Results from South Korea's 2018 Report Card on physical activity for children and youth.

BACKGROUND/OBJECTIVE: South Korea's 2018 Report Card on Physical Activity for Children and Youth is the second comprehensive evaluation of physical activity and the sources of influence based on the 10 core indicators provided by the Active Healthy Kids Global Alliance. It will serve as an advocacy tool to promote physical activity among children and youth. METHODS: Three national surveillance data (i.e., 2017 Korea Youth Risk Behavior Web-based Survey, 2016 Korea National Health and Nutrition Examination Survey, 2016 Physical Activity Promotion System) were used as main sources to evaluate the indicators. Descriptive statistics were performed to obtain prevalence estimates of physical activity-related indicators. In addition, expert opinions as well as the most recently available published or unpublished relevant sources were synthesized. RESULTS: South Korea's 2018 Report Card, compared to the 2016 Report Card, showed favourable changes in the Active Transportation (B+), Organized Sports Participation (C), Sedentary Behaviours (D), and School (D+) indicators, while unfavourable changes were shown in Overall Physical Activity (F) and Government (D). Physical Fitness was graded as D+. In parallel with the 2016 Report Card, Active Play, Family and Peers, and Community and Environment remain ungraded due to insufficient data. CONCLUSIONS: Successes as well as gaps and research needs were identified in the 2018 Report Card. Though some indicators have shown improvement, most children and youth continue to be insufficiently physically active with overall poor grades (Average of D+). To achieve substantial improvement in all grades in future Report Cards, more institutional and governmental support and investment is needed to promote physical activity. Furthermore, effort should be made to generate data pertaining to the indicators that were ungraded.

The Effects of Body Composition, Physical Fitness on Time of Useful Consciousness in Hypobaric Hypoxia.

INTRODUCTION: Several previous studies have reported that hypoxia accidents of fighter pilots are rarer than gravity-induced loss of consciousness and spatial disorientation; however, the risk is greater. Therefore, this study aimed to investigate the relationship between physical fitness and body composition on time of useful consciousness (TUC) in hypobaric hypoxia. MATERIALS AND METHODS: Body composition and physical fitness testing on human participants were performed; subsequently, they were exposed to hypobaric hypoxia at a simulated altitude of 25,000 ft. Cognitive testing of the participants was accomplished by having them perform arithmetic task tables until they stopped writing for a period exceeding 5 seconds, at which point, they were placed on 100% oxygen. TUC was measured from the time the participants removed their oxygen masks to the time when the oxygen masks were placed back on them. Pearson's correlation was used to determine the relationship between TUC and other variables, and multiple regression was performed to determine the independent variables that best explain the TUC. RESULTS: TUC was positively correlated with the maximum oxygen uptake, stroke volume, arteriovenous oxygen difference, and endurance (sit-up and push-up). The maximum heart rate on the ground, high altitude, body fat mass, and percent body fat were negatively correlated with TUC. A regression analysis showed that 84.5% of the TUC can be explained by body composition and physical fitness. CONCLUSIONS: Our results revealed that increased cardiorespiratory fitness and decreased body fat mass could significantly impact the TUC. Therefore, for Air Force pilots who are frequently at high altitudes and at risk for exposure to hypoxia, aerobic exercise is significant to hypoxia tolerance.

Joint association of aerobic physical activity and muscle-strengthening activities with metabolic syndrome : the Korean National Health and Nutrition Examination Survey 2014-2015.

OBJECTIVES: The study aimed to examine whether simultaneously meeting the combined guidelines of accelerometer-assessed moderate to vigorous physical activity (MVPA) and self-reported muscle-strengthening activity (MSA) was associated with lower odds of metabolic syndrome (MetS) than meeting neither or 1 of the guidelines among the Koreans. METHODS: This cross-sectional analysis included 1,355 participants from the Korea National Health and Nutrition Examination Survey (2014-2015). Logistic regression was used to analyze the associations across groups of MVPA-MSA guideline adherence (meeting neither [reference]; meeting MVPA only; meeting MSA only; meeting both MVPS and MSA) with MetS components (abdominal obesity, hypertriglyceridemia, low high-density lipoprotein cholesterol [HDL-C], hypertension, and hyperglycemia). The odds ratios (ORs) were adjusted for covariates (e.g., sex, age, body mass index, and accelerometer wearing time). RESULTS: MSA only significantly reduced the OR for abdominal obesity (OR, 0.34; 95% confidence interval [CI], 0.13 to 0.91). Meeting both MVPA and MSA reduced the OR for hypertriglyceridemia (OR, 0.59; 95% CI, 0.39 to 0.88) and low HDL-C (OR, 0.46; 95% CI, 0.31 to 0.68). Compared to meeting neither, MVPA only (OR, 0.63; 95% CI, 0.44 to 0.89) and both MVPA and MSA (OR, 0.46; 95% CI, 0.28 to 0.76) significantly reduced the OR for MetS. CONCLUSIONS: Combined MVPA-MSA was more beneficially associated with MetS prevalence than MVPA only and MSA only. Considering that more than 85% of Korean adults do not meet both the MVPA and MSA guidelines, public health actions to promote adherence should be supported.

Relationship of Physical Activity and Sedentary Time with Metabolic Health in Children and Adolescents Measured by Accelerometer: A Narrative Review.

The purpose of this study was to summarize the associations of physical activity (PA) and sedentary time (SED) with metabolic health and examine the effects of time reallocation on metabolic health in adolescents using accelerometer data. A literature search was conducted using PubMed, ScienceDirect, Web of Science, Cochran Library, and Google Scholar, and 27 articles were reviewed. Recent research generally confirms the associations of PA and SED with metabolic health. High PA levels and low SED levels had a positive relationship with metabolic health. Moreover, reallocating 10 min of daily SED to PA was associated with better metabolic health indicators. These results were stronger for moderate-to-vigorous physical activity than for light intensity PA. Thus, efforts to convert SED into PA of at least moderate intensity appear to be an effective strategy to prevent metabolic disease development in children and adolescents. However, some of the associations between PA and metabolic health indicators were inconsistent, depending on age, obesity degree, and PA intensity. Additionally, various accelerometer data collection and processing criteria impact the interpretation of the results. Therefore, consistent accelerometer data collection and analysis methods are needed in future studies. Further, intervention studies are required to verify the causality and effectiveness of the isotemporal substitution model.

Accelerometer-measured stepping cadence patterns in Korean adults: an analysis of data from the 2014-2015 Korea National Health and Nutrition Examination Survey.

OBJECTIVES: The aim of this study was to identify the stepping cadence patterns in Korean adults by using objectively measured accelerometer data to analyze the time spent in each cadence category by sex and age. METHODS: During the 2014-2015 Korean National Health and Nutrition Examination Survey, 1,703 males and females aged 19-64 years provided at least 1 valid day of data (wearing an accelerometer ≥ 10 hr/d). The mean cumulative time and percentage per day in 8 cadence categories (0, 1-19, 20-29, 30-59, 60-79, 80-99, 100-119, and ≥ 120 steps/min) by sex and age group were calculated. RESULTS: Cumulative time and percentage per day decreased across the incremental cadence categories. Participants spent 360.08± 2.56 min/d in the non-movement cadence category and 361.50± 2.28 min/d in the incidental movement cadence category. However, they spent only about 18.1 min/d (2.1%) at ≥ 100 steps/min. Males spent significantly more time in the cadence categories of sporadic movement, purposeful steps, slow walking, and medium walking, but the other categories, except for brisk walking, had higher values in females (p< 0.001). The older age group spent less time in non-movement cadence categories, and the youngest and oldest groups spent more time at a higher cadence (≥ 100 steps/min) than the other age groups. Similar patterns were found in a subgroup analysis by sex. CONCLUSIONS: Korean adults spent most of their time at a low cadence and only a few minutes at a high cadence (≥100 steps/min); this trend was consistent across sex and age groups.