The complex associations between adiposity, fitness, mental wellbeing and neurocognitive function after exercise: A randomized crossover trial in preadolescent children.

The aim of the present study was to examine the associations of adiposity and fitness on the preadolescent brain's response to acute exercise. In a sample of 58 children (ages 8-10; 19 females), demographic measures of age, sex, IQ, puberty, and socioeconomic status were considered. Children participated in a randomized crossover study, whereby they completed two different interventions; seated rest or treadmill walking, counterbalanced across participants. Associations between adiposity measures (standardized body mass index [BMI-Z], whole body percent fat [%Fat], visceral adipose tissue [VAT]), cardiorespiratory fitness measures (VO2max and Fat-Free VO2) were assessed on self-reported measures of mental wellbeing, and cognitive performance (response accuracy, reaction time) and neuroelectric (P3 amplitude and latency) indices of a Go/NoGo task following both exercise and rest interventions. Higher adiposity (whole-body percent fat, BMI-Z) was associated with higher trait anxiety (P's≤0.05) and disordered eating (P's≤0.05) scores. Higher fitness (VO2max) was associated with lower childhood depression scores (P=0.02). Regression analyses yielded specific post-exercise neurocognitive associations with adiposity-related (VAT, BMI-Z), and fitness-related (FF-VO2) outcomes, after controlling for post-rest neurocognitive outcomes. VAT was positively associated with post-exercise P3 ERP Latency for the Go task (P≤0.001); BMI-Z was negatively associated with P3 ERP amplitudes for the Go task (P's≤0.005); FF-VO2 was negatively associated with P3 ERP latency for the Go/NoGo task (P's≤0.05), and positively associated with NoGo task accuracy (P≤0.001). Overall, adiposity and fat-free fitness measures yield sensitive and differential associations with neurocognitive performance after exercise and after rest interventions.

Cross-sectional analysis reveals COVID-19 pandemic community lockdown was linked to dysregulated cortisol and salivary alpha amylase in children.

The COVID-19 pandemic altered everyday life starting in March 2020. These alterations extended to the lives of children as their normal routines were disrupted by community lockdowns, online learning, limited in-person social contact, increased screen time, and reduced physical activity. Considerable research has investigated the physical health impact of COVID-19 infection, but far fewer studies have investigated the physiological impact of stressful pandemic-related changes to daily life, especially in children. The purpose of this study was to leverage an ongoing clinical trial to investigate physiological consequences associated with chronic stress of pandemic community lockdown on children. As a part of the clinical trial, children provided saliva samples. Saliva samples were analyzed for cortisol and salivary alpha amylase (sAA) content. This secondary cross-sectional analysis included 94 preadolescent children located within the Greater Boston, Massachusetts community. Children participated in the study either before, during, or following the pandemic community lockdown to form three groups for comparison. In response to chronic stress caused by the pandemic community lockdown, participants demonstrated dysregulation of fast-acting catecholamine response of the locus-coeruleus-norepinephrine system and slower-acting glucocorticoid response, resulting in an asymmetrical relationship of hypocortisolism (M = 0.78 ± 0.19 µg/mL, p < 0.001) paired with higher sAA (M = 12.73 ± 4.06 U/mL, p = 0.01). Results suggest that the abrupt COVID-19 disruption to daily life, including the stressful experience of community lockdown, had physiological effects on typically developing children. Further research is required to investigate mental health outcomes of children following the chronic stress of the pandemic community lockdown.

Cardiorespiratory fitness levels and body mass index of pre-adolescent children and older adults during the COVID-19 pandemic.

Introduction: The social and behavioral effects of the COVID-19 pandemic have impacted the health and physiology of most people, including those never diagnosed with COVID-19. While the impact of the pandemic has been felt across the lifespan, its effects on cardiorespiratory fitness (commonly considered a reflection of total body health) of older adults and children may be particularly profound due to social distancing and stay-at-home advisories, as well as the closure of sport facilities and non-essential businesses. The objective of this investigation was to leverage baseline data from two ongoing clinical trials to determine if cardiorespiratory fitness and body mass index were different during COVID-19 relative to before COVID-19 in older adults and children. Methods: Healthy older individuals (N = 593; 65-80 years) and 200 typically developing children (8-10 years) completed a graded maximal exercise test and had their height and weight measured. Results: Results revealed that older adults and children tested during COVID-19 had significantly lower cardiorespiratory fitness levels than those tested before COVID-19 shutdowns (older adults: 30% lower; children: 53% lower; p's ≤ 0.001). In addition, older adults and children tested during COVID-19 had significantly higher BMI (older adults: 31.34 ± 0.57 kg/m2, p = 0.004; children: 19.27 ± 0.44 kg/m2, p = 0.05) than those tested before COVID-19 shutdowns (older adults: 29.51 ± 0.26 kg/m2, children: 18.13 ± 0.35 kg/m2). However, these differences in BMI did not remain significant when controlling for cardiorespiratory fitness. Discussion: Results from this investigation indicate that the COVID-19 pandemic, and behavior changes taken to reduce potential exposure, may have led to lower cardiorespiratory fitness levels in older adults and children, as well as higher body mass index. These findings provide relevant public health information as lower cardiorespiratory fitness levels and higher body mass indexes recorded during the pandemic could have far-reaching and protracted health consequences. Public health guidance is needed to encourage physical activity to maintain cardiorespiratory fitness and healthy body composition. Clinical trial registration: Older adults: https://clinicaltrials.gov/ct2/show/NCT02875301, identifier: NCT02875301; Children: https://clinicaltrials.gov/ct2/show/NCT03592238, identifier: NCT03592238.

Aerobic Fitness, B-Vitamins, and Weight Status Are Related to Selective Attention in Children.

There is an increasing prevalence of poor health behaviors during childhood, particularly in terms of physical activity and nutrition. This trend has occurred alongside a growing body of evidence linking these behaviors to cognitive function. B-vitamins are thought to be particularly important in the neural development that occurs during pregnancy, as well as in healthy cognitive aging. However, much less is known regarding the role of B-vitamins during childhood. Given that preadolescent childhood is a critical period for cognitive development, this study investigated the relationship between specific aspects of nutrition, particularly B-vitamins, and related health factors (e.g., body mass, fitness) on selective attention in children. Children (n = 85; 8-11 years) completed a selective attention task to assess inhibition. Participant's dietary intake was collected using the Automated Self-Administered 24-h dietary assessment tool. Correlations between specific nutrients, BMI, fitness, and task performance were investigated. After accounting for demographic variables and total caloric intake, increased B-vitamin intake (i.e., thiamin and folic acid) was associated with shorter reaction times (p's < 0.05), fitness was associated with greater response accuracy (p < 0.05), and increased BMI was related to increased variability in reaction times (p < 0.05). Together, these findings suggest that aspects of health may have unique contributions on cognitive performance. Proper physical health and nutrition are imperative for effective cognitive functioning in preadolescent children. Targeted efforts aimed at health education amongst this population could ensure proper cognitive development during school-age years, providing a strong foundation throughout life.