Purpose The purpose of this study was to develop the new indirect method assessing maximal oxygen uptake (VO2max) using heart rate (HR) and accelerometer during walk exercise. Methods One hundred seven participants (55 male, 52 female) performed a graded exercise test to determine VO2max and two types of 1,600 m walk exercises (fast walk and pace controlled walk). The equations for estimating VO2max was developed by stepwise multiple regression. The validity of developed equations tested through the correlation between measured VO2max and estimated VO2max, was assessed by predicted residual sum of squares, and Bland-Altman plotting. Results VO2maxwas correlated with time, and HR/activity count per minute (ACM) measured in pace controlled walk exercise at all distance (400 m, 800 m, 1,200 m, 1,600 m). The equations were valid significantly and their multiple correlation coefficients or standard estimated error were similar to that Åstrand-Rhyming cycle ergometer test or Rockport 1 mile walk test. Using HR/ACM in pace controlled walk (400 m), it was possible to estimate VO2max(R2: 0.675, %SEE: 10.7). The equation was: VO2max=121.659+6.656×Gender-0.865×Age-9.540×Time-2460.952×HR/ACM (Gender, 0=female, 1=male: Time, hundredth of a minute: HR, heart rate: ACM, activity count per minute). Conclusion Estimation equations developed in this study are considered to estimate VO2max through a shorter distance, or a lower intensity of walk exercise. It is required studies to target a wide range of ages or to develop walk test on a lower bpm.
Purpose The purpose of this study was to evaluate the moderate to vigorous physical activity(MVPA) and sedentary time measured by accelerometer. Furthermore, the level of physical activity and adherence rate of physical activity guideline(PAG) were compared with the self-reported questionnaire. Methods The MVPA, sedentary time, and adherence rate of PAG according to age and sex were examined to people who agreed to wear accelerometers among the participants of the 2014-2015 Korea National Health and Nutrition Examination Survey. To compare the relationship between accelerometer and self-reported questionnaire, Chi-squared test and Spearman correlation analysis were performed. Results The MVPA of the accelerometer-total(AT) was 40.6 minutes/day for men and 31.1 minutes/day for women. Sedentary time was 502.9 minutes/day for men and 498.9 minutes/day for women. The MVPA of accelerometer-bout(AB) estimates was 16.4 minutes/day for men and 14.2 minutes for women. On the other hand, the MVPA of the self-report was 95.8 minutes for men and 64.3 minutes for women, and the sedentary time was 471.2 minutes for men and 455.2 minutes for women. The adherence rate of PAG was 55.6% of the self-report, 56.1% of the AT, and 21.4% of the AB. The correlation between self-report and accelerometer was statistically significant(p < 0.01), but showed a weak correlation coefficient(rho=0.112-0.351). There was no association between AB and self-report(p < 0.01). The sensitivity and specificity of the self-report were 71.3% and 48.6%, respectively. The positive and negative predictive values of the self-report were 27.5% and 86.1%, respectively. Conclusions As a result of this study, self-reported physical activity level by questionnaire had more MVPA and less sedentary time than the accelerometer-determined physical activity. In addition, the adherence rate of the PAG differed from accelerometer and self-report. The difference was significantly increased when comparing AB with the self-report. Therefore, great care must be taken when interpreting accelerometer and self-report questionnaire. Further research will be needed on specific methods that can be used by complementing the two measurement tools.
Purpose The purpose of this study was to investigate characteristics of levels of physical activity in considering gender and different types of competition-oriented physical activity classes using three-dimensional accelerometers. Methods A total of 981 students(505 male students, 476 female students) in six different types of physical education classes were participated in this study. All of the six different types of physical education classes were competition-oriented classes, and levels of physical activity were accessed by three-dimensional accelerometers. Data were analyzed using t-test and ANOVA. Results First, descriptive analyses of participation time of levels of physical activity showed that MVPA of physical education classes is 10.26 mins (22.89%) on average, and, MVPA showed differently in different types of physical education classes in the order of T ball(14.61 mins), flying disk(12.61 mins), soccer(10.78 mins), volley ball(10.56 mins), basketball(9.64 mins), and table tennis(5.73 mins). Second, female students showed significantly lower levels of MVPA in all the different types of physical education classes. Third, post-hoc analyses showed that significantly higher levels of MVPA were found in T ball physical education classes and significantly lower levels of MVPA were found in table tennis physical education classes, compared to other types of physical education classes. Conclusions MVPA in physical education classes is not satisfied with recommended MVPA, and MVPA in Korean physical education classes is lower than MVPA in same types of physical education classes in other countries. In addition, significant mean differences of MVPA are found between male and female students, and new sports physical education classes show higher levels of MVPA compared to classic sports physical education classes. These results indicate that competition oriented physical education classes widely used in Korea need to find ways to increase MVPA and to overcome different levels of MVPA between male and female students.
PURPOSE This study was designed to propose a quantitative base training evaluation method through alpine ski training monitoring using a triaxial accelerometer. METHODS Twelve Korean alpine ski athletes, six each in France and New Zealand, participated in this study. Activity data during training and daily living were collected for 7 days via the Actigraph GT9X. The collected data were downloaded through ActiLife Ver 6.13.1. Energy expenditure was calculated with Freedson (2011), and the resting metabolic rate was corrected using the Harris & Benedict (1918) formula. Further, the physical activity intensity classification criteria and METs formula of Freedson (1998) were used to classify hourly activity intensity. The collected data were organized by date, time, intensity, and energy expenditure using Microsoft Excel 2016. Differences between weekdays vs. weekends and skiing vs. physical training were analyzed through a paired sample t-test using Windows SPSS 23 with a significance level of a=.05. RESULTS First, both groups showed repetitive on and off high-intensity activities during scheduled ski training and competition. Second, moderate-intensity activities accounted for an average of 6-10%, and the weekly total time and intensity of MVPA was very high. Finally, the group from France showed differences in total energy expenditure during weekdays vs. weekends (p<.05) and the energy expenditure of both ski training and physical training during weekdays vs. weekends (p<.05). The New Zealand group showed a difference in total energy consumption during weekdays vs. weekends (p<.05). CONCLUSIONS A systematic training program based on quantitative training evaluation should be developed for alpine ski athletes to maintain proper rest and exercise intensity levels.
Purpose The purpose of this sequential mixed-method study is to compare the levels of Moderate to Vigorous Physical Activity (MVPA) between the students with intellectual disabilities and students without disabilities in different types of inclusive physical education classes and to understand why different levels of MVPA occur. Methods For this purpose, 17 students with intellectual disabilities and 102 students without disabilities participated in this study, and the levels of MVPA in inclusive physical education classes were accessed using thee dimensional accelerometers. The collected data were analyzed using independent sample t-test. To understand the different levels of MVPA identified in quantitative analysis, four teachers were interviewed. Results Results showed that different levels of MVPA were found in inclusive physical education classes, and this is because the students with intellectual disabilities had participation constraints and teachers did not have knowledge to deal with those constraints. Considering gender difference, only different levels of MVPA were found among male students, which could be stemmed from few opportunities of cooperative works between male students with intellectual disabilities and male students without disabilities. Considering types of inclusive physical education classes, significant different levels of MVPA were identified in tee ball classes. The reason for this could be that the rule of tee ball is too complicated and too many team tasks for the students with intellectual disabilities to understand and to execute. Conclusions Based on the results, practical teaching strategies to increase levels of MVPA of the students with intellectual disabilities are provided in the discussion section.
PURPOSE This study aimed to analyze physical activity (sedentary, light, moderate to vigorous physical activity [MVPA]) characteristics of middle school students based on region (urban and rural) and sex. METHODS Data were collected from 216 students across 6 middle schools located in medium-sized urban (3 schools) and rural areas (3 schools), and the relevant physical activity was measured using a three-dimensional accelerometer (GT3X model). The collected data were inputted into the SPSS 20.0, and descriptive analysis and two-way ANOVA based on region and gender were performed (<.05). RESULTS The descriptive statistical analysis resulted in the following achievement rate of the physical activity standard (MVPA 60 minutes/day): 9.4%. The two-way ANOVA showed that the main effect according to gender was found in sedentary activity (F=5.258), light activity (F=6.790), and MVPA (F=32.274); furthermore, the main effect according to region was found in light activity (F=10.888) and MVPA (F=7.876). Interaction effect according to region and gender was found at all intensities, and the gap between rural and urban in male students was larger compared to that of female students. CONCLUSIONS After COVID-19, the level of physical activity among adolescents has worsened; this study found the problem of "decrease in physical activity; increase in sedentary activity" to be more serious among male students in urban areas.
PURPOSE This study conducted a longitudinal analysis of physical activity levels and characteristics of middle-school boys and girls over a three-year period before and after the COVID-19 pandemic. METHODS This study used a sequential mixed-methods research design. In the quantitative study; three-dimensional accelerometers were used to measure weekly physical activity and sedentary time over three years (2019, 2020, and 2021) among 33 middle-school boys and girls, and the data were analyzed using repeated measures analysis of variance. In the qualitative study, data were collected and analyzed through focus group interviews with five participants. RESULTS The quantitative study indicated a significant increase in sedentary behavior and significant decrease in low-intensity activity and MVPA during the first year of the COVID-19 pandemic. In the second year of the pandemic, no significant difference was observed in sedentary behavior, low-intensity activity, and MVPA compared to the data collected in the first year. During the pandemic’s first year, qualitative study identified the following physical activity problems: “lockdowns,” “sedentarization of leisure,” and “reduced structured physical activity.” The following reasons were identified for the lack of improvement in physical activity during the second year: “intensified sedentary lifestyle habits,” “weak social networks,” and “lack of energy to exercise.” CONCLUSIONS The COVID-19 pandemic has led to a significant decrease in physical activity and a significant increase in sedentary behavior among middle-school students in South Korea, and even as the environments for physical activity have recovered, the physical activity problems of the early stages of the pandemic have not improved.
PURPOSE The purpose of this study was to analyze the level and characteristics of physical activity (sedentary, light, and MVPA) of high school students according to physical education (PE) class (DWPE: days with PE class, DNPE: days with no PE class) and sex. METHODS Data were collected on 147 students (65 male and 82 female) from four high schools in Seoul city, and physical activity was measured using a three-dimensional accelerometer. The collected physical activity data were input into SPSS 25.0, and the descriptive analysis and two-way ANOVA according to PE class and sex were performed. RESULTS The descriptive statistical analysis showed that 31% (40.7% male and 23.4% female) of participants met the recommended physical activity durations (MVPA of 60 min/day). In the two-way ANOVA, sedentary activity, light activity, and MVPA showed statistically significant main and interaction effects according to PE class and sex. According to the results of the interaction effect analysis, the gap in physical activity between DWPE and DNPE was large in male students. For male students, light activity and MVPA significantly increased on the day of the PE class, and sedentary activity significantly decreased. However, for female students, DWPE and DNPE did not differ significantly in all levels of physical activity. CONCLUSIONS In conclusion, the level of physical activity of Korean high school students was relatively low, and the effect of daily-life physical activity in the PE class was limited to male students. Accordingly, an alternative should be introduced to increase the physical activity of female high-school students through PE classes.
PURPOSE This study aimed to examine the associations between accelerometer-measured physical activity and both cardiometabolic disease risk factors and metabolic syndrome in Korean adults. METHODS We performed a retrospective cohort study with age-sex matched case-control using data from the 2014-2016 Korea National Health and Nutrition Examination Survey, which was administered to South Korean adults (n=320). Individuals were categorized into quartiles based on accelerometer-measured moderate-to-vigorous physical activity (MVPA). Demographic and physical characteristics, waist circumference, visceral adiposity index, blood pressure, lipid profiles, and TG/HDL-C were observed. The associations between MVPA status and cardiometabolic disease risk factors as well as metabolic syndrome were determined using multiple logistic regression. RESULTS For the waist circumference, SBP, DBP, MBP, visceral adiposity, triglyceride, and a surrogate estimate of insulin resistance, the Q1 and Q2 groups had higher means compared with the Q3 and Q4 groups. HDL-C was higher in the Q3 and Q4 groups compared to the Q1 and Q2 groups. Odds ratios for cardiometabolic disease risk factors and metabolic syndrome decreased in a curvilinear manner with the increasing quartile of MVPA. CONCLUSIONS Adults with higher MVPA participation were strongly associated with cardiometabolic disease risk factors and metabolic syndrome.
The purpose of this study was to explore Physically Activity Lifestyle pattern & constraints of high school girl in city, and then to propose P.A. promotional ways. I used International Physical Activity Questionnaire Long version and accelerometer to examine outline of P.A. pattern, and photo-voice as qualitative research techniques. The results were as followings. First, sedentary lifestyles of students in G girls' high school was terrible. Accelerometer was said that their inactive time were about 92.4%, however their moderate to vigorous time about 0.76% of the total time of a week. And, school domain of four domains(school, transportation, leisure, domestic chores) were the most active domain of all. Second, P.A. constraints were analyzed as 'because of something no'(time, effort, will, space, physical skills and person) and 'because of something'(smart phone, car, gaze, rules). The key cause were a shortage of time caused by academic based on school curriculum, sedentary leisure and transportation culture. Lastly, I proposed high school girl' P.A. promotional ways in basis of social ecological model.
