Matthew P. Buman

Objective Light-Intensity Physical Activity Associations With Rated Health in Older Adults

The extent to which light-intensity physical activity contributes to health in older adults is not well known. The authors examined associations between physical activity across the intensity spectrum (sedentary to vigorous) and health and well-being variables in older adults. Two 7-day assessments of accelerometry from 2005 to 2007 were collected 6 months apart in the observational Senior Neighborhood Quality of Life Study of adults aged >65 years in Baltimore, Maryland, and Seattle, Washington. Self-reported health and psychosocial variables (e.g., lower-extremity function, body weight, rated stress) were also collected. Physical activity based on existing accelerometer thresholds for moderate/vigorous, high-light, low-light, and sedentary categories were examined as correlates of physical health and psychosocial well-being in mixed-effects regression models. Participants (N = 862) were 75.4 (standard deviation, 6.8) years of age, 56% female, 71% white, and 58% overweight/obese. After adjustment for study covariates and time spent in moderate/vigorous physical activity and sedentary behavior, low-light and high-light physical activity were positively related to physical health (all P < 0.0001) and well-being (all P < 0.001). Additionally, replacing 30 minutes/day of sedentary time with equal amounts of low-light or high-light physical activity was associated with better physical health (all P < 0.0001). Objectively measured light-intensity physical activity is associated with physical health and well-being variables in older adults.

Reallocating Time to Sleep, Sedentary Behaviors, or Active Behaviors: Associations With Cardiovascular Disease Risk Biomarkers, NHANES 2005–2006

Sleep and sedentary and active behaviors are linked to cardiovascular disease risk biomarkers, and across a 24-hour day, increasing time in 1 behavior requires decreasing time in another. We explored associations of reallocating time to sleep, sedentary behavior, or active behaviors with biomarkers. Data (n = 2,185 full sample; n = 923 fasting subanalyses) from the cross-sectional 2005-2006 US National Health and Nutrition Examination Survey were analyzed. The amounts of time spent in sedentary behavior, light-intensity activity, and moderate-to-vigorous physical activity (MVPA) were derived from ActiGraph accelerometry (ActiGraph LLC, Pensacola, Florida), and respondents reported their sleep duration. Isotemporal substitution modeling indicated that, independent of potential confounders and time spent in other activities, beneficial associations (P < 0.05) with cardiovascular disease risk biomarkers were associated with the reallocation of 30 minutes/day of sedentary time with equal time of either sleep (2.2% lower insulin and 2.0% lower homeostasis model assessment of β-cell function), light-intensity activity (1.9% lower triglycerides, 2.4% lower insulin, and 2.2% lower homeostasis model assessment of β-cell function), or MVPA (2.4% smaller waist circumference, 4.4% higher high-density lipoprotein cholesterol, 8.5% lower triglycerides, 1.7% lower glucose, 10.7% lower insulin, and 9.7% higher homeostasis model assessment of insulin sensitivity. These findings provide evidence that MVPA may be the most potent health-enhancing, time-dependent behavior, with additional benefit conferred from light-intensity activities and sleep duration when reallocated from sedentary time.

Mind the theoretical gap: interpreting, using, and developing behavioral theory in HCI research

Researchers in HCI and behavioral science are increasingly exploring the use of technology to support behavior change in domains such as health and sustainability. This work, however, remain largely siloed within the two communities. We begin to address this silo problem by attempting to build a bridge between the two disciplines at the level of behavioral theory. Specifically, we define core theoretical terms to create shared understanding about what theory is, discuss ways in which behavioral theory can be used to inform research on behavior change technologies, identify shortcomings in current behavioral theories, and outline ways in which HCI researchers can not only interpret and utilize behavioral science theories but also contribute to improving them.

The current state of physical activity assessment tools.

Physical activity (PA) is a behavior that involves bodily movements resulting in energy expenditure. When assessing PA, the goal is to identify the frequency, duration, intensity, and types of behaviors performed during a period of time. Self-report measures of PA include administration of questionnaires and completion of detailed diaries and/or brief logs. Direct measures include motion sensors such as accelerometers, pedometers, heart-rate monitors, and multiple-sensor devices. The PA assessment period can range from a few hours to a lifetime depending on the tools used. Considerations when selecting a PA tool should include the literacy requirements of a tool, the purpose for assessing PA, the recall or time period to measure, the validity evidence of an assessment tool for the populations measured, and the generalizability of the results to diverse populations.

Twenty-four Hours of Sleep, Sedentary Behavior, and Physical Activity with Nine Wearable Devices.

UNLABELLED Getting enough sleep, exercising, and limiting sedentary activities can greatly contribute to disease prevention and overall health and longevity. Measuring the full 24-h activity cycle-sleep, sedentary behavior (SED), light-intensity physical activity (LPA), and moderate-to-vigorous physical activity (MVPA)-may now be feasible using small wearable devices. PURPOSE This study compared nine devices for accuracy in a 24-h activity measurement. METHODS Adults (n = 40, 47% male) wore nine devices for 24 h: ActiGraph GT3X+, activPAL, Fitbit One, GENEactiv, Jawbone Up, LUMOback, Nike Fuelband, Omron pedometer, and Z-Machine. Comparisons (with standards) were made for total sleep time (Z-machine), time spent in SED (activPAL), LPA (GT3X+), MVPA (GT3X+), and steps (Omron). Analysis included mean absolute percent error, equivalence testing, and Bland-Altman plots. RESULTS Error rates ranged from 8.1% to 16.9% for sleep, 9.5% to 65.8% for SED, 19.7% to 28.0% for LPA, 51.8% to 92% for MVPA, and 14.1% to 29.9% for steps. Equivalence testing indicated that only two comparisons were significantly equivalent to standards: the LUMOback for SED and the GT3X+ for sleep. Bland-Altman plots indicated GT3X+ had the closest measurement for sleep, LUMOback for SED, GENEactiv for LPA, Fitbit for MVPA, and GT3X+ for steps. CONCLUSIONS Currently, no device accurately captures activity data across the entire 24-h day, but the future of activity measurement should aim for accurate 24-h measurement as a goal. Researchers should continue to select measurement devices on the basis of their primary outcomes of interest.

Exercise as a Treatment to Enhance Sleep

The prevalence of sleep-related complaints and the limited efficacy of pharmacological treatments make nonpharmacological alternatives essential. Physical exercise is one such alternative that is inexpensive and affects numerous health systems simultaneously. This article reviews putative mechanisms that have guided exercise and sleep research, including exercise’s antidepressant effects, restorative functions, and circadian effects, and concludes that a number of mechanisms are plausible and likely active in explaining the effects of exercise on sleep. The empirical literature is reviewed, with special emphasis given to randomized controlled trials and experimental studies that help to inform for whom (eg, age, fitness characteristics), under what conditions (eg, light exposure, time of day), and by what means (eg, type, intensity, duration) exercise optimally affects sleep. The review also includes the emerging research using exercise as a treatment of obstructive sleep apnea and restless legs syndrome. The current literature indicates that moderate amounts of exercise, which can be obtained through a variety of means such as brisk walking and resistance training, are sufficient to improve sleep quality. Additional research is warranted in this area, particularly randomized controlled trials that target subgroups at risk for poor sleep such as older adults and persons with sleep disorders.

Depression, Parenting Attributes, and Social Support among Adolescent Mothers Attending a Teen Tot Program

OBJECTIVE To investigate the associations between depressive symptoms in adolescent mothers and their perceived maternal caretaking ability and social support. PATIENTS AND METHODS Subjects were participants enrolled in a parenting program that provided comprehensive multidisciplinary medical care to teen mothers and their children. Baseline data of a prospective cohort study were collected by interview at 2 weeks postpartum and follow-up, and standardized measures on entry into postnatal parenting groups. Demographic data included education, social supports, psychological history, family history and adverse life events. Depressive symptoms were measured with the Center for Epidemiological Studies Depression Scale for Children short version (CES-DC). The Maternal Self-report Inventory (MSRI) measured perceived maternal self-esteem, and Duke-UNC Functional Social Support Questionnaire measured social support. Data were analyzed with bivariate analyses and linear regression modeling focusing on depressive symptoms as the outcome variable. RESULTS In the 168 teen mothers, mean age 17.6 +/- 1.2 years, African American (50%), Latina (31%) or Biracial (13%), the prevalence of depressive symptoms was 53.6%. In the linear model, controlling for babys age, teens age, ethnicity, Temporary Aid for Families with Dependent Children (TAFDC), and previous suicidal gesture, increased depressive symptoms were associated with decreased perceived maternal caretaking ability (P = 0.003) and lower social support (P < 0.001). In a linear model controlling for the same variables, MSRI total score (P = 0.001) and social support (P < 0.001) contributed significantly to the model as did the interaction term (MSRI x Social Support, P = 0.044). CONCLUSIONS Depression is associated with decreased maternal confidence in their ability to parent and decreased perceived maternal social support, with a possible moderating effect of social support on the relationship of maternal self-esteem and depression.

Peer volunteers improve long-term maintenance of physical activity with older adults: a randomized controlled trial.

BACKGROUND Using peer volunteers as delivery agents may improve translation of evidence-based physical activity promotion programs for older adults. This study examined whether tailored support from older peer volunteers could improve initiation and long-term maintenance of physical activity behavior. METHODS Participants were randomized to 2 16-week, group-based programs: (1) peer-delivered, theory-based support for physical activity behavior change; or (2) an intervention typically available in community settings (basic education, gym membership, and pedometer for self-monitoring), attention-matched with health education. Moderate-to-vigorous physical activity (MVPA) was assessed via daily self-report logs at baseline, at the end of the intervention (16 weeks), and at follow-up (18 months), with accelerometry validation (RT3) in a random subsample. RESULTS Seven peer volunteers and 81 sedentary adults were recruited. Retention at the end of the trial was 85% and follow-up at 18 months was 61%. Using intent-to-treat analyses, at 16 weeks, both groups had similar significant improvements in MVPA. At 18 months, the group supplemented with peer support had significantly more MVPA. CONCLUSIONS Trained peer volunteers may enhance long-term maintenance of physical activity gains from a community-based intervention. This approach has great potential to be adapted and delivered inexpensively in community settings.

Direct comparison of two actigraphy devices with polysomnographically recorded naps in healthy young adults.

The last 20 yrs have seen a marked increase in studies utilizing actigraphy in free-living environments. The aim of the present study is to directly compare two commercially available actigraph devices with concurrent polysomnography (PSG) during a daytime nap in healthy young adults. Thirty healthy young adults, ages 18–31 (mean 20.77 yrs, SD 3.14 yrs) simultaneously wore AW-64 and GT3X+ devices during a polysomnographically recorded nap. Mann-Whitney U (M-U) test, intraclass correlation coefficients, and Bland-Altman statistic were used to compare total sleep time (TST), sleep onset latency (SOL), wake after sleep onset (WASO), and sleep efficiency (SE) between the two actigraphs and PSG. Epoch-by-epoch (EBE) agreement was calculated to determine accuracy, sensitivity, specificity, predictive values for sleep (PVS) and wake (PVW), and kappa and prevalence- and bias-adjusted kappa (PABAK) coefficients. All frequency settings provided by the devices were examined. For both actigraphs, EBE analysis found accuracy, sensitivity, specificity, PVS, and PVW comparable to previous reports of other similar devices. Kappa and PABAK coefficients showed moderate to high agreement with PSG depending on device settings. The GT3X+ overestimated TST and SE, and underestimated SOL and WASO, whereas no significant difference was found between AW-64 and PSG. However, GT3X+ showed overall better EBE agreements to PSG than AW-64. We conclude that both actigraphs are valid and reliable devices for detecting sleep/wake diurnal patterns. The choice between devices should be based on several parameters as reliability, cost of the device, scoring algorithm, target population, experimental condition, and aims of the study (e.g., sleep and/or physical activity). (Author correspondence: smednick@ucr.edu)

Physical Activity Program Delivery by Professionals versus Volunteers: the TEAM Randomized Trial

OBJECTIVE Older adults have low rates of physical activity participation, but respond positively to telephone-mediated support programs. Programs are often limited by reliance on professional staff. This study tested telephone-based physical activity advice delivered by professional staff versus trained volunteer peer mentors. DESIGN A 12-month, randomized, controlled clinical trial was executed from 2003-2008. Twelve volunteer peer mentors and 181 initially inactive adults ages 50 years and older were recruited from the San Francisco Bay Area. Participants were randomized to: (1) telephone-based physical activity advice delivered by professional staff, (2) telephone-based physical activity advice delivered by trained volunteer peers, or (3) an attention-control arm of staff-delivered telephone support for nutrition. MAIN OUTCOME MEASURES Moderate-intensity or more vigorous physical activity (MVPA) was assessed at baseline, 6, and 12 months with the Community Healthy Activities Model Program for Seniors (CHAMPS) Questionnaire, with accelerometry validation (Actigraph) in a randomly selected subsample. Treatment fidelity was examined through analysis of quantity and quality of intervention delivery. RESULTS At 6 and 12 months, both physical activity arms significantly increased MVPA relative to the control arm. Both physical activity arms were comparable in quantity of intervention delivery, but peers demonstrated more versatility and comprehensiveness in quality of intervention content. CONCLUSIONS This study demonstrates that trained peer volunteers can effectively promote physical activity increases through telephone-based advice. The results support a program delivery model with good dissemination potential for a variety of community settings.