , incheon , south korea ) , dynamometer ( takei scientific instruments co. , tokyo , japan ) , and sit and reach box ( ds total sports , incheon , south korea ) .
serum levels of tg , tc , high - density lipoprotein cholesterol ( hdl - c ) , low - density lipoprotein cholesterol ( ldl - c ) were measured using the enzymatic colorimetric assay method ( model ; p , roche co , mannheim , germany ) .
glucose levels were measured with enzymatic kinetic assays ( hexokinase ) ( model ; p , roche co , mannheim , germany ) .
insulin levels were measured with electrochemiluminescence immunoassays ( eclia ) ( model ; e , roche co , mannheim , germany ) .
homeostasis model assessment of insulin resistance index ( homa - ir ) , the index value of the indicator representing the insulin resistance , was calculated using the following formula : homa - ir=[fasting plasma insulin ( iu / ml )  fasting plasma glucose ( mmol / l ) ] .
statistical analysis was performed using the ibm spss program for windows version 20.0 ( ibm corp .
, armonk , ny , usa ) . all data are expressed as mean  standard deviation . the mann 
whitney u test for intergroup comparisons and wilcoxon signed - rank test for intragroup comparisons were used .
as college - based researchers often find it easier to recruit on campus , university students were chosen as participants of this health promotion study for young adults .
the selection criteria were ( 1 ) no physical and/or psychological disease before study commencement and ( 2 ) no history of participation in any health promotion programs .
each group required 17 subjects to detect an effect size of 0.80 with a power of 0.70 at a 0.05 level of significance .
this number was based on a previous study , which suggested 10% of the project sample size ( 10 to 30 participants ) to be appropriate for the pilot study . despite male students being eligible for inclusion , they were reluctant to participate in the program
. therefore , 34 female undergraduate students enrolled in the study , and were randomly assigned to the intervention group or the control group ( 17 in each group ) .
subjects family names were arranged according to the korean alphabet , and then research randomization 4.0 , a randomized computer program , was used to perform the randomization .
however , 3 students dropped out before the baseline examination because of scheduling conflicts and one dropped out before the follow - up examination because of a health condition ( figure 1 ) .
finally , 30 participants ( 16 in the intervention group and 14 in the control group ) were included in this study .
this study was approved by the ethical committee of sahmyook university and complied with the ethical standards of the declaration of helsinki .
the intensive 10-day health promotion program combining diet and physical activity ( 10-rhpdp ) was designed and conducted by experts , professors , and researchers of nutrition , exercise , and lifestyle .
all participants followed a planned 24-hour schedule during the program . after getting up at 6:00 a.m. and having breakfast
, participants listened to health - related lectures on nutrition , exercise , and health for 3 hours in the morning and 1 hour after lunch for a total of 24 hours over the 10-day period . to ensure the long - lasting effects of the program , healthy diet , exercise , massage practice ,
in addition , participants exercised for a total of 23 hours over the 10-day period , which included taking a light walk for 1 hour every morning , and undertaking aerobic , flexibility , and strength exercises for 2 hours in the afternoon . before lunch , participants engaged in healthy cooking sessions for a total of 8 hours over the 10-day period . after dinner , participants listened to a lecture on massage theory and practiced for a total of 16 hours over the course of the program .
all participants had to drink water frequently throughout the day ( a daily total of 1.5 l of water ) and go to bed after the 10:00 p.m. roll call ( no later than 10:30 p.m. ) . with regard to the exercise program , participants ran 45 km a day at the track for aerobic exercise .
they were instructed , encouraged , and supervised to run for 1 km at a low speed at which conversation was possible , for 23 km at a speed at which conversation was slightly uncomfortable , and for the last 1 km at the individual s maximum speed .
after finishing the aerobic exercise , all the participants moved to an indoor gym and performed 10 different flexibility exercises and 6 different core exercises , maintaining each pose for 30 seconds and resting for 15 seconds between poses . in total , 3 sets of these exercises were performed over approximately 40 minutes .
food was consumed at a scheduled time and place , and a vegetarian diet planned by a nutritionist was available for consumption in unlimited amounts .
the diet comprised a variety of fruits and vegetables , whole grains , dairy products , eggs and legumes .
participants assigned to the intervention group lived and engaged in activities as a group according to a 24-hour schedule .
dietary intake and physical activity outside the predetermined schedule were impossible because of strict supervision by the experiment assistants .
participants assigned to the control group spent 10 days consuming their normal diets and refraining from any formal exercise , as per their usual custom .
all subjects attended a baseline assessment at sahmyook university prior to study commencement . a 12-hour fasting blood sample ( approximately 10 ml )
weight ( kg ) , bmi , body fat ( percent ) , and muscle mass ( kg ) were measured with a bioelectrical impedance analysis instrument ( biospace co. , seoul , south korea ) after resting for approximately 20 minutes . to assess physical fitness , muscle strength ( grip and leg and back extension ) , flexibility ( sit and reach , shoulder ) , balance ( single - leg standing ) , and cardiorespiratory capacity ( 12-minute run )
were measured using a grip dynamometer ( ds total sports , incheon , south korea ) , dynamometer ( takei scientific instruments co. , tokyo , japan ) , and sit and reach box ( ds total sports , incheon , south korea ) .
serum levels of tg , tc , high - density lipoprotein cholesterol ( hdl - c ) , low - density lipoprotein cholesterol ( ldl - c ) were measured using the enzymatic colorimetric assay method ( model ; p , roche co , mannheim , germany ) .
glucose levels were measured with enzymatic kinetic assays ( hexokinase ) ( model ; p , roche co , mannheim , germany ) .
insulin levels were measured with electrochemiluminescence immunoassays ( eclia ) ( model ; e , roche co , mannheim , germany ) .
homeostasis model assessment of insulin resistance index ( homa - ir ) , the index value of the indicator representing the insulin resistance , was calculated using the following formula : homa - ir=[fasting plasma insulin ( iu / ml )  fasting plasma glucose ( mmol / l ) ] .
statistical analysis was performed using the ibm spss program for windows version 20.0 ( ibm corp . ,
whitney u test for intergroup comparisons and wilcoxon signed - rank test for intragroup comparisons were used .
the mean age of the subjects was 20.01.1 years , the mean height was 161.75.1 cm , and the mean weight was 56.28.7 kg . before the intervention , there were no statistically significant differences in any variables between the intervention and control groups , thus ensuring homogeneity between the groups ( table 2 ) .
body weight and bmi decreased significantly in the intervention group compared with that in the control group ( p<0.001 ) .
there were no statistically significant differences in fat - free mass , muscle mass , skeletal muscle mass , fat mass , or body fat percentage between the 2 groups ( table 3 ) . back and leg strength , bilateral grip strength , waist flexibility , bilateral shoulder flexibility , balance , and cardiorespiratory endurance increased significantly in the intervention group compared to that in the control group ( p<0.01 to p<0.001 ) ( table 4 ) .
tg , tc , ldl - c , glucose levels and homa - ir decreased significantly in the intervention group compared to those in the control group ( p<0.05 to p<0.001 ) , but there were no statistically significant differences for hdl - c and insulin .
the mean age of the subjects was 20.01.1 years , the mean height was 161.75.1 cm , and the mean weight was 56.28.7 kg . before the intervention , there were no statistically significant differences in any variables between the intervention and control groups , thus ensuring homogeneity between the groups ( table 2 ) .
body weight and bmi decreased significantly in the intervention group compared with that in the control group ( p<0.001 ) .
there were no statistically significant differences in fat - free mass , muscle mass , skeletal muscle mass , fat mass , or body fat percentage between the 2 groups ( table 3 ) .
back and leg strength , bilateral grip strength , waist flexibility , bilateral shoulder flexibility , balance , and cardiorespiratory endurance increased significantly in the intervention group compared to that in the control group ( p<0.01 to p<0.001 ) ( table 4 ) .
tg , tc , ldl - c , glucose levels and homa - ir decreased significantly in the intervention group compared to those in the control group ( p<0.05 to p<0.001 ) , but there were no statistically significant differences for hdl - c and insulin .
this study was performed to determine the effects of the 10-rhpdp on body composition , physical fitness , and blood factors of young adults .
the program was effective in reducing weight and bmi , and in increasing back muscle strength , leg muscle strength , grip strength , waist and shoulder flexibility , balance , and cardiorespiratory endurance of young adult females aged 1822 years .
few studies worldwide have investigated the effects of a short - term intensive health promotion program that combines diet and physical activity in healthy young adults .
therefore , direct comparison of study results is difficult . a study performed in adults aged 1850 years , however , reported a decrease in body weight and total fat mass after the implementation of a program combining a hypocaloric diet and exercise training . in a study of women aged 1950 years
, a program combining a 15002000 calories / day diet , 3060 minutes / day of moderate - intensity physical activity , and behavioral modification consultations was found to reduce bmi and body fat percentage . in another study
investigating the effects of diet and exercise , alone or combined , on weight and body composition in obese menopausal women , there was a statistically significant weight loss in the low - fat diet and moderate - intensity aerobic exercise groups , but the greatest change was observed in the group where a combination of both interventions was applied . a randomized controlled trial conducted by christensen et al .  
designed a workplace intervention to achieve an energy deficit of 1200 kcal / day including strengthening exercise ( 15 minutes / hour ) , aerobic fitness ( 2 hours / week ) , and cognitive behavioral training ( 1 hour / week ) .
this resulted in a reduction in weight , bmi , and body fat percentage , and increased back muscle strength and hand grip strength .
similarly , rigamonti et al .   reported that a 3-week multidisciplinary body weight reduction program combining an energy - restricted diet , 90 min / daily aerobic physical activity , psychological counseling , and nutritional education , improved bmi and percent fat mass in 7 obese male adolescents .
these results provide important evidence on the benefit of a health promotion program for healthy young adults , as well as the feasibility of adhering to the program for at least 10 days for overweight or obese young adults . as with the previous studies ,
the findings of this study suggest that undergoing a short - term lifestyle program can enhance the physique and physical fitness of healthy adults .
therefore , to achieve successful health promotion , it is important to help participants recognize the importance of a healthy lifestyle by providing training on healthy eating habits and adequate physical activity .
it is believed that encouraging young adults to participate in a health program , albeit a short - term one , is important .
although the control group in this study had spent 10 days maintaining their normal lifestyle , there was a decrease in leg strength after 10 days .
this could be because the participants may have been unmotivated to perform the leg strength measurements .
in addition , the korean culture views demonstrations of physical strength as unfeminine , which may have contributed to the subjects reluctance to engage in the assessment .
another important finding was the discovery that the 10-rhpdp was effective in reducing serum lipid and glucose levels as well as insulin resistance in our subjects .
the program also increased hdl - c and reduced insulin levels , although these findings were not statistically significant .
a study investigating the effects of diet and physical activity in young adults aged 1835 years showed similar results 
jakicic et al .   reported that a 6-month diet and physical activity program decreased participants tc , tg , and glucose levels and increased their fitness levels .
although other studies demonstrated biochemical parameters levels comparable to those found in our study , they varied widely with respect to duration , size , population , and types of diet and exercise interventions used .
besnier et al .   demonstrated a reduction in insulin levels and homa - ir after individualized exercise training combined with a fruit- and vegetable - rich diet in overweight or obese women , and otten et al .   reported improved glycemic control and homa - ir after a paleolithic diet with 1 hour of supervised exercise ( aerobic exercise and resistance training ) 3 times per week among 32 patients with type 2 diabetes .
similarly , brekke et al .   showed that tc , ldl - c , and insulin levels were decreased and hdl - c levels increased after a 12-week behavior modification intervention with diet and exercise among overweight and obese lactating women .
.   found that tg , tc , and ldl - c levels were reduced but hdl - c levels were not significantly changed by diet and aerobic exercise intervention in 6 studies , which may help explain the improvements seen in this study .
thus , the 10-rhpdp may be efficacious in improving the glycemic control and blood lipid levels of young adults . finally , combining diet and physical activity interventions can reduce the risk of developing multiple lifestyle diseases such as obesity , diabetes , hypertension , and cardiovascular diseases in young adults .
there were no statistically significant changes , however , in fat - free mass , muscle mass , skeletal muscle mass , fat mass , or body fat percentage
. this may be because ( 1 ) most of the results of the variables fell within the normal ranges , ( 2 ) it is difficult to produce a change during a 10-day period , or ( 3 ) the subjects had vegetarian diets that did not provide sufficient protein .
this study was the first randomized pilot trial of a short - term lifestyle modification program in healthy south korean young adults .
the aim of the study was to improve several health - related parameters by combining diet and physical activity interventions .
experts , professors , and researchers of nutrition , exercise , and lifestyle designed and facilitated the program .
additionally , compared with previous trials that took place over a longer period and took a less intensive approach ( including biweekly or triweekly meetings ) , this study used an intensive program over a short period of time , which is likely the reason for the high compliance among our study participants however , the study had several limitations .
second , all of the participants were females , as it was difficult to recruit male participants for the diet intervention .
therefore , the possibility that the effect of the 10-rhpdp may differ according to sex can not be excluded .
third , the study only targeted the students of a single university ; therefore , generalization of the results should be done carefully . in the future
, further research should be conducted with a larger sample size . despite the study s limitations
, its findings suggest that the 10-rhpdp can improve not only the physique and physical fitness , but also the glycemic control and blood lipid levels of young adults .
the results of this study showed that an intensive 10-day health promotion program improved weight , bmi , muscle strength , muscle flexibility , balance , cardiorespiratory endurance , homa - ir , and tg , tc , ldl - c , and glucose levels in a group of young women .
it is easy to administer and may be an effective way to improve body composition , physical fitness , glycemic control , and blood lipid levels in this population .
 backgrounda lifestyle characterized by poor eating habits and physical inactivity is a risk factor for multiple lifestyle diseases in young adults . 
 this study assessed the effects of implementing an intensive 10-day health promotion program combining diet and physical activities on body composition , physical fitness , and biochemical parameters of young adults.material/methodsin this randomized pilot study , 30 female undergraduate students were randomly allocated to an intervention and a control group . the health promotion program consisted of unlimited amounts of vegetarian food ; aerobic , flexibility , and strength exercises ( 3 hours / day ) ; lectures on health ( 3 hours / day ) ; massage practice ( 2 hours / day ) ; and healthy cooking practice ( 1 hour / day ) . 
 the effects of the intervention were analyzed using the mann - whitney u test and the wilcoxon signed - rank test.resultsthe intensive 10-day health promotion program significantly reduced body weight , body mass index , triglyceride , total cholesterol , low - density lipoprotein cholesterol , blood glucose , and the homeostasis model assessment of insulin resistance . at the same time , participants demonstrated increased back muscle , leg muscle , and grip strength ; waist and shoulder flexibility ; balance ; and cardiorespiratory endurance.conclusionsthe intensive 10-day health promotion program is a viable intervention for improving body composition , physical fitness , glycemic control , and blood lipid levels in young adults . 
Background
Material and Methods
Participants
The intensive 10-day health promotion program
Data collection and outcome measurement
Statistical analysis
Results
Demographic and clinical characteristics at baseline
Body composition
Physical fitness
Blood factors
Discussion
Conclusions