Moderate Vigorous Activity Research Articles

One Hour a Week: Moving to Prevent Disability in Adults With Lower Extremity Joint Symptoms

Physical activity guidelines recommend minimum thresholds. This study sought to identify evidence-based thresholds to maintain disability-free status over 4years among adults with lower extremity joint symptoms. Prospective multisite Osteoarthritis Initiative accelerometer monitoring cohort data from September 2008 through December 2014 were analyzed. Adults (n=1,564) aged ≥49years at elevated disability risk because of lower extremity joint symptoms were analyzed for biennial assessments of disability-free status from gait speed ≥1meter/second (mobility disability-free) and self-report of no limitations in activities of daily living (activities of daily living disability-free). Classification tree analyses conducted in 2017-2018 identified optimal thresholds across candidate activity intensities (sedentary, light, moderate-vigorous, total light and moderate-vigorous activity, and moderate-vigorous accrued in bouts lasting ≥10 minutes). Minimal thresholds of 56 and 55 moderate-vigorous minutes/week best predicted disability-free status over 4years from mobility and activities of daily living disabilities, respectively, across the candidate measures. Thresholds were consistent across sex, BMI, age, and knee osteoarthritis presence. Mobility disability onset was one eighth as frequent (3% vs 24%, RR=0.14, 95% CI=0.09, 0.20) and activities of daily living disability onset was almost half (12% vs 23%, RR=0.55, 95% CI=0.44, 0.70) among people above versus below the minimum threshold. Attaining an evidence-based threshold of approximately 1-hour moderate-vigorous activity/week significantly increased the likelihood of maintaining disability-free status over 4years. This minimum threshold tied to maintaining independent living abilities has value as an intermediate goal to motivate adults to take action towards the many health benefits of a physically active lifestyle.

Usefulness of a Positive Psychology-Motivational Interviewing Intervention to Promote Positive Affect and Physical Activity After an Acute Coronary Syndrome

Most patients are not able to achieve recommended levels of physical activity following an acute coronary syndrome (ACS). Existing interventions to promote activity have not focused on promoting psychological well-being, which is independently linked to superior cardiac health. To address this gap, we developed and tested a combined positive psychology-motivational interviewing (PP-MI) intervention in post-ACS patients to assess its feasibility and explore potential benefits in an initial randomized trial. We compared a 12-week, phone-delivered, PP-MI intervention to an attention-matched, MI-based health education control condition among 47 post-ACS patients with low baseline health behavior adherence. Feasibility/acceptability were assessed through rates of session completion and participant session ratings; we also explored between-group differences in positive affect, other self-reported outcomes, and accelerometer-measured physical activity, through mixed effects regression models, at 12 and 24 weeks. PP-MI participants completed a mean of 10.0 (standard deviation 2.2) sessions (84%), and mean participant ratings of sessions' ease/utility were >8/10, above a priori thresholds for success. Compared with the control condition, PP-MI was associated with greater improvements in positive affect at 12 and 24 weeks (12 weeks: estimated mean difference [EMD] = 3.90 [SE = 1.95], p = 0.045, effect size [ES] = 0.56; 24 weeks: EMD = 7.34 [SE = 2.16], p <0.001, ES = 1.12). PP-MI was also associated with more daily steps at 12 weeks (EMD = 1842.1 steps/day [SE = 849.8], p = 0.030, ES = 0.76) and greater moderate-vigorous activity at 24 weeks (EMD = 15.1 minutes/day [SE = 6.8], p = 0.026, ES = 0.81). In conclusion, PP-MI was feasible in post-ACS patients and showed promising effects on well-being and physical activity; additional studies are needed to confirm these findings.

Physical Activity and Worsening of Radiographic Findings in Persons With or at Higher Risk of Knee Osteoarthritis.

The benefits of physical activity among persons with or at higher risk for knee osteoarthritis are well established. However, activity levels in this population are low, in part due to concern that activity will damage the knee joint. We hypothesized that sedentary and moderate-vigorous physical activity are each associated with greater risk of radiographic worsening of knee OA. In Osteoarthritis Initiative participants with or at higher risk for knee OA enrolled in an accelerometer substudy at 48 months (study baseline), physical activity was measured by a uniaxial accelerometer (ActiGraph GT1M). Radiographic progression was defined as any 48 month to 96 month worsening of Kellgren/Lawrence (K/L) grade scores. All analyses were knee-level; we used multivariable logistic regression with generalized estimating equations, adjusting for key covariates. Of the 1,206 participants, 631 (52%) were female, the mean ± SD age was 64 ± 9 years, and mean ± SD body mass index (BMI) was 28 ± 5. The mean ± SD average daily sedentary activity was 602 ± 86 minutes, average daily light activity was 284 ± 75 minutes, and average daily moderate-vigorous activity was 20 ± 20 minutes. In 1,978 knees, 267 (14%) had worsening of K/L grade scores. In the multivariable model, age, sex, BMI, and pain, were associated with K/L grade worsening, but neither sedentary activity (adjusted odds ratio [OR] 0.99 [95% confidence interval (95% CI) 0.97-1.01]) nor moderate-vigorous activity (adjusted OR 1.00 [95% CI 0.91-1.09]) were associated with K/L grade worsening. In persons with or at higher risk for knee OA, age, sex, BMI, and pain, but not objectively measured average daily minutes of sedentary or moderate-vigorous activity, were associated with subsequent worsening of K/L grade. Whether findings differ in persons with more severe knee OA and/or engaged more frequently in moderate-vigorous activity should be examined in future studies.

The Association of the Body Composition of Children with 24-Hour Activity Composition

To evaluate how the reallocation of time between sleep, sedentary time, light, and moderate-vigorous activities is associated with children's body composition. Population-based cross-sectional Child Health CheckPoint within the Longitudinal Study of Australian Children (n=938 11-12 year-olds, 50% boys). Twenty-four hour activity composition via accelerometry (minutes/day of sleep, sedentary time, light, and moderate-to-vigorous physical activity [MVPA]) and 3-part body composition (percentage truncal fat, percentage nontruncal fat, and percentage fat-free mass) via bioelectrical impedance analysis were measured. We estimated differences in 3-part body composition associated with the incremental reallocation of time between activities, using dual-compositional regression models adjusted for sex, age, puberty, and socioeconomic position. Reallocation of time between MVPA and any other activity was strongly associated with differences in body composition. Adverse body composition differences were larger for a given MVPA decrease than were the beneficial differences for an equivalent MVPA increase. For example, 15minutes less MVPA (relative to remaining activities) was associated with absolute percentage differences of +1.7% (95% CI 1.2; 2.4) for truncal fat, +0.8% (0.6; 1.2) for nontruncal fat, and -2.6% (-3.5; -1.9) for fat-free mass, and a 15-minute increase was associated with -0.7% (-0.9; -0.5) truncal fat, -0.4% (-0.5; -0.3) nontruncal fat, and +1.1% (0.9; 1.5) fat-free mass. Reallocations between sleep, sedentary time, and light physical activity were not associated with differences in body composition. Preventing declines in MVPA during inactive periods (eg, holidays) may be an important intervention goal. More MVPA, instead of other activities, may benefit body composition.

Exercise Dose Effects on Body Fat 12 Months after an Exercise Intervention: Follow-up from a Randomized Controlled Trial.

Background Exercise interventions can result in weight loss, which is associated with reductions in disease risk. It is unknown how the volume of exercise prescribed in a one-time exercise intervention impacts long-term body fatness. We compared 24-month body fat changes among postmenopausal women previously prescribed 300 versus 150 minutes/week of exercise in a year-long exercise intervention trial. Methods The Breast Cancer and Exercise Trial in Alberta (BETA) was a two-centred randomized controlled trial in Alberta, Canada. The trial consisted of a 12-month intervention and 12-month observation period. For the intervention, participants were randomized to either a moderate-volume exercise group (150 min/week) or a high-volume exercise group (300 min/week). Participants in this study were 334 inactive postmenopausal women who had been followed-up to 24 months. The primary outcome for this study was 24-month change in total body fat using dual energy X-ray absorptiometry scans. Other measures included weight, waist and hip circumferences, subcutaneous and intra-abdominal fat from computed tomography scans, and lean mass. Researchers were blinded to randomization group when measuring body fat. Results Both groups self-reported ∼180 minutes/week moderate–vigorous activity at 24 months. No statistically significant difference was found in total body fat at 24 months between the two groups. Statistically significant effects (comparing high versus moderate groups) were found for BMI (least-square mean change (95% CI): −0.66 (−0.97, −0.36) versus −0.25 (−0.55, 0.05) kg/m2, P=0.04), waist-to-hip ratio (−0.033 (−0.040, −0.026) versus −0.023 (−0.030, −0.016), P=0.05), and subcutaneous abdominal fat area (−32.18 (−39.30, −25.06) versus −22.20 (−29.34, −15.05) cm2, P=0.04). Conclusion Prescribing 300 versus 150 minutes/week of exercise to inactive postmenopausal women resulted in some long-term greater decreases in measures of body composition but no overall differences in total body fat loss. This trail is registered with NCT01435005.

Use of Time and Energy on Exercise, Prolonged TV Viewing, and Work Days

The goal of this study was to describe differences in time use and energy expenditure associated with exercise, prolonged TV viewing, and work days in a longitudinal study of older adults. Participants were 1,020 adults who completed previous-day recalls that provided a profile of the use of time in sedentary and physical activity. Time use and physical activity energy expenditure were predicted for each type of day (exercise, prolonged TV, work) using linear mixed models, adjusting for age, sex, season of the year, and day of the week. Data were collected in 2012-2013; analysis was completed in 2017. Exercise days had less sedentary time (-0.37 hours/day) and light activity (-0.29 hours/day), and less household, work, and shopping activities, such that the increase in total physical activity energy expenditure on exercise days (2.83 MET-hours/day) was only about half that expended during exercise (5.98 MET-hours/day). Prolonged TV viewing days had more total sedentary time (0.86 hours/days) and less light (-0.45 hours/day) and moderate-vigorous intensity activity (-0.41 hours/day), and thus lower total physical activity energy expenditure (-2.43 MET-hours/day). Work days had less sleep (-0.91 hours/day) and more total sedentary time (1.32 hours/day). Exercise days had more physical activity energy expenditure, but because of reductions in other activities, only about half of the energy expended during exercise was added to total daily physical activity energy expenditure. Prolonged TV viewing days had less physical activity energy expenditure and less moderate-vigorous activity. These findings provide new insights into possible compensation associated with exercise, and suggest a strong link between TV viewing and physical inactivity.

Objective physical activity levels in people with multiple sclerosis: Meta-analysis.

To quantify physical activity (PA) levels in people with multiple sclerosis (pwMS) using objective measurement and to establish using a meta-analytical approach if pwMS are less active than the general population. A systematic search of eight databases was conducted. Cohort and intervention studies which included an objective measure of PA were included. Objective PA outputs of steps per day and minutes of moderate-vigorous activity (MVPA) per day were extracted from the MS studies and the published NHANES dataset. Meta-analysis was used to compare the differences between the groups for these parametric outcomes. A general population sample from the National Health and Nutritional Examination Survey (NHANES) in the United States of America was used as a comparative group. The systematic search resulted in 32 papers (n=2 randomized control trials, n=30 cohort studies). A total of 3 762 pwMS were included. The sample was largely female (n=3 118, 82.8%) and ambulatory with/without use of an aid (n=31 studies). There were significant differences between the MS and the published NHANES comparative group with respect to 1) steps per day [mean difference: -3845 (-4120.17, -3569.83), P<.0001, n=10 studies] and 2) minutes of MVPA per day [mean difference: 9.00 (-12.5, -5.4), P<.0001, n=3 studies], indicating pwMS are less physically active than the NHANES sample. Results suggest that pwMS are less physically active than a general population across PA outputs of steps per day and minutes of MVPA per day. There is a need to increase PA levels among pwMS.

Association Between Exercise And Prolonged Television Viewing Days On Time-use And Physical Activity Energy Expenditure In Older Us Adults

PURPOSE. Our goal was to estimate the time-use exchanges associated with exercise, prolonged television viewing, and work days on the amount and type of sedentary and physically active behaviors and physical activity energy expenditure. METHODS. Participants were 1,020 older adults who completed up to 6 detailed previous-day recalls over 12-months that provided a profile of the use of time in sedentary and physically active pursuits. We predicted time-use and physical activity energy expenditure (PAEE) outcomes for 1) days with and without exercise, 2) days with or without prolonged television (2+h/day), and 3) work vs non-work days. To estimate time-use exchanges we used repeated measures and linear mixed models, adjusting for age, sex, season of the year, and day of the week. RESULTS. Exercise days were associated with less sedentary time (-0.37 hrs/d) and light activity (-0.29 hrs/d), and less household, work, and shopping activities. Compared to non-exercise days, the increase in total PAEE on exercise days (2.83 MET-hrs/d) was only about half that expended during exercise (5.98 MET-hrs/d). Prolonged television viewing was associated with an increase in total sedentary time (0.86 hrs/d) and less light (-0.45 hrs/d) and moderate-vigorous intensity activity (-0.41 hrs/d), and thus lower total PAEE (-2.43 MET-hrs/d). Work days were associated with less sleep (-0.91 hrs/d) and an increase in total sedentary time (1.32 hrs/d). DISCUSSION. Exercise was associated with an increase in PAEE, but due to reductions in other activities, only about half of the energy expended during exercise trickled-up to total daily PAEE. Prolonged television viewing was associated less PAEE and less moderate- vigorous activity. These findings provide new insights into possible compensation associated with exercise training, and suggest a strong link between television viewing and physical inactivity.

Accelerometer-derived physical activity and sedentary time by cancer type in the United States.

The 2003–2004 and 2005–2006 cycles of the National Health and Nutrition Examination Survey (NHANES) were among the first population-level studies to incorporate objectively measured physical activity and sedentary behavior, allowing for greater understanding of these behaviors. However, there has yet to be a comprehensive examination of these data in cancer survivors, including short- and long-term survivors of all cancer types. Therefore, the purpose of this analysis was to use these data to describe activity behaviors in short- and long-term cancer survivors of various types. A secondary aim was to compare activity patterns of cancer survivors to that of the general population. Cancer survivors (n = 508) and age-matched individuals not diagnosed with cancer (n = 1,016) were identified from a subsample of adults with activity measured by accelerometer. Physical activity and sedentary behavior were summarized across cancer type and demographics; multivariate regression was used to evaluate differences between survivors and those not diagnosed with cancer. On average, cancer survivors were 61.4 (95% CI: 59.6, 63.2) years of age; 57% were female. Physical activity and sedentary behavior patterns varied by cancer diagnosis, demographic variables, and time since diagnosis. Survivors performed 307 min/day of light-intensity physical activity (95% CI: 295, 319), 16 min/day of moderate-vigorous intensity activity (95% CI: 14, 17); only 8% met physical activity recommendations. These individuals also reported 519 (CI: 506, 532) minutes of sedentary time, with 86 (CI: 84, 88) breaks in sedentary behavior per day. Compared to non-cancer survivors, after adjustment for potential confounders, survivors performed less light-intensity activity (P = 0.01), were more sedentary (P = 0.01), and took fewer breaks in sedentary time (P = 0.04), though there were no differences in any other activity variables. These results suggest that cancer survivors are insufficiently active. Relative to adults of similar age not diagnosed with cancer, they engage in more sedentary time with fewer breaks. As such, sedentary behavior and light-intensity activity may be important intervention targets, particularly for those for whom moderate-to-vigorous activity is not well accepted.

Fatigue and its relationship with physical activity in adolescents and young adults with traumatic brain injury: a cross-sectional study.

Physical activity (PA) in patients with traumatic brain injury (TBI) may be impaired leading to secondary health issues and limitations in participation. This study aims to determine the level of PA and its determinants in adolescents and young adults with TBI. Cross-sectional survey study. Outpatient clinic of a rehabilitation center. Discharged patients aged 12-39 years with a diagnosis of TBI >6 months treated in the rehabilitation center between 2009-2012. The Activity Questionnaire for Adults and Adolescents (AQuAA) measuring PA, with results dichotomized for meeting or not meeting Dutch recommendations for health-enhancing physical activity (D-HEPA) and the Checklist Individual Strength questionnaire (CIS; range 20-140, higher scores represent higher levels of fatigue), measuring fatigue, were administered. Fifty (47%) of the 107 invited patients completed the questionnaire. Mean age was 25.0±7.2 years and 22 (44%) were male. Eighteen (36%) had a mild injury, 13 (26%) a moderate injury and 19 (38%) a severe injury. Median time spent on moderate-vigorous physical activity was 518 minutes/week (IQR 236-1725) (males performing significantly more minutes on moderate-vigorous activity than women) and on sedentary activity 2728 minutes/week (IQR 1637-3994). Thirty-two (64%) participants met the D-HEPA. According to the CIS, 19 participants (38%) were severely fatigued. Both the CIS total score and the subscales motivation and physical activity were associated with meeting the D-HEPA. The proportion of individuals with TBI meeting D-HEPA was similar to the general population, with the PA level being associated with self-reported fatigue. Physical activity programs are continuously being developed to increase the percentage of individuals meeting public health recommendations for PA; when developing programs for individuals with TBI extra consideration should be taken for the presence of fatigue. As in the general population, females with TBI are less active, PA programs should probably consider gender differences in their development.

Moderate-vigorous recreational physical activity and breast cancer risk, stratified by menopause status: a systematic review and meta-analysis.

Physical inactivity increases postmenopausal and possibly premenopausal breast cancer risk, although different biologic mechanisms are proposed. Our primary objective was to estimate breast cancer risk associated with high versus low levels of moderate-vigorous recreational activity, separately for premenopausal and postmenopausal women. We conducted a systematic review of literature published to July 2015. Included reports were cohort or case-control studies relating moderate-vigorous recreational physical activity (metabolic equivalent ≥3.0) to breast cancer incidence, exclusively (≥90%) in premenopausal or postmenopausal women. We appraised study quality and performed meta-analyses using random effects modeling. Subgroup meta-analyses were based on tumor subtype, race, body mass index, parity, hormone therapy use, family history of cancer, and statistical adjustment for body fatness. Dose-response relations were examined. Pooled relative risks (RRs, 95% CI) for women with higher versus lower levels of moderate-vigorous recreational activity were RR = 0.80 (0.74-0.87) and RR = 0.79 (0.74-0.84) for premenopausal (43 studies) and postmenopausal (58 studies) breast cancer, respectively, with high heterogeneity. Inverse associations were weaker among postmenopausal cohort studies (RR = 0.90 [0.85-0.95]) and studies that statistically adjusted for nonrecreational (eg, occupational, household) activity (RR = 0.91 [0.77-1.06] premenopausal, RR = 0.96 [0.86-1.08] postmenopausal). Risk estimates with versus without body fatness adjustment did not vary by menopause status, although other subgroup effects were menopause-dependent. Among studies of overweight/obese women, there was an inverse association with postmenopausal but not premenopausal breast cancer (RR = 0.88 [0.82-0.95] and RR = 0.99 [0.98-1.00], respectively). Dose-response curves were generally nonlinear. Although risk estimates may be similar for premenopausal and postmenopausal breast cancer, subgroup effects may be menopause-dependent.

Physical Activity Minimum Threshold Predicting Improved Function in Adults With Lower-Extremity Symptoms.

To identify an evidence-based minimum physical activity threshold to predict improved or sustained high function for adults with lower-extremity joint symptoms. Prospective multisite data from 1,629 adults, age ≥49 years with symptomatic lower-extremity joint pain/aching/stiffness, participating in the Osteoarthritis Initiative accelerometer monitoring substudy were clinically assessed 2 years apart. Improved/high function in 2-year gait speed and patient-reported outcomes (PROs) were based on improving or remaining in the best (i.e., maintaining high) function quintile compared to baseline status. Optimal thresholds predicting improved/high function were investigated using classification trees for the legacy federal guideline metric requiring 150 minutes/week of moderate-vigorous (MV) activity in bouts lasting 10 minutes or more (MV-bout) and other metrics (total MV, sedentary, light intensity activity, nonsedentary minutes/week). Optimal thresholds based on total MV minutes/week predicted improved/high function outcomes more strongly than the legacy or other investigated metrics. Meeting the 45 total MV minutes/week threshold had increased relative risk (RR) for improved/high function (gait speed RR 1.8, 95% confidence interval [95% CI] 1.6, 2.1 and PRO physical function RR 1.4, 95% CI 1.3, 1.6) compared to less active adults. Thresholds were consistent across sex, body mass index, knee osteoarthritis status, and age. These results supported a physical activity minimum threshold of 45 total MV minutes/week to promote improved or sustained high function for adults with lower-extremity joint symptoms. This evidence-based threshold is less rigorous than federal guidelines (≥150 MV-bout minutes/week) and provides an intermediate goal towards the federal guideline for adults with lower-extremity symptoms.

Measuring Physical Activity with Hip Accelerometry among U.S. Older Adults: How Many Days Are Enough?

IntroductionAccelerometers are increasingly used in research. Four to 7 days of monitoring is preferred to estimate average activity but may be burdensome for older adults. We aimed to investigate: 1) 7-day accelerometry protocol adherence, 2) demographic predictors of adherence, 3) day of the week effect, and 4) average activity calculated from 7 versus fewer days among older adults.MethodsWe used the 2003–2006 older adult hip accelerometry data from the National Health and Nutrition Examination Survey (NHANES) sample. We determined proportions with 1–7 valid (10–20 hours) wear days and identified wear day correlates using ordinal logistic regression. We determined the day of week effect on 5 accelerometry measures (counts per minute, CPM; % sedentary behavior; % light-lifestyle activity; % moderate-vigorous activity, MVPA; total activity counts) using multivariate linear regression and compared averages estimated over 2 or 3 versus 7 days using correlations, linear regression, and Bland-Altman plots.ResultsAmong 2,208 participants aged 65+, 85% of participants had ≥2 and 44% had 7 valid wear days. Increasing age (p = 0.01) and non-white race (p < 0.001) were associated with fewer days. Daily CPM, % MVPA, and total daily activity counts were similar Monday through Saturday, but significantly lower on Sundays (p < 0.001). Daily % sedentary behavior and % light-lifestyle activity were significantly different on Saturdays (p = 0.04–0.045) and Sundays (p < 0.001) compared to weekdays. Among participants with 7 valid days, 2 or 3 day averages were highly correlated with 7 day averages for all 5 accelerometry measures (2 versus 7 days: r = 0.90–0.93, 3 versus 7 days: r = 0.94–0.96).ConclusionsProtocols of 2–3 days, adjusting for Sundays (average CPM, % moderate-vigorous activity, and average total daily activity counts) or weekends (% sedentary behavior and % light-lifestyle activity), give reliable estimates of older adult activity.

Physical activity, black carbon exposure and airway inflammation in an urban adolescent cohort

ObjectiveRegular physical activity can improve cardiopulmonary health; however, increased respiratory rates and tidal volumes during activity may increase the effective internal dose of air pollution exposure. Our objective was to investigate the impact of black carbon (BC) measured by personal sampler on the relationship between physical activity and fractional exhaled nitric oxide (FeNO), a marker of airway inflammation. We hypothesized that higher personal BC would attenuate the protective effect of physical activity on airway inflammation. MethodsWe performed a cross-sectional study nested in a birth cohort of African American and Dominican children living in the Bronx and Northern Manhattan, New York City. Children were recruited based on age (target 9–14 year olds) and presence (n=70) or absence (n=59) of current asthma. Children wore wrist mounted accelerometers for 6 days and were classified as ‘active’ if they had ≥60min of moderate-to-vigorous activity (MVA) each day and ‘non-active’ if they had <60min of MVA on any given day, based on CDC guidelines. Personal BC measured using a MicroAeth, was assessed during two 24-h periods, at the beginning and end of physical activity assessment. High BC was defined as the upper tertile of BC measured with personal sampler. FeNO measurements were sampled at the beginning and end of the of physical activity assessment. ResultsIn multivariable linear regression models, ‘active’ children had 25% higher personal BC concentrations (p=0.02) and 20% lower FeNO (p=0.04) compared to ‘non-active’ children. Among children with high personal BC (n=33), there was no relationship between activity and FeNO (p=1.00). The significant protective relationship between activity and airway inflammation was largely driven by children with lower personal BC (n=96, p=0.04). ConclusionsChildren that live in an urban environment and are physically active on a daily basis have higher personal exposure to BC. High BC offsets the protective relationship between physical activity and airway inflammation.

The gap between clinically assessed physical performance and objective physical activity in liver transplant candidates.

Frailty with sarcopenia in cirrhosis causes liver transplant wait-list attrition and deaths. Regular physical activity is needed to protect patients with cirrhosis from frailty. We subjectively assess physical performance in selecting patients for transplant listing, but we do not know whether clinical assessments reflect the extent of activity patients actually perform. To investigate this question, 53 wait-listed patients self-assessed their performance of ordinary physical tasks using the Rosow-Breslau survey, and clinicians assessed their physical performance status with the Karnofsky index. We compared these assessments with actual activity measured using an accelerometer/thermal sensing armband worn from 4 to 7 days. We found that their measured activity was among the lowest reported in chronic disease, similar to that of patients with advanced chronic pulmonary disease or renal failure. Their percentages of waking hours spent in sedentary, light, and moderate-vigorous activity were 75.9% ± 18.9%, 18.9% ± 14.3%, and 4.9% ± 6.9%, respectively. Higher mean sedentary and lower mean moderate-vigorous activity was significantly associated with 9 wait-list deaths (P = 0.004). Compared with a range of 7000-13,000 steps/day in healthy adults, patients' mean steps/day were 3164 ± 2842. Both their activity percentage and step data were typical of other severely inactive populations. Neither their Rosow-Breslau scores (mean 2.3 ± 0.8, maximum 3.0) nor their Karnofsky scores (mean 79 ± 12, maximum 100) suggested major impairment or showed a correlation with patients' actual physical performance. In conclusion, physical activity in patients with cirrhosis wait-listed for transplantation is highly sedentary. Self-assessments and provider assessments of physical activity do not reliably indicate actual performance. Whether the gap between assessed and actual performance may be favorably modified by interventions to improve activity and ameliorate frailty merits further study. Liver Transplantation 22 1324-1332 2016 AASLD.

Physical activity, sleep quality, and self-reported fatigue across the adult lifespan

Deteriorating sleep quality and increased fatigue are common complaints of old age, and poor sleep is associated with decreased quality of life and increased mortality rates. To date, little attention has been given to the potential effects of physical activity on sleep quality and fatigue in aging. The purpose of this study was to examine the relationships between activity, sleep and fatigue across the adult lifespan. Sixty community-dwelling adults were studied; 22 younger (21–29years), 16 middle-aged (36–64years), and 22 older (65–81years). Physical activity was measured by accelerometer. Sleep quality was assessed using the Pittsburg Sleep Quality Index. Self-reported fatigue was evaluated with the Patient-Reported Outcomes Measurement Information System (PROMIS). Regression analysis revealed a positive relationship between activity and sleep quality in the older (r2=0.18, p=0.05), but not the younger (r2=0.041, p=0.35) or middle-aged (r2=0.001, p=0.93) groups. This association was mainly established by the relationship between moderate-vigorous activity and sleep quality (r2=0.37, p=0.003) in older adults. No association was observed between physical activity and self-reported fatigue in any of the groups (r2≤0.14, p≥0.15). However, an inverse relationship was found between sleep quality and fatigue in the older (r2=0.29, p=0.05), but not the younger or middle-aged (r2≤0.13, p≥0.10) groups. These results support the hypothesis that physical activity may be associated with sleep quality in older adults, and suggest that improved sleep may mitigate self-reported fatigue in older adults in a manner that is independent of activity.

Physical activity, sedentary behavior, and vitamin D metabolites

Physical activity is associated with circulating 25-hydroxyvitamin D (25(OH)D). However, the influence of activity and/or sedentary behavior on the biologically active, seco-steroid hormone 1α,25-dihydroxyvitamin D (1,25(OH)2D) is unknown. We conducted a cross-sectional analysis among ursodeoxycholic acid (UDCA) randomized trial participants (n=876) to evaluate associations between physical activity, sedentary behavior, and circulating vitamin D metabolite concentrations. Continuous vitamin D metabolite measurements and clinical thresholds were evaluated using multiple linear and logistic regression models, mutually adjusted for either 1,25(OH)2D or 25(OH)D and additional confounding factors. A statistically significant linear association between 1,25(OH)2D and moderate-vigorous physical activity per week was strongest among women (β (95% CI): 3.10 (1.51–6.35)) versus men (β (95% CI): 1.35 (0.79–2.29)) in the highest tertile of activity compared to the lowest (p-interaction=0.003). Furthermore, 25(OH)D was 1.54ng/ml (95% CI 1.09-1.98) higher per hour increase in moderate-vigorous activity (p=0.001) and odds of sufficient 25(OH)D status was higher among physically active participants (p=0.001). Sedentary behavior was not significantly associated with either metabolite in linear regression models, nor was a statistically significant interaction by sex identified. The current study identified novel associations between physical activity and serum 1,25(OH)2D levels, adjusted for 25(OH)D concentrations. These results identify the biologically active form of vitamin D as a potential physiologic mechanism related to observed population-level associations between moderate-vigorous physical activity with bone health and chronic disease risk. However, future longitudinal studies are needed to further evaluate the role of physical activity and vitamin D metabolites in chronic disease prevention.

Abstract 19576: Impaired Fitness is Common in Adults Living With HIV, Despite Viral Suppression, and Correlates With Markers of Immune Dysregulation

Introduction: Since transitioning to a chronic health condition, treated HIV infection is now recognized as an independent risk factor for cardiovascular disease. The underlying reasons for this risk association are unclear, but may include poor cardiopulmonary fitness. Objective: To describe cardiopulmonary fitness in people living with HIV (PLHIV) and its association to lifestyle exercise and HIV characteristics. Methods: As part of a larger randomized clinical trial, we conducted a cross sectional analysis of 37 PLHIV at high risk for developing CVD, on HIV medications, with suppressed HIV viremia. All subjects completed a bicycle cardiopulmonary stress test using a ramp protocol, wore an accelerometer on their hip for seven days, and consented to medical chart abstraction. We summarize the exercise habits and baseline cardiopulmonary fitness of our population, and further analyzed associations between continuous variables using Spearman correlation coefficients. Results: Overall, the study population had poor cardiopulmonary fitness (Table 1). Subjects exercised on average twice in the past week, but mostly (85%) light activity. Current CD4+ T cell count was significantly associated with VO2 max, peak heart rate, and % peak heart rate (Table 2). As expected, fitness variables were also associated in a graded fashion with time spent exercising in light, moderate, and moderate-vigorous activity. Conclusions: Current CD4+ T cell count and lifestyle exercise are significantly and consistently associated with cardiopulmonary fitness. Further work is necessary to understand how these relationships change over time and in response to interventions.

Fatigue May Contribute to Reduced Physical Activity Among Older People: An Observational Study.

Fatigue is one of the most commonly reported symptoms in primary care and perceived by older people as an overwhelming and distressing experience that restricts their activity and social participation. Self-reported fatigue is complex and multifactorial, with relatively little known about the causes and impacts among older people. This study tested the association between fatigue and objectively measured physical activity in a large cohort of older adults and identified factors that may explain this association. Using cross-sectional data from 980 community-living 70- to 77-year-olds, the associations between self-reported fatigue and four physical activity outcomes derived from an accelerometer-based activity monitor were tested. Attenuating effects on the association of age, gender, body mass index (BMI), physical condition, comorbidity, depression, and sleep quality were evaluated. Nine percent of the sample reported being fatigued. Fatigued individuals had 1,150 fewer steps/day, 9 minutes/day less of moderate-vigorous activity, 12 minutes/day less of daily activity, and 15% fewer counts/minute, when compared with those not fatigued. BMI, physical condition, and comorbidity attenuated the association, and final regression models including these variables explained most (56%-72%) of the association between fatigue and activity. Fatigue was associated with clinically important reductions in daily physical activity levels of older people. The findings show BMI, physical condition (in particular cardiorespiratory fitness), and comorbidity to be important factors in explaining the fatigue-physical activity association. Modification of these factors may facilitate increases in daily activity levels by lessening fatigue.

Food, Health & Choices (FHC): How Perceptions of Maternal and Peer Energy Balance Behaviors Relate to Students’ Own Behaviors

Many health behavior theories implement social determinants, yet exactly how social factors influence energy balance-related behaviors (EBRBs) remains unclear. This study examines how children’s perceptions of others’ EBRBs compare to their own. Fifth grade students (n=215; 10.8y; 49.8% male) in four urban public schools participated in the delayed control FHC childhood obesity prevention curriculum and wellness policy intervention during the 2013-14 school year. Students completed an audience response system questionnaire pre- and post-intervention which measured their EBRBs and those perceived of their peers and mothers. General linear models were constructed (SPSS v20) to examine how children’s post-behaviors were explained by mothers’ and peers’ pre-behaviors, controlling for children’s own pre-behaviors and gender. Students’ higher perceptions of mothers’ vegetable intake was related to increased vegetable frequency post intervention (F=4.586, P=0.034). Also, perceptions of lower sweetened beverage intake by mothers resulted in lower post intervention intake of sweetened beverage (F=5.980, P=0.016). Similarly, positive perceptions of mothers’ behaviors led to longer bouts of moderate-vigorous activity (F=6.122, P=0.014) and less recreational screen time (F=8.689, P=0.004). Peers positively influenced fast food intake only (F=4.141, P=0.044). Children’s perceptions of mothers’ behaviors seemed to strongly influence both positive and negative EBRBs; those who were influenced by their mothers’ behaviors experienced an amplified effect of the FHC intervention. Upper elementary school children, while likely experiencing increased effects of peer pressure, still seem to be heavily influenced by perceptions of mothers’ EBRBs. Highlighting maternal influences is warranted in future obesity prevention studies.