Children's Weight Gain and Cardiovascular Fitness Loss over the Summer

Physical Activity and Sedentary Time Among U.S. Adolescents Before and During COVID-19: Findings From a Large Cohort Study

Introduction

Evidence suggests that adolescents engage in less physical activity during the summer break. Less is known regarding physical activity during the summer months of the COVID-19 pandemic.

Methods

Utilizing data from the Adolescent Brain Cognitive Development study, the authors examined daily activity measured by Fitbit Charge 2 devices before and after the onset of the COVID-19 pandemic during school and summer months. Linear models estimated activity during pre-COVID-19 school, pre-COVID-19 summer, COVID-19 school, and COVID-19 summer.

Results

Participants (N=7,179, aged 11.96 years, 51% female, 51% White) accumulated 8,671.0 (95% CI=8,544.7; 8,797.3) steps, 32.5 (95% CI=30.8, 32.3) minutes of moderate-to-vigorous physical activity, and 507.2 (95% CI=504.2, 510.2) minutes of sedentary time. During COVID-19 school, adolescents accumulated fewer daily steps and minutes of moderate-to-vigorous physical activity (-1,782.3 steps [95% CI= -2,052.7; -1,511.8] and -6.2 minutes [95% CI= -8.4, -4.0], respectively). Adolescents accumulated more minutes of daily sedentary time (29.6 minutes [95% CI=18.9, 40.3]) during COVID-19 school months than during the pre-COVID-19 school months. During pre-COVID-19 summer months, adolescents accumulated 1,255.1 (95% CI=745.3; 1,765.0) more daily steps than during COVID-19 months. Boys accumulated more daily steps and moderate-to-vigorous physical activity (2,011.5 steps [95% CI=1,271.9; 2,751.0] and 7.9 minutes [95% CI=1.4, 14.4], respectively) during the summer before COVID-19 than in summer during COVID-19. Both girls and boys accumulated more minutes of sedentary time during COVID-19 school months (47.4 [95% CI=27.5, 67.3] and 51.2 [95% CI=22.8, 79.7], respectively) than during COVID-19 summer months.

Conclusions

Societal restrictions during COVID-19 negatively impacted activity levels in the U.S., particularly during the summer months during COVID-19.

Changes in fitness and fatness in Australian schoolchildren during the summer holidays: fitness lost, fatness regained? A cohort study

BACKGROUND

Emerging evidence suggests that children's fatness increases and fitness declines at a greater rate during the summer holiday period, compared with the school year. The aim of this study was to compare rates of change in fitness and fatness over the in-term and summer holiday periods among Australian schoolchildren. A secondary aim was to explore whether rates of change differed according to the child's sex, socio-economic status (SES), pubertal status and weight status.

METHODS

Children (n = 381) initially in Grade 4 (age 9) were recruited for this 2-year longitudinal study. Fatness (% body fat, BMI z-score, waist-to-height ratio) and fitness (20-m shuttle run and standing broad jump) were measured at the start and end of two consecutive years. Rates of change were calculated for the two in-school periods (Grades 4 and 5) and for the summer holiday period. Rates of change in fatness and fitness between in-school and holiday periods were compared, and differences in rates of change according to sex, socio-economic status, and weight status were explored.

RESULTS

During the holidays, percentage body fat increased at a greater rate (annualised rate of change [RoC]: +3.9 vs. Grade 4 and + 4.7 vs. Grade 5), and aerobic fitness declined at a greater rate (RoC - 4.7 vs. Grade 4 and - 4.4 vs. Grade 5), than during the in-school periods. There were no differences in rates of change for BMI z-score, waist-to-height ratio or standing broad jump. Body fatness increased faster in the holidays (relative to the in-school period) in children who are overweight and from low-SES families. Aerobic fitness declined more rapidly in the holidays in children who are overweight.

CONCLUSION

This study highlights that during the summer holiday period, children experience greater increases in fatness and declines in fitness, with children who live with low-SES families and are overweight being more affected. The findings suggest the need for targeted interventions during this period to address these negative health trends.

TRIAL REGISTRATION

Australia New Zealand Clinical Trials Registry, identifier ACTRN12618002008202. Retrospectively registered on 14 December 2018.

Effects of a Summer Physical Activity Program on Fitness and Cognitive Function among Children from Low Socioeconomic Households

During the summer months, school aged children experience a loss in academic gains made over the course of the school year, as well as engage in poorer health behaviors such as decreased physical activity and poor diet that can lead to excess weight gain. This study aimed to assess changes in body composition, fitness, and cognitive abilities in children from low-income households after a summer physical activity program and explored whether time spent in moderate to vigorous physical activity (MVPA) was related to these changes. Participant's (N = 77) body composition, aerobic fitness (i.e., PACER), and cognitive function (i.e., modified flanker task) were measured during week 1 and week 3. MVPA was collected via hip accelerometer worn during program hours. Paired t-tests and regression analyses were conducted to determine changes between week 1 and 3, whether participation was related to changes in fitness, adiposity, and cognitive function. T-tests revealed significant changes in PACER score (10.71 ± 7.72 to 13.301 ± 10.68; p < 0.001) and incongruent accuracy on the flanker task (65.94% ± 23.83 to 69.00% ± 21.89; p < 0.006), however no significant change in BMI-for-age percentile or body fat percentage was detected. Additionally, regression analyses revealed no significant relationship between change in MVPA or attendance, and changes in PACER, flanker task performance, BMI, or body fat percentage. Children that participated in a summer physical activity program targeted toward children affected by poverty exhibited significant improvements in cardiorespiratory fitness and cognitive abilities, and no changes in body composition.

A Community Guide Systematic Review: School Dietary and Physical Activity Interventions

CONTEXT

Schools can play an important role in supporting a healthy lifestyle by offering nutritious foods and beverages and providing opportunities for physical activity. A healthy diet and regular physical activity may reduce the risk of obesity. This manuscript reports on a Community Guide systematic review examining the effectiveness of interventions in schools combining school meal or fruit and vegetable snack programs and physical activity.

EVIDENCE ACQUISITION

Studies meeting the intervention definition were identified from a literature search (search period: January 1990-November 2019). Community Guide systematic review methods were used to assess effectiveness as measured by dietary behavior, physical activity, and weight changes; analyses were conducted in 2020.

EVIDENCE SYNTHESIS

Interventions (n=24 studies) were considered effective for increasing physical activity (median increase=21.8 minutes/day; interquartile interval= -0.8 to 27.4 minutes/day), modestly increasing fruit and vegetable intake (median relative increase=12.1%; interquartile interval= -4.6%, 73.4%), and decreasing the prevalence of overweight and obesity (median decrease=2.5 percentage points; interquartile interval= -8.1, -1.6 percentage points) among elementary school students through sixth grade. There were not enough studies to determine the effectiveness of interventions for middle- and high-school students.

CONCLUSIONS

School meal or fruit and vegetable snack interventions combined with physical activity were effective in increasing physical activity, with modest effects for improving fruit and vegetable consumption and reducing the prevalence of overweight and obesity among elementary students. These results may inform researchers and school administrators about healthy eating and physical activity interventions.

Association of Recess Provision With Elementary School-Aged Children's Physical Activity, Adiposity, and Cardiorespiratory and Muscular Fitness

PURPOSE

To identify associations between amount of school recess provision and children's physical activity (PA), weight status, adiposity, cardiorespiratory endurance, muscular strength, and muscular endurance.

METHOD

Data from 6- to 11-year-old participants (n = 499) in the 2012 National Youth Fitness Survey were analyzed. Parents/guardians reported children's PA levels and recess provision, categorized as no/minimal (9.0%), low (26.1%), medium (46.0%), or high (18.9%). Children wore a wrist-worn accelerometer for 7 days and completed anthropometric measurements. Fitness was assessed using grip strength and treadmill, pull-up, and plank tests. Cross-sectional linear and logistic regression compared outcomes across levels of recess provision adjusting for the survey's complex sampling design.

RESULTS

Children with high provision of recess were 2.31 times more likely to meet PA guidelines according to parent report than those with no/minimal recess. Accelerometer-measured PA followed a more U-shaped pattern, wherein PA was higher in children with high, compared to low, recess provision but comparable to those with no/minimal recess provision. There were no associations with weight status, adiposity, or fitness.

CONCLUSION

Current recess recommendations (20 min·d-1) may be insufficient as 30 minutes per day of recess was associated with a 2-fold greater likelihood of achieving recommended PA levels. Additional research on recess quantity and quality is needed.

The effect of school year and summer break in health-related cardiorespiratory fitness: A 2-year longitudinal analysis

This study aimed to assess the trends of health-related cardiorespiratory fitness (CRF) during two school years with a 3-month summer break in children and adolescents. A 2-year longitudinal study, including 440 6th to 8th graders (218 boys), mean age 12.3 years, was conducted. The Progressive Aerobic Cardiovascular Endurance Run (PACER) was used to assess CRF. Physical activity was measured using accelerometers. Repeated measures linear models were used to analyses differences and trends in VO2peak and health-related CRF. Overall differences between time-point VO2peak were significant for both boys (p<0.001) and girls (p=0.003). Pairwise comparisons showed that VO2peak improved from the beginning to the end of the same school year for boys (school-year 1: 1.53 ml/kg/min, 95%CI=0.98, 2.09; school-year 2: 1.81 ml/kg/min, 95%CI=1.28, 2.34) and girls (school-year 1: 0.85 ml/kg/min, 95%CI=0.43, 1.27; school-year 2: 1.05 ml/kg/min, 95%CI=0.73, 1.36), while, differences in CRF during summer break were not significant. However, significance was only maintained for girls when performing monthly adjusted analysis. Improvements in CRF were observed during school year and remained unchanged during summer break. These findings provide relevant information for the health education community, suggesting the need for additional efforts to counteract the summer break effects on CRF, especially for girls.

Recess and Overweight and Obesity in Children 5-11 Years of Age: 2013-2016 National Health and Nutrition Examination Survey

BACKGROUND

Recess has been shown to increase total daily energy expenditure, which may favorably impact body mass index by decreasing adiposity. This study examines associations between recess participation and adiposity.

METHODS

The study sample included male (N = 1434) and female (N = 1409) children 5 to 11 years of age participating in the 2013-2016 National Health and Nutrition Examination Survey. Overweight and obesity were defined using age- and sex-specific percentiles. Recess participation interview questions were answered via proxy response.

RESULTS

Compared to a referent group participating in recess 5 days/week for >30 minutes/day and independent of demographic and behavioral factors, analysis revealed significantly greater odds of obesity in females reporting no recess participation (odds ratio 1.80; 95% confidence interval, 1.03-3.15, p = .03). Furthermore, minority females were consistently found to possess greater odds of overweight and obesity independent of recess participation time. Only Mexican American boys were found to have greater odds of obesity independent of participation recess time.

CONCLUSIONS

In a large nationally representative sample of US children, reporting no recess was associated with significantly greater odds of obesity in females. Minority females were also more likely to be overweight and obese and Mexican American boys are more likely to be obese independent of recess participation time.

Impact of Year-Round and Traditional School Schedules on Summer Weight Gain and Fitness Loss

Background: Summer weight gain and fitness loss has been identified as a public health concern for children. The objective of this study was to compare changes in weight status and cardiovascular fitness in children attending year-round and traditional calendar schools. Methods: Participants were 321 children from a traditional and year-round school. BMI and Progressive Aerobic Cardiovascular Endurance Run (PACER) Laps were collected during school. Multilevel general linear mixed-effects models were utilized to examine changes in BMI and PACER over the summer while also considering summer camp and sport participation. Results: Children had higher BMI z-scores during Fall 2018 compared with Spring 2018 (b = 0.09, p = 0.006). This effect was modified by Break Length, as students with 3-week (b = -0.09, p = 0.012) and 7-week breaks (b = -0.10, p = 0.003) displayed attenuated increases in BMI z-scores compared with 12-week breaks. For PACER Laps, students who participated in summer sports displayed improvements compared with nonparticipants (b = 4.6 laps, p = 0.001). Conclusions: Shorter summer breaks appear to have a protective effect on summer weight gain when compared with a traditional 12-week break. In addition, children who participated in organized sport over the summer did see a significant improvement in cardiovascular fitness. Schools might consider a year-round school calendar for its potential to protect against summer weight gain.