Associations of actigraphy-assessed sleep variables with adiposity and serum cardiometabolic outcomes in emerging adults.

This study assessed associations of actigraphy-assessed sleep with adiposity and serum cardiometabolic outcomes in emerging adults, and whether sex and race modified these associations. Data on 147 emerging adults (age = 19.4 ± 1.3 years; body mass index = 26.4 ± 7.0 kg m-2 ; 59% female; 65% White) from RIGHT Track Health were used. Actigraphy-based sleep measures included sleep duration, sleep efficiency, sleep timing midpoint, day-to-day sleep duration and sleep timing midpoint variability. Combined sleep duration and sleep timing behaviours were also derived (early-bed/late-rise, early-bed/early-rise, late-bed/late-rise, late-bed/early-rise). Outcomes included body mass index and BodPod-assessed fat mass index, fasting serum leptin, C-reactive protein, and homeostatic model assessment-insulin resistance. Sleep duration was 5.4 h per night. We noted an inverse association between sleep duration and homeostatic model assessment-insulin resistance. The early-bed/early-rise group had greater body mass index, C-reactive protein and homeostatic model assessment-insulin resistance compared with the early-bed/late-rise group (referent). Sex modified associations of sleep efficiency with C-reactive protein; stratified results revealed positive association between sleep efficiency and C-reactive protein in males, but not females. Race modified associations of sleep duration with body mass index and leptin, and of sleep duration variability with C-reactive protein. Stratified analyses revealed inverse associations between sleep duration with body mass index and leptin in Black, multiracial/other race individuals only. Positive association between sleep duration variability and C-reactive protein was noted in White individuals only. Shorter sleep duration, particularly when combined with earlier sleep timing, is associated with greater adiposity and serum cardiometabolic outcomes. Additional studies are needed to assess individual- and contextual-level factors that may contribute to sex and race differences in sleep health and cardiometabolic risk in emerging adults.

Longitudinal Associations Among Food Insecurity During Pregnancy, Parental Mental Health Symptoms, Controlling Feeding Styles, and Infant Food Responsiveness.

BACKGROUND: Research is needed to identify pathways by which household food insecurity (FI) contributes to parental controlling feeding styles and infant food responsiveness, 2 factors that play a role in shaping obesity risk across infancy and early childhood. OBJECTIVES: This longitudinal study tested the hypothesis that prenatal FI would be positively associated with higher infant food responsiveness via greater parental mental health symptomatology and controlling feeding styles (pressuring, restrictive). METHODS: Participants included a community sample of 170 birth parents and their infants participating in an ongoing longitudinal study. Parents self-reported household FI and mental health symptoms (depression and anxiety) during pregnancy. Postnatally, parents reported their mental health symptoms, their use of controlling feeding styles, and infant food responsiveness. Path analyses with bias-corrected 95% bootstrapped CIs tested direct and indirect associations between prenatal FI and infant food responsiveness. RESULTS: Prenatal FI was indirectly associated with higher infant food responsiveness via greater parental mental health symptomatology and pressuring to finish (b = 0.01; 95% CI: 0.001, 0.025). Prenatal FI was associated with greater parental mental health symptomatology across the peripartum period (ß = 0.54; P < 0.001), which in turn was associated with more pressuring to finish at 2 months pospartum (ß = 0.29; P = 0.01) and higher infant food responsiveness at 6 months (ß = 0.17; P = 0.04). There were no direct effects of prenatal FI on controlling feedings styles or infant food responsiveness. CONCLUSIONS: Our findings point to parental mental health as a potential pathway by which FI may be associated with obesity-promoting parental feeding styles and infant appetitive behaviors. In addition to ensuring reliable access to enough quality food during pregnancy, multipronged assistance that promotes emotional well-being during the peripartum period and clinical guidance on noncontrolling feeding styles could benefit parent and infant health and well-being.

Physiologic and Behavioral Correlates of Energy Intake in Emerging Adulthood: Cross-Sectional Analysis of the RIGHT Track Health Study.

BACKGROUND: Consistent findings have reported that FFM is associated with EI. However, conjoint assessments of physiologic (body composition, fasting serum leptin) and behavioral [eating behaviors and physical activity (PA)] correlates of EI during emerging adulthood have not been examined. OBJECTIVES: We assessed associations between physiologic and behavioral correlates of EI within the context of one another in emerging adults (18-28 years old). We also assessed these associations in a subsample after the removal of probable EI underreporters. METHODS: Cross-sectional data from 244 emerging adults (age = 19.6 ± 1.4 y; BMI = 26.4 ± 6.6 kg/m2; 56.6% female) from the RIGHT Track Health study were used. Measures included body composition (BOD POD), eating behaviors (Three-Factor Eating Questionnaire), objective and subjective PA (accelerometer-derived total activity counts and Godin-Shephard Leisure-Time Exercise Questionnaire), fasting serum leptin, and EI (three 24-hour dietary recalls). Correlates independently associated with EI were entered into a backward stepwise linear regression model. Correlates that met the criteria of P < 0.05 were retained. Analyses were repeated in a subsample after removing probable EI underreporters (n = 48). Effect modification by sex (male and female) and BMI (BMI < 25 kg/m2, BMI ≥ 25 kg/m2) categories was also assessed. RESULTS: In the full sample, FFM (ß: 18.4; 95% CI: 9.9, 26.8), leptin (ß: -84.8; 95% CI: -154.3, -15.4), dietary restraint (ß: -35.2; 95% CI: -59.1, -11.3), and subjective PA (ß: 2.5; 95% CI: 0.04, 4.9) were significantly associated with EI. After the removal of probable underreporters, only FFM remained significantly associated with EI (ß: 43.9; 95% CI: 27.2, 60.6). No evidence of effect modification by sex or BMI categories was noted. CONCLUSIONS: Although physiologic and behavioral correlates were associated with EI in the full sample, only FFM remained a robust correlate of EI in a subsample of emerging adults after removing probable EI underreporters.

Longitudinal associations between specific types of emotional reactivity and psychological, physical health, and school adjustment.

Using a multimethod, multiinformant longitudinal design, we examined associations between specific forms of positive and negative emotional reactivity at age 5, children's effortful control (EC), emotion regulation, and social skills at age 7, and adolescent functioning across psychological, academic, and physical health domains at ages 15/16 (N = 383). We examined how distinct components of childhood emotional reactivity directly and indirectly predict domain-specific forms of adolescent adjustment, thereby identifying developmental pathways between specific types of emotional reactivity and adjustment above and beyond the propensity to express other forms of emotional reactivity. Age 5 high-intensity positivity was associated with lower age 7 EC and more adolescent risk-taking; age 5 low-intensity positivity was associated with better age 7 EC and adolescent cardiovascular health, providing evidence for the heterogeneity of positive emotional reactivity. Indirect effects indicated that children's age 7 social skills partially explain several associations between age 5 fear and anger reactivity and adolescent adjustment. Moreover, age 5 anger reactivity, low-, and high-intensity positivity were associated with adolescent adjustment via age 7 EC. The findings from this interdisciplinary, long-term longitudinal study have significant implications for prevention and intervention work aiming to understand the role of emotional reactivity in the etiology of adjustment and psychopathology.

The effect of acute exercise on the cortisol awakening response.

The effects of acute exercise on the cortisol awakening response (CAR), characterized by the rapid increase in cortisol concentrations within the 30-45 min following sleep offset has yet to be fully elucidated. Thus, our study investigated the effects of late-evening acute exercise on the CAR the following morning. We hypothesized that exercise would have a significant effect on the CAR the following morning. Twelve participants (mean (SD): age = 23 (4) years; mass = 76.8 (8.7) kg; height = 175.6 (5.0) cm; [Formula: see text]O2max = 48.9 (7.5) ml.kg-1.min-1) reported to the laboratory in the evening (1800 h) on two occasions and were randomly assigned to either exercise for one hour (70-75% of maximal power output) or rest condition. Blood and saliva samples were assayed for cortisol. Mixed-effects models determined the effect of exercise on the cortisol response post-waking in both blood and saliva. Participants demonstrated an average exercise-induced increase in circulating cortisol of 477.3%, with actual mean (SD) heart rate relative to maximum of 87.04% (6.14%). Model results demonstrated a negative effect for exercise condition when modeling the serum and salivary cortisol responses to awakening via a quadratic growth model (serum, ßCondition = - 42.26 [95% CI - 64.52 to - 20.01], p < 0.001; saliva, ßCondition = - 11.55 [95% CI - 15.52 to - 7.57], p < 0.001). These results suggest that cortisol concentrations in saliva and blood are significantly lower the morning following a prior evening exercise session. Therefore, the CAR may serve as a useful biomarker to monitor responses to exercise training, although the underlying mechanism for these decreases in the CAR should be investigated further.

Associations among eating behaviors, food security status, and dietary intake during pregnancy.

Dietary intake of certain food groups and/or nutrients during pregnancy has been associated with maternal and infant pregnancy-related outcomes. Few studies have examined how behavioral and environmental factors interact to influence prenatal diet. We examined associations between eating behaviors (dietary restraint, emotional eating, external eating) and food security status regarding dietary intake of selected nutrients/food groups during pregnancy. Participants (N = 299; 29% Non-Hispanic Black; 16% ≤ high school education; 21% food insecure) completed validated questionnaires to assess estimated daily intake of food groups/nutrients during pregnancy [e.g., added sugars from sugar-sweetened beverages (SSBs), % of energy from fat, fruit and vegetable (FV) intake] via National Cancer Institute Dietary Screener Questionnaires); eating behaviors (Dutch Eating Behavior Questionnaire); and food security status (6-item USDA Food security Module). Separate hierarchical multiple regressions for each dietary outcome were conducted controlling for maternal age, education, income-to-needs, race/ethnicity, pre-pregnancy BMI, and gestational diabetes. A significant interaction was found between dietary restraint and food security status on added sugar intake from SSBs (ß = -0.15, p = 0.02). The negative association between restraint and added sugar from SSBs was stronger among food insecure participants (ß = -0.47, p < 0.001 vs. ß = -0.15, p = 0.03). Higher external eating (ß = 0.21, p < 0.01) and lower restraint (ß = -0.13, p = 0.03) were associated with higher % of energy from fat and living in a food insecure household (ß = -0.15, p = 0.01) was associated with lower FV intake. Understanding dietary intake during pregnancy requires consideration of the broader context in which eating behaviors occur.

Childhood Adversity Predicts Maternal Pre-Pregnancy BMI but not Gestational Weight Gain.

INTRODUCTION: Obesity and excessive weight gain during pregnancy have lasting implications for both women and infant health. Adverse childhood experiences and stressful life events have been associated with pre-pregnancy obesity and excessive gestational weight gain. However, the effect of each has been examined independently and scant work has investigated the effects of both in the same analysis. The current study examined the unique and conjoint effects of adverse childhood experiences and recent stressful life events on women's pre-pregnancy BMI and gestational weight gain. METHODS: A racially and socioeconomically diverse sample of 176 pregnant women completed questionnaires and anthropometric measurements during the third trimester and two months postpartum. RESULTS: Maternal adverse childhood experiences were uniquely associated with pre-pregnancy BMI (ß = 0.21, p = .02), but not gestational weight gain. Recent stressful life events did not uniquely predict pre-pregnancy BMI or gestational weight gain, nor did it explain the association between adverse childhood experiences and pre-pregnancy BMI. Adverse childhood experiences and recent stressful life events did not interact to predict either of the women's weight outcomes. DISCUSSION: Adverse childhood experiences have lasting unique effects on women's pre-pregnancy BMI. Obesity is related to several perinatal health issues for the mother and child, thus understanding the effects of childhood adversity on women's weight outcomes is critical. Routine screening for ACEs among women of childbearing age and pregnant women, paired with referrals and educational resources, can mitigate the deleterious effects of childhood adversity on women and infant health.

Interactive effects of maternal physiological arousal and regulation on maternal sensitivity: Replication and extension in an independent sample.

This study examined the extent to which mothers' physiological arousal (i.e., skin conductance level [SCL] augmentation) and regulation (i.e., respiratory sinus arrhythmia [RSA] withdrawal) interacted to predict subsequent maternal sensitivity. Mothers' (N = 176) SCL and RSA were measured prenatally during a resting baseline and while watching videos of crying infants. Maternal sensitivity was observed during a free-play task and the still-face paradigm when their infants were 2 months old. The results demonstrated that higher SCL augmentation but not RSA withdrawal predicted more sensitive maternal behaviors as a main effect. Additionally, SCL augmentation and RSA withdrawal interacted, such that well-regulated maternal arousal was associated with greater maternal sensitivity at 2 months. Further, the interaction between SCL and RSA was only significant for the negative dimensions of maternal behavior used to derive the measure of maternal sensitivity (i.e., detachment and negative regard) suggesting that well-regulated arousal is particularly important for inhibiting the tendency to engage in negative maternal behaviors. The results replicate findings from mothers in previous studies and demonstrate that the interactive effects of SCL and RSA in relation to parenting outcomes are not sample specific. Considering joint effects of physiological responding across multiple biological systems may enhance understanding of the antecedents of sensitive maternal behavior.

Maternal sleep problems, depression, and infant negative emotionality are associated with maternal feeding to soothe in early infancy.

Maternal overreliance on feeding to soothe to relieve infants' distress has been associated with higher rates of childhood obesity. Limited research has examined infant and maternal characteristics that predict maternal feeding to soothe. The goal of the present study was to examine the role of infant (temperament) and maternal (depression, sleep problems) characteristics as predictors of maternal feeding to soothe. Mothers (N = 176) completed the Food to Soothe Scale, the Infant Behavior Questionnaire-Revised Very Short Form, the Center for Epidemiological Studies Depression Scale, and the Pittsburgh Sleep Questionnaire when their infants were 6 months old. Hierarchical multiple regression was used. Maternal depression only predicted feeding to soothe among mothers receiving WIC benefits, and this association was no longer significant when maternal sleep problems were added to the model. Maternal sleep problems predicted higher feeding to soothe as a main effect and in interaction with infant negative emotionality, maternal depression, and to a lesser extent WIC status. Specifically, infant negative emotionality was only associated with greater feeding to soothe among mothers with higher sleep problems, and sleep problems were only associated with greater feeding to soothe among depressed mothers and mothers receiving WIC benefits. The findings suggest that addressing multiple stressors, including maternal sleep, in the early postnatal period may strengthen the effectiveness of early child obesity interventions that target maternal feeding behaviors.

Infant appetite and weight gain in early infancy: Moderating effects of controlling feeding styles.

Excessive infant weight gain is a strong predictor of later obesity. While controlling feeding has been linked to negative weight outcomes, research has not considered associations between infant appetite and maternal feeding simultaneously in relation to infant weight. This longitudinal study examined infant food responsiveness and slowness in eating as predictors of infant weight outcomes and tested controlling feeding styles (restrictive and pressuring) as moderators. Data came from a diverse sample of mothers and their infants participating in an ongoing longitudinal study. Mothers (n = 159) reported infant appetite and feeding styles at 2 postnatal timepoints (2-month visits and 6-month visits). The infant weight outcomes included change in weight-for-age z-scores (WAZ-change) and rapid weight gain (RIWG; WAZ-change ≥ 0.67 SD) from birth to the second postnatal visit. Data were analyzed using hierarchical multiple and logistic regressions, controlling for birthweight, gestational age, maternal race/ethnicity, feeding mode, and residing with an intimate partner. Over 25% of infants exhibited RIWG. Greater infant food responsiveness predicted both greater infant weight gain and RIWG status. Infant food responsiveness and slowness in eating interacted with controlling feeding styles in a unique way. Infants with higher food responsiveness whose mothers were less restrictive had greater weight gain (b = 0.61, p < 0.001) and increased probability of RIWG (b = 2.71, p < 0.01) than infants with more restrictive mothers. Higher slowness in eating was associated with a lower RIWG probability among infants of mothers with lower pressuring feeding (b = -1.86, p < 0.05). For infants with a large appetite, some level of restrictive feeding may be beneficial for preventing excessive weight gain while pressuring may exacerbate the positive association between faster eating and RIWG.

Cardio-Hypothalamic-Pituitary Coupling during Rest and in Response to Exercise.

The objective of this study was to examine cardio hypothalamic-pituitary coupling and to better understand how the temporal relations between these systems are altered during rest and exercise conditions. An intensive within subjects study design was used. Seven adult males completed two visits, each consisting of either a 24 h period of complete rest or a 24 h period containing a high-intensity exercise bout. An intravenous catheter was used to collect serum samples every 10 min throughout the 24 h period (i.e., 145 samples/person/condition) to assess growth hormone (GH) dynamics throughout the 24 h period. Cardiac dynamics were also collected throughout the 24 h period and epoched into 3 min windows every 10 min, providing serial short-time measurements of heart rate variability (HRV) concurrent to the GH sampling. The standard deviation of the normal RR interval (SDNN), the root mean square of successive differences (rMSSD), and sample entropy (SampEn) was calculated for each epoch and used to create new profiles. The dynamics of these profiles were individually quantified using SampEn and recurrence quantification analysis (RQA). To address our central question, the coupling between these profiles with GH was assessed using cross-SampEn and cross-RQA (cRQA). A comparison between the epoched HRV profiles indicated a main effect between profiles for sample entropy (p < 0.001) and several measures from RQA. An interaction between profile and condition was observed for cross-SampEn (p = 0.04) and several measures from cRQA. These findings highlight the potential application of epoched HRV to assess changes in cardiac dynamics, with specific applications to assessing cardio hypothalamic-pituitary coupling.

Examining Internal and External Physical Workloads Between Training and Competitive Matches Within Collegiate Division I Men's Soccer.

ABSTRACT: Anderson, T, Adams, WM, Martin, KJ, and Wideman, L. Examining internal and external physical workloads between training and competitive matches within collegiate Division I men's soccer. J Strength Cond Res 35(12): 3440-3447, 2021-A direct analysis comparing differences in the demands of competition relative to in-season training in Division I collegiate soccer players has yet to be reported. Thus, the primary purpose of this study was to compare the absolute and relative internal and external workloads measured during training with competitive matches. Twenty-six male college soccer players were monitored over 2 consecutive seasons using a GPS and heart rate (HR) telemetry system. Differences between outdoor training sessions and competitive matches were analyzed for internal and external absolute and relative training workloads. Differences in training workloads between the 3 days before a match were also analyzed. Absolute time in HR zone 4 (80-89% of HRmax) and 5 (90-100% of HRmax); accelerations in zone 1 (0.50-0.99 m·s-2), zone 2 (1.00-1.99 m·s-2), and zone 3 (2.00-2.99 m·s-2); all negative acceleration zones; training load; and estimated energy expenditure were greater in competition than training (p < 0.05). By contrast, when comparing training and competition values using metrics relative to session duration, relative workload in trainings were greater than competition for HR zone 1 (50-59% of HRmax), zone 2 (60-69% of HRmax), zone 3 (70-79% of HRmax), and zone 4 (80-89% of HRmax) and all acceleration and negative acceleration zones. In addition, absolute training workloads were generally greatest 3 days prior (p < 0.01), but not different 2 days before the competitive match. Absolute physical workloads of competition are significantly greater than those achieved during training; however, these differences and impact on the physical condition of players are mitigated by the greater relative workloads achieved during training. These results provide meaningful metrics that may lead to insights into proper conditioning and in-season workload management for Division I collegiate soccer programs.

The effect of physical activity on cognition relative to APOE genotype (PAAD-2): study protocol for a phase II randomized control trial.

BACKGROUND: By 2050, the prevalence of Alzheimer's disease (AD) in the United States is predicted to reach 13.8 million. Despite worldwide research efforts, a cure for AD has not been identified. Thus, it is critical to identify preventive strategies that can reduce the risk of or delay the onset of AD. Physical activity (PA) has potential in this regard. This randomized clinical trial aims to (a) test the causal relationship between PA and AD-associated cognitive function for persons with a family history of AD (FH+), (b) determine the moderating role of apolipoprotein epsilon 4 (APOE4) carrier status on cognition, and (c) assess cerebral structure, cerebral function, and putative biomarkers as mediators of the effects of PA on cognition. METHODS: We are recruiting cognitively normal, middle aged (40-65 years) sedentary adults with FH+. Participants are randomly assigned to a 12-month PA intervention for 3 days/week or to a control group maintaining their normal lifestyle. Saliva samples are taken at pre-test to determine APOE genotype. At pre-, mid-, and post-tests, participants complete a series of cognitive tests to assess information-processing speed, verbal and visual episodic memory, constructional praxis, mnemonic discrimination, and higher-order executive functions. At pre- and post-tests, brain imaging and blood biomarkers are assessed. DISCUSSION: We hypothesize that 1) the PA group will demonstrate improved cognition compared with controls; 2) PA-derived cognitive changes will be moderated by APOE4 status; and 3) PA-induced changes in neural and blood biomarkers will contribute to cognitive changes and differ as a function of APOE4 status. Our results may provide important insights into the potential of PA to preserve neurocognitive function in people with a heightened risk of AD due to FH+ and as moderated by APOE4 status. By using sophisticated analytic techniques to assess APOE as a moderator and neurobiological mechanisms as mediators across trajectories of cognitive change in response to PA, we will advance our understanding of the potential of PA in protecting against AD. TRIAL REGISTRATION: ClinicalTrials.gov NCT03876314. Registered March 15, 2019.

Diabetes risk status and physical activity in pregnancy: U.S. BRFSS 2011, 2013, 2015, 2017.

BACKGROUND: Pregnant women without complications are advised to engage in physical activity (PA) to mitigate adverse outcomes. Differences may exist among pregnant women of diverging diabetes status in meeting national PA recommendations. We sought to examine differences in aerobic activity (AA) and muscle strengthening activity (MSA) by diabetes risk status (DRS) among pregnant women in the United States. METHODS: The sample (n = 9,597) included pregnant women, age 18-44 years, who participated in the 2011, 2013, 2015, and 2017 Behavioral Risk Factor Surveillance System. Levels of DRS include: no diabetes (ND), high risk for diabetes (HRD) due to self-reported gestational diabetes or pre-diabetes, and overt diabetes due to self-reported, clinically diagnosed diabetes (DM). Odds ratios (ORs) and 95% confidence intervals (CI) for meeting PA recommendations were obtained. Covariates included age, race, education, household child count, alcohol consumption, and smoking status. RESULTS: Findings revealed that on average, DM had 46.5 fewer minutes of weekly AA compared to ND. Furthermore, a significantly lower OR (0.39; CI 0.19-0.82) for meeting both recommendations was observed in DM as compared to ND after adjustment. CONCLUSIONS: We observed that pregnant women with overt diabetes had a lower odds of engaging in PA, while those at high risk were similar in their PA engagement to ND. Future studies aimed at assessing determinants of PA behavior may help guide efforts to promote exercise in pregnant women with diabetes.

Protocol for iGrow (Infant Growth and Development Study): biopsychosocial predictors of childhood obesity risk at 2 years.

BACKGROUND: Childhood obesity remains a significant public health problem. To date, most research on the causes and correlates of obesity has focused on a small number of direct predictors of obesity rather than testing complex models that address the multifactorial nature of the origins of obesity in early development. We describe the rationale and methods of iGrow (Infant Growth and Development Study) which will test multiple pathways by which (a) prenatal maternal psychobiological risk predicts infant weight gain over the first 6 months of life, and (b) this early weight gain confers risk for obesity at age 2. Infant hormonal and psychobiological risk are proposed mediators from prenatal risk to early weight gain, though these are moderated by early maternal sensitivity and obesogenic feeding practices. In addition, higher maternal sensitivity and lower obesogenic feeding practices are proposed predictors of adaptive child self-regulation in the second year of life, and all three are proposed to buffer/reduce the association between high early infant weight gain and obesity risk at age 2. METHODS: iGrow is a prospective, longitudinal community-based study of 300 diverse mothers and infants to be followed across 5 data waves from pregnancy until children are age 2. Key measures include (a) maternal reports of demographics, stress, well-being, feeding practices and child characteristics and health; (b) direct observation of maternal and infant behavior during feeding, play, and distress-eliciting tasks during which infant heart rate is recorded to derive measures of vagal withdrawal; (c) anthropometric measures of mothers and infants; and (d) assays of maternal prenatal blood and infant saliva and urine. A host of demographic and other potential confounds will be considered as potential covariates in structural equation models that include tests of mediation and moderation. Efforts to mitigate the deleterious effects of COVID-19 on study success are detailed. DISCUSSION: This study has the potential to inform (1) basic science about early life processes casually related to childhood obesity and (2) development of targeted intervention and prevention approaches that consider mother, infant, and family risks and resources.

Variability and Complexity of Non-stationary Functions: Methods for Post-exercise HRV.

Heart rate variability (HRV) is a noninvasive marker of cardiac autonomic function that has been extensively studied in a variety of populations. However, HRV analyses require stationarity-thus, limiting the conditions in which these data can be analyzed in physiologic and health research (e.g. post-exercise). To provide evidence and clarity on how non-stationarity affects popular indices of variability and complexity. Simulations within physiologic (restricted to values similar to exercise and recovery RR-intervals) and non-physiologic parameters, with homoscedastic and heteroscedastic variances, across four sample lengths (200, 400, 800, and 2000), and four trends (stationary, positive-linear, quadratic, and cubic) were detrended using 1-3 order polynomials and sequential differencing. Measures of variability [standard deviation of normal intervals (SDNN) and root mean square of successive differences (rMSSD)] as well as complexity [sample entropy (SampEn)] were calculated on each of the raw and detrended time-series. Differential effects of trend, length, and fit were observed between physiologic and non-physiologic parameters. rMSSD was robust against trends within physiologic parameters while both SDNN and SampEn were positively and negatively biased by trend, respectively. Within non-physiologic parameters, the SDNN, rMSSD, and SampEn of the raw time-series were all biased, highlighting the effect of the scale between these two sets of parameters. However, indices of variability and complexity on the original (trended) times-series were furthest from those of the stationary time-series, with indices coming closer to the known values as fit become more optimal. Detrending with polynomial functions provide reliable and accurate methods of assessing the variability and complexity of non-stationary time-series-such as those immediately following exercise.

Temperamental vulnerability to emotion dysregulation and risk for mental and physical health challenges.

Emotion dysregulation characterizes many forms of psychopathology. Patterns of dysregulation occur as a function of a developmental process in which normative and adaptive emotion regulation skills fail to become part of the child's behavioral repertoire due to biological, psychological, and contextual processes and experiences. Here we highlight the processes involved in the dysregulation of temperamental anger and frustration that become core features of externalizing problems and place children at risk for more serious forms of psychopathology. We imbed these processes in a larger self-regulatory framework, and we discuss how they influence mental as well as physical health, using data from our 20-year longitudinal study following a large cohort of children into young adulthood. Recommendations are made for future research involving the integration of biological systems with mental and physical health outcomes.

Evaluation of a Goalkeeper-Specific Adaptation to the Yo-Yo Intermittent Recovery Test Level 1: Reliability and Variability.

Ehlert, AM, Cone, JR, Wideman, L, and Goldfarb, AH. Evaluation of a goalkeeper-specific adaptation to the Yo-Yo intermittent recovery test level 1: reliability and variability. J Strength Cond Res 33(3): 819-824, 2019-The Yo-Yo Intermittent Recovery Test Level 1 (YYIR1) has been shown to be a reliable test with strong correlations to physical match performance in field soccer players. However, the YYIR1 has less goalkeeper (GK) specificity. Therefore, the purpose of this study was to evaluate the test-retest reliability of a goalkeeper-specific adaptation of the YYIR1 (YYIR1-GK). Sixteen National Collegiate Athletic Association (NCAA) collegiate GKs (8 men and 8 women) performed the YYIR1-GK test twice (>4 and <7 days apart) to determine its reliability and variability. Subjects were tested at the same time of day and in a controlled indoor environment. Heart rate using polar monitors and rating of perceived exertion were obtained at the end of each stage of the YYIR1-GK. Test-retest reliability for each test was assessed by Pearson correlations, intraclass correlation coefficient (ICC), and coefficient of variation (CV). The YYIR1-GK was shown to have a strong test-retest reliability and low variability for male (r = 0.981, ICC = 0.980, CV = 5.82%) and female (r = 0.969, ICC = 0.956, CV = 9.60%) NCAA GKs, respectively. Male GKs performed significantly more stages and therein covered a greater distance in the YYIR1-GK than the female GKs (p = 0.05). This study suggests that the YYIR1-GK is a consistent assessment of intermittent fitness with high test-retest reliability and low variability in male and female NCAA GKs. It is suggested that larger numbers of GKs of various skill levels be evaluated in the future.

Quality of life as a mediator of leisure activity and perceived health among older women.

Despite consistent evidence to suggest that participating in leisure is associated with perceived health status among older adults, there have been few attempts to determine the possible underlying mechanisms in this relationship, including the role of quality of life (QoL). This study examined the role of perceived quality of life in the relationship between leisure and perceived health in older women. Correlations, regression, and mediation analysis were conducted on data from the Woman's College Alumnae Women's Health Study. Results indicate that QoL partially mediates the relationship between leisure and perceived health in older women. Findings further establish the link between leisure and perceived health with QoL playing an important role in the relationship.

The Physical Activity and Alzheimer's Disease (PAAD) Study: Cognitive outcomes.

Background: Alzheimer's disease is a progressive disease that degrades cognitive functioning and ultimately results in death. Currently, there is no cure for Alzheimer's disease and, hence, the identification of preventative strategies is important. Physical activity (PA) is a behavioral intervention that holds promise with respect to delaying the onset of Alzheimer's disease. Purpose: The purpose of this study was to explore the differential cognitive benefits achieved in response to PA as a function of a person's genetic risk for AD. Methods: Older cognitively normal adults (50-65 years) with a family history of AD (FHxAD) participated in an 8-month PA program. Cognitive performance was measured at baseline, pretest, midtest, and posttest and changes over time were assessed as a function of apolipoprotein E (APOE) status (carriers: 1-2 copies of the ɛ4 allele; noncarriers: 0 copies of the ɛ4 allele). Results: Improvements in memory were associated with PA participation irrespective of APOE ɛ4 carrier status. Conclusions: Future experimental studies are needed to confirm that PA causes improvements to cognitive performance in older cognitively normal adults with a FHxAD and that these improvements are equivalent for cognitively normal APOE ɛ4 carriers and noncarriers.