An External Focus of Attention is Effective for Balance Control when Sleep-deprived.

The purpose of our study was to examine if the beneficial effects of an external focus are effective for balance control when sleep-deprived. Sleep-deprived participants (27 hours awake) completed three blocks of five separate 30 second trials on a dynamic balance board. All participants were given internal, external, and control instruction. For the internal focus trials, participants focused on their feet; whereas, for the external focus trials, participants focused on the balance board. Participants' time in balance was significantly greater during the external focus compared to the internal focus and control. These findings suggest that external focus instructions are effective when participants are sleep-deprived.

The effects of low-intensity cycling on cognitive performance following sleep deprivation.

This study examined the effect of 24h of sleep deprivation on cognitive performance and assessed the effect of acute exercise on cognitive performance following sleep deprivation. Young, active, healthy adults (n=24, 14 males) were randomized to control (age=24.7±3.7years, BMI=27.2±7.0) or exercise (age=25.3±3.3years, BMI=25.6±5.1) groups. Cognitive testing included a 5-min psychomotor vigilance task (PVT), three memory tasks with increasing cognitive load, and performance of the PVT a second time. On morning one, cognitive testing followed a typical night's sleep. Following 24-h of sustained wakefulness, cognitive testing was conducted again prior to and after the acute intervention. Participants in the exercise condition performed low-intensity cycling (∼40%HRR) for 15-min and those in the control condition sat quietly on the bike for 15-min. t-Tests revealed sleep deprivation negatively affected performance on the PVT, but did not affect memory performance. Following the acute intervention, there were no cognitive performance differences between the exercise and rested conditions. We provide support for previous literature suggesting that during simple tasks, sleep deprivation has negative effects on cognitive performance. Importantly, in contrast to previous literature which has shown multiple bouts of exercise adding to cognitive detriment when combined with sleep deprivation, our results did not reveal any further detriments to cognitive performance from a single-bout of exercise following sleep deprivation.

Vagal Regulation of Cardiac Function in Early Childhood and Cardiovascular Risk in Adolescence.

OBJECTIVE: Poor behavioral self-regulation in the first 2 decades of life has been identified as an important precursor of disease risk in adulthood. However, physiological regulation has not been well studied as a disease risk factor before adulthood. We tested whether physiological regulation at the age of 2 years, in the form of vagal regulation of cardiac function (indexed by respiratory sinus arrhythmia [RSA] change), would predict three indicators of cardiovascular risk at the age of 16 years (diastolic and systolic blood pressure and body mass index). METHODS: Data came from 229 children who participated in a community-based longitudinal study. At the age of 2 years, children were assessed for RSA baseline and RSA change (ln(ms)) in response to a series of challenge tasks. These same children were assessed again at the age of 16 years for diastolic and systolic blood pressure (millimeters of mercury), height (meters), and weight (kilogram). RESULTS: Regression analyses revealed that less RSA withdrawal at the age of 2 years predicted higher diastolic blood pressure at the age of 16 years, adjusting for demographic characteristics (B = -3.07, M [S E] = 1.12, p = .006). Follow-up analyses demonstrated that these predictions extended to clinically significant levels of diastolic prehypertension (odds ratio = 0.43, 95% confidence interval = 0.22-0.89). RSA withdrawal did not significantly predict adolescent body mass index or systolic blood pressure. CONCLUSIONS: Vagal regulation of cardiac function in early childhood predicts select indicators of cardiovascular risk 14 years later. Early signs of attenuated vagal regulation could indicate an increased risk for elevated blood pressure before adulthood. Future research should test biological, behavioral, and psychological mechanisms underlying these long-term predictions.

Childhood temperament predictors of adolescent physical activity.

BACKGROUND: Physical inactivity is a leading cause of mortality worldwide. Many patterns of physical activity involvement are established early in life. To date, the role of easily identifiable early-life individual predictors of PA, such as childhood temperament, remains relatively unexplored. Here, we tested whether childhood temperamental activity level, high intensity pleasure, low intensity pleasure, and surgency predicted engagement in physical activity (PA) patterns 11 years later in adolescence. METHODS: Data came from a longitudinal community study (N = 206 participants, 53% females, 70% Caucasian). Parents reported their children's temperamental characteristics using the Child Behavior Questionnaire (CBQ) when children were 4 & 5 years old. Approximately 11 years later, adolescents completed self-reports of PA using the Godin Leisure Time Exercise Questionnaire and the Youth Risk Behavior Survey. Ordered logistic regression, ordinary least squares linear regression, and Zero-inflated Poisson regression models were used to predict adolescent PA from childhood temperament. Race, socioeconomic status, and adolescent body mass index were used as covariates. RESULTS: Males with greater childhood temperamental activity level engaged in greater adolescent PA volume (B = .42, SE = .13) and a 1 SD difference in childhood temperamental activity level predicted 29.7% more strenuous adolescent PA per week. Males' high intensity pleasure predicted higher adolescent PA volume (B = .28, SE = .12). Males' surgency positively predicted more frequent PA activity (B = .47, SE = .23, OR = 1.61, 95% CI: 1.02, 2.54) and PA volume (B = .31, SE = .12). No predictions from females' childhood temperament to later PA engagement were identified. CONCLUSIONS: Childhood temperament may influence the formation of later PA habits, particularly in males. Boys with high temperamental activity level, high intensity pleasure, and surgency may directly seek out pastimes that involve PA. Indirectly, temperament may also influence caregivers' perceptions of optimal activity choices for children. Understanding how temperament influences the development of PA patterns has the potential to inform efforts aimed at promoting long-term PA engagement and physical health.

Rationale, design and methods for the RIGHT Track Health Study: pathways from childhood self-regulation to cardiovascular risk in adolescence.

BACKGROUND: Cardiovascular risk factors during adolescence-including obesity, elevated lipids, altered glucose metabolism, hypertension, and elevated low-grade inflammation-is cause for serious concern and potentially impacts subsequent morbidity and mortality. Despite the importance of these cardiovascular risk factors, very little is known about their developmental origins in childhood. In addition, since adolescence is a time when individuals are navigating major life changes and gaining increasing autonomy from their parents or parental figures, it is a period when control over their own health behaviors (e.g. drug use, sleep, nutrition) also increases. The primary aim of this paper is to describe the rationale, design and methods for the RIGHT Track Health Study. This study examines self-regulation as a key factor in the development of cardiovascular risk, and further explores health behaviors as an explanatory mechanism of this association. We also examine potential moderators (e.g. psychosocial adversities such as harsh parenting) of this association. METHOD/DESIGN: RIGHT Track is a longitudinal study that investigates social and emotional development. The RIGHT Track Health Study prospectively follows participants from age 2 through young adulthood in an effort to understand how self-regulatory behavior throughout childhood alters the trajectories of various cardiovascular risk factors during late adolescence via health behaviors. Individuals from RIGHT Track were re-contacted and invited to participate in adolescent data collection (~16.5, 17.5 and 18(+) years old). Individuals completed assessments of body composition, anthropometric indicators, fitness testing (via peak oxygen consumption), heart rate variability during orthostatic challenge, 7-day accelerometry for physical activity and sleep, 24-h dietary recalls, and blood analysis for biomarkers related to metabolic syndrome, inflammatory status and various hormones and cytokines. Individuals also completed extensive self-report measures on diet and eating regulation, physical activity and sedentary behaviors, sleep, substance use, medical history, medication use and a laboratory-day checklist, which chronicled previous day activities and menstrual information for female participants. DISCUSSION: Insights emerging from this analysis can help researchers and public health policy administrators target intervention efforts in early childhood, when preventing chronic disease is most cost-effective and behavior is more malleable.

Assessing Walking Activity in Older Adults: Development and Validation of a Novel Computer-Animated Assessment Tool.

BACKGROUND: Assessing volume of physical activity (PA) in older adults is critical to understanding the role that PA has on health outcomes and the effectiveness of treatment interventions to increase PA. The purpose of this study was to investigate the psychometric properties of a novel computer-animated self-report questionnaire designed to assess walking activity of older adults: the Mobility Assessment Tool for Walking--the MAT-W. METHODS: We recruited 249 older adults (66.9±4.7 years, 71% female, 32% black) with cardiovascular disease and/or metabolic syndrome as part of the Cooperative Lifestyle Intervention Program-II study. Participants completed the MAT-W at baseline and after 6 months of a walking and weight loss (n = 78) or weight loss only (n = 69) intervention. Test-retest reliability was assessed in 31 participants. Walking speed at usual and fast pace was measured using a GAITRite mat, and 7-day accelerometry data were collected at baseline and 6 months. The mCHAMPS5, a modified version of a widely used self-report PA questionnaire, was completed at baseline. RESULTS: The test-retest reliability of MAT-W was excellent (intraclass correlation coefficient > .85). The MAT-W was correlated with mCHAMPS5 (Spearman r = .66, p < .001) and moderate/vigorous levels of PA as assessed by accelerometry (Spearman r = .65, p < .001) and was responsive to an intervention-induced change in PA at 6 months when comparing the Cooperative Lifestyle Intervention Program-II walking and weight loss group with the weight loss only group (p < .001). CONCLUSION: The MAT-W is a brief, reliable, and valid tool to assess PA and has promise for the assessment of walking behavior in older adults under free-living conditions.

The Cooperative Lifestyle Intervention Program-II (CLIP-II): design and methods.

A complication of cardiovascular disease (CVD) and the metabolic syndrome (MetS) among older adults is loss of mobility. The American Heart Association has identified weight management as a core component of secondary prevention programs for CVD and is an important risk factor for physical disability. The American Society for Nutrition and the Obesity Society have highlighted the need for long-term randomized clinical trials to evaluate the independent and additive effects of diet-induced weight loss (WL) and physical activity in older persons on outcomes such as mobility, muscle function, and obesity related diseases. Here we describe the rationale, design, and methods of a translational study, the Cooperative Lifestyle Intervention Program-II (CLIP-II). CLIP-II will randomize 252 obese, older adults with CVD or MetS to a weight loss only treatment (WL), aerobic exercise training (AT)+WL, or resistance exercise training (RT)+WL for 18 months. The dual primary outcomes are mobility and knee extensor strength. The interventions will be delivered by YMCA community partners with our staff as trainers and advisers. This study will provide the first large scale trial to evaluate the effects of diet-induced WL on mobility in obese, older adults with CVD or MetS as compared to WL combined with two different modes of physical activity (AT and RT). Because uncertainty exists about the best approach for promoting WL in older adults due to concerns with the loss of lean mass, the design also permits a contrast between AT+WL and RT+WL on muscle strength.