Best Practices for Meta-Reviews in Physical Activity and Health Research: Insights From the Physical Activity Guidelines for Americans Advisory Committee Scientific Report.

BACKGROUND: Systematic reviews (SRs) and meta-analyses (MAs) have proliferated with a concomitant increase in reviews of SRs/MAs or "meta-reviews" (MRs). As uncovered by the 2018 US Physical Activity Guidelines Advisory Committee (PAGAC), there is a paucity of best practice guidance on MRs on physical activity health-related research. This manuscript aims to fill this gap. METHODS: In total, the PAGAC conducted 38 literature searches across 3 electronic databases and triaged 20,838 titles, 4913 abstracts, and 2139 full texts from which 1130 articles qualified for the PAGAC Scientific Report. RESULTS: During the MR process, the following challenges were encountered: (1) if the SR/MA authors had limited experience in synthesis methodology, they likely did not account for risk of bias in the conclusions they reached; (2) many SRs/MAs reviewed the same primary-level studies; (3) many SRs/MAs failed to disclose effect modifier analyses; (4) source populations varied; (5) physical activity exposures were nonstandardized; and (6) dose-response effects or effect modification of the physical activity exposure could not be identified. CONCLUSIONS: Using examples from the PAGAC Scientific Report, we provide (1) a high-level introduction to MRs; (2) recommended steps in conducting a MR; (3) challenges that can be encountered; and (4) guidance in addressing these challenges.

Individualized Relative-Intensity Physical Activity Accelerometer Cut Points.

PURPOSE: Physical activity (PA) intensity is expressed as either absolute or relative intensity. Absolute intensity refers to the energy required to perform an activity. Relative intensity refers to a level of effort that takes into account how hard an individual is working relative to their maximum capacity. We sought to develop methods for obtaining individualized relative-intensity accelerometer cut points using data from a maximal graded exercise treadmill test (GXT) so that each individual has their own cut point. METHODS: A total of 2363 men and women 38 to 50 yr old from the CARDIA fitness study wore ActiGraph 7164 accelerometers during a maximal GXT and for seven consecutive days in 2005-2006. Using mixed-effects regression models, we regressed accelerometer counts on heart rate as a percentage of maximum (%HRmax) and on RPE. Based on these two models, we obtained a moderate-intensity (%HRmax = 64% or RPE = 12) count cut point that is specific to each participant. We applied these subject-specific cut points to the available CARDIA accelerometer data. RESULTS: Using RPE, the mean moderate-intensity accelerometer cut point was 4004 (SD = 1120) counts per minute. On average, cut points were higher for men (4189 counts per minute) versus women (3865 counts per minute) and were higher for Whites (4088 counts per minute) versus African Americans (3896 counts per minute). Cut points were correlated with body mass index (rho = -0.11) and GXT duration (rho = 0.33). Mean daily minutes of absolute- and relative-intensity moderate to vigorous PA were 34.1 (SD = 31.1) min·d and 9.1 (SD = 18.2) min·d, respectively. RPE cut points were higher than those based on %HRmax. This is likely due to some participants ending the GXT before achieving their HRmax. CONCLUSIONS: Accelerometer-based relative-intensity PA may be a useful measure of intensity relative to maximal capacity.

Direct and indirect effects of exercise on posttraumatic stress disorder symptoms: A longitudinal study.

OBJECTIVE: Emerging evidence suggests that exercise may have beneficial effects on posttraumatic stress disorder (PTSD), and that this relationship may be indirectly affected by sleep, pain, and alcohol/substance use. The present study examined the longitudinal direct and indirect effects of exercise on PTSD symptoms. METHOD: A national sample of 182 individuals, screening positive for PTSD, completed online assessments of PTSD symptoms, exercise behavior, psychological distress, sleep quality, and alcohol/substance use at baseline and three-month follow-up. RESULTS: There were direct effects of strenuous intensity exercise on avoidance/numbing (b=-2.18, SE=1.12, p=0.05) and hyperarousal symptoms (b=-1.87, SE=0.82, p=0.03); and direct effects of total exercise on avoidance/numbing symptoms (b=-1.76, SE=0.94, p=0.05). Strenuous intensity exercise was indirectly associated with total PTSD symptoms (ab=-2.53, 95% CI: -5.72 to -0.38), avoidance/numbing (ab=-0.99, 95% CI: -2.43 to -0.05), and hyperarousal symptoms (ab=-0.78, 95% CI: -1.88 to -0.07) through sleep, while total exercise was indirectly associated with total PTSD symptoms through alcohol use (ab=0.32, 95% CI: 0.18-1.42). CONCLUSION: Findings suggest that exercise has a complex, longitudinal, and beneficial association with PTSD symptoms. Future studies should continue to examine this relationship and any direct and indirect effects exercise may have on PTSD and its related conditions.

The Effect of Changes in Physical Activity on Sedentary Behavior: Results From a Randomized Lifestyle Intervention Trial.

PURPOSE: To investigate whether changes in physical activity (PA) have an impact on sedentary behavior (SB) during a lifestyle intervention. DESIGN: Study design was a randomized trial. SETTING/SUBJECTS: Participants (n = 204) were individuals with low PA and high sedentary leisure screen time from the Chicago area. INTERVENTION: Participants were randomized to either increase PA (iPA) or decrease sedentary leisure (dSED). The intervention consisted of decision support, coaching, and financial incentives. For iPA participants, the goal was at least 60 min/d of self-reported moderate-tovigorous-intensity PA (MVPA). For dSED participants the goal was less than 90 min/d of sedentary leisure screen time. MEASURES: Daily accelerometer-based measures of SB and bout-corrected MVPA were obtained. ANALYSIS: Linear mixed-effects models were fit to estimate the effect of the intervention on MVPA and total SB and to estimate the effect of daily changes in MVPA on daily SB. RESULTS: The iPA participants increased their bout-corrected MVPA by 14 min/d (p < .001) and decreased their total SB by 18 min/d (p < .001). The dSED participants did not significantly change their PA or their total SB. On days when participants exercised, each 10-minute bout of MVPA was associated with a 6-minute decrease in SB on the same day (p < .001). CONCLUSION: In an intervention study designed to increase MVPA, participants who increase their time spent exercising will obtain much of this time by reducing their SB.

Increasing US health plan coverage for exercise programming in community mental health settings for people with serious mental illness: a position statement from the Society of Behavior Medicine and the American College of Sports Medicine.

Adults with serious mental illness die more than 10 years earlier than the average American. Premature mortality is due to the high prevalence of preventable diseases including cardiovascular disease and diabetes. Poor lifestyle behaviors including lack of exercise and physical inactivity contribute to the epidemic levels of obesity, diabetes, and cardiovascular disease observed among adults with serious mental illness. Not surprisingly, people with serious mental illness are among the most costly consumers of health services due to increased visits for poorly managed mental and physical health. Recent studies have demonstrated that exercise interventions based on community mental health settings can significantly improve physical and mental health in people with serious mental illness. However, current funding regulations limit the ability of community mental health settings to offer exercise programming services to people with serious mental illness. Policy efforts are needed to improve the dissemination and sustainability of exercise programs for people with serious mental illness.

Integrating Physical Activity in Primary Care Practice.

Based on a collaborative symposium in 2014 hosted by the Society of Behavioral Medicine (SBM) and the American College of Sports Medicine (ACSM), this paper presents a model for physical activity counseling for primary care physicians (PCPs). Most US adults do not meet national recommendations for physical activity levels. Socioecological factors drive differences in physical activity levels by geography, sex, age, and racial/ethnic group. The recent Patient Protection and Affordable Care Act incentivizes PCPs to offer patients physical activity counseling. However, PCPs have reported socioecological barriers to physical activity counseling and also patient barriers to physical activity, spanning from the individual to the environmental (eg, lack of safe spaces for physical activity), policy (eg, reimbursement policies), and organizational (eg, electronic medical record protocols, worksite norms/policies) levels. The aims of this paper are to: 1) discuss barriers to PCP counseling for physical activity; 2) provide evidence-based strategies and techniques to help PCPs address these counseling barriers; and 3) suggest practical steps for PCPs to counsel patients on physical activity using strategies and supports from policy, the primary care team, and other support networks.

Intra-individual and inter-individual variability in daily sitting time and MVPA.

OBJECTIVES: Little is known about how much variability exists in free-living sitting time within individuals. The purpose of this study was to examine intra-individual variability of objectively determined daily sitting time and to determine if this variability was related to weekly averages of sitting duration or recommended moderate-vigorous physical activity (MVPA). Also, this study determined the reliability of free-living sitting and MVPA time as it useful for guiding researchers in determining how many days of monitoring are needed. DESIGN: An activPAL monitor was worn for 7 consecutive days by 68 women (52±8 years). METHODS: Intra-individual range of daily sitting time was calculated. Generalizability theory analysis determined the reliability of daily sitting and recommended MVPA. RESULTS: Mean sitting time was 9.0±1.8h/day and the within individual weekly mean range was 4.5±1.7h/day. Similarly, there was a 4.5h/day difference in sitting time between the mean of the lowest sitting (6.7±0.8) and highest sitting (11.3±1.1h/day) quartiles. The intra-individual range in daily sitting did not differ among quartiles of sitting time (i.e., 4.9±1.9, 4.1±1.9, 5.1±1.5, 3.9±1.1h/day for the 1st-4th quartiles) nor among quartiles of MVPA (i.e., 4.2±1.8, 4.7±2.0, 4.6±1.5, 4.4±1.3h/day for the 1st-4th quartiles). A reliability coefficient of 0.80 was achieved with 4 days of objectively measured sitting time and 7 days for MVPA. CONCLUSIONS: The findings suggest exposure to relatively high levels of sedentary time may occur in people regardless of weekly averages in sitting and regular exercise due to the high day-to-day variation in daily sitting time (4.5h/d range within a week).

Leisure-Time Spent Sitting and Site-Specific Cancer Incidence in a Large U.S. Cohort.

BACKGROUND: Time spent sitting is distinctly different from accumulating too little physical activity and may have independent deleterious effects. Few studies have examined the association between sitting time and site-specific cancer incidence. METHODS: Among 69,260 men and 77,462 women who were cancer-free and enrolled in the American Cancer Society Cancer Prevention Study II Nutrition Cohort, 18,555 men and 12,236 women were diagnosed with cancer between 1992 and 2009. Extended Cox proportional hazards regression was used to estimate multivariable-adjusted relative risks (RR) and 95% confidence intervals (CI) of leisure-time spent sitting with total and site-specific cancer incidence. RESULTS: Longer leisure-time spent sitting, after adjustment for physical activity, BMI, and other factors, was associated with risk of total cancer in women (RR = 1.10; 95% CI, 1.04-1.17 for ≥6 hours vs. <3 hours per day), but not men (RR = 1.00; 95% CI, 0.96-1.05). In women, sitting time was associated with risk of multiple myeloma (RR = 1.65; 95% CI, 1.07-2.54), invasive breast cancer (RR = 1.10; 95% CI, 1.00-1.21), and ovarian cancer (RR = 1.43; 95% CI, 1.10-1.87). There were no associations between sitting time and site-specific cancers in men. CONCLUSION: Longer leisure-time spent sitting was associated with a higher risk of total cancer risk in women, and specifically with multiple myeloma, breast, and ovarian cancers, but sitting time was not associated with cancer risk in men. Further research is warranted to better understand the differences in associations between men and women. IMPACT: For women, these findings support American Cancer Society guidelines for cancer prevention to reduce sitting time when possible.

Life stage influences on U.S. South Asian women's physical activity.

PURPOSE: South Asian (SA) women in the United States report extremely low rates of leisure time physical activity (PA) compared with women in other ethnic minority groups. This study explored SA women's perspectives on PA during different life stages. DESIGN: This is a community-based participatory research study that used focus groups. SETTING: The study setting was a community-based organization that provides social services to SA immigrants in Chicago, Illinois. PARTICIPANTS: The study team conducted six focus groups (in English and Hindi) with 42 SA women, ages 18 to 71 years. METHOD: A semistructured interview guide was used to foster discussion about perceptions of, barriers to/facilitators of, and suggestions for PA programs. Discussions were transcribed and independently coded by two reviewers using thematic content analysis and guided by a coding scheme that was developed a priori. RESULTS: Participants said that different life stages strongly influenced their PA. PA decreased after marriage and having children. Chronic diseases constrained older women from more vigorous PA. Barriers to PA among younger women were family disapproval and perceptions that PA is unnecessary if you are "skinny." Women agreed that PA is not a priority within the culture, and that interventions must take into account cultural, religious, and family context. CONCLUSION: Sociocultural norms, family constraints, and lack of awareness about the benefits of PA strongly influenced PA among SA women. Culturally salient intervention strategies might include programs in trusted community settings where women can exercise in women-only classes with their children, and targeted education campaigns to increase awareness about the benefits of PA across life stages.

A latent class analysis of cancer risk behaviors among U.S. college students.

OBJECTIVE: The purpose of this study is to understand how cancer risk behaviors cluster in U.S. college students and vary by race and ethnicity. METHODS: Using the fall 2010 wave of the National College Health Assessment (NCHA), we conducted a latent class analysis (LCA) to evaluate the clustering of cancer risk behaviors/conditions: tobacco use, physical inactivity, unhealthy diet, alcohol binge drinking, and overweight/obesity. The identified clusters were then examined separately by students' self-reported race and ethnicity. RESULTS: Among 30,093 college students surveyed, results show a high prevalence of unhealthy diet as defined by insufficient fruit and vegetable intake (>95%) and physical inactivity (>60%). The LCA identified behavioral clustering for the entire sample and distinct clustering among Black and American Indian students. CONCLUSIONS: Cancer risk behaviors/conditions appear to cluster among college students differentially by race. Understanding how risk behaviors cluster in young adults can lend insight to racial disparities in cancer through adulthood. Health behavior interventions focused on modifying multiple risk behaviors and tailored to students' racial group could potentially have a much larger effect on cancer prevention than those targeting any single behavior.

Sedentary screen time and left ventricular structure and function: the CARDIA study.

INTRODUCTION: Sedentary screen time (watching TV or using a computer) predicts cardiovascular outcomes independently from moderate and vigorous physical activity and could affect left ventricular structure and function through the adverse consequences of sedentary behavior. PURPOSE: This study aimed to determine whether sedentary screen time is associated with measures of left ventricular structure and function. METHODS: The Coronary Artery Risk Development in Young Adults Study measured screen time by questionnaire and left ventricular structure and function by echocardiography in 2854 black and white participants, age 43-55 yr, in 2010-2011. Generalized linear models evaluated cross-sectional trends for echocardiography measures across higher categories of screen time and adjusting for demographics, smoking, alcohol, and physical activity. Further models adjusted for potential intermediate factors (blood pressure, antihypertensive medication use, diabetes, and body mass index). RESULTS: The relationship between screen time and left ventricular mass (LVM) differed in blacks versus whites. Among whites, higher screen time was associated with larger LVM (P < 0.001), after adjustment for height, demographics, and lifestyle variables. Associations between screen time and LVM persisted when adjusting for blood pressure, antihypertensive medication use, and diabetes (P = 0.008) but not with additional adjustment for body mass index (P = 0.503). Similar relationships were observed for screen time with LVM indexed to height, relative wall thickness, and mass-to-volume ratio. Screen time was not associated with left ventricular structure among blacks or left ventricular function in either race group. CONCLUSIONS: Sedentary screen time is associated with greater LVM in white adults, and this relationship was largely explained by higher overall adiposity. The lack of association in blacks supports a potential qualitative difference in the cardiovascular consequences of sedentary screen-based behavior.

Evidence that women meeting physical activity guidelines do not sit less: an observational inclinometry study.

BACKGROUND: The inactivity physiology paradigm proposes that sedentary behaviors, including sitting too much, are independent of the type of physical activity delineated for health in the Physical Activity Guidelines for Americans. Thus, we hypothesized that, when accounting for behaviors across the entire day, variability in the amount of time spent sitting would be independent of the inter-and intra-individual time engaged in sustained moderate-to-vigorous physical activity (MVPA). METHODS: Ninety-one healthy women, aged 40-75 years, completed a demographic questionnaire and assessment of height and weight. Participants wore the activPAL activity monitor for one week and time (minutes/day) spent sitting, standing, stepping, and in sustained bouts (bouts ≥10 minutes) of MVPA were quantified. The women were then stratified into groups based on weekly sustained MVPA. Additionally, each day of data collection for each participant was classified as either a "sufficient" MVPA day (≥ 30 min of MVPA) or an "insufficient" MVPA day for within-participant analyses. RESULTS: Time spent sitting, standing, and in incidental non-exercise stepping averaged 64, 28, and 11 hrs/week, respectively, and did not differ between groups with individuals meeting/exceeding the current exercise recommendation of 150 min/week of sustained MVPA in ≥10 minutes bouts (M = 294 min/week, SD = 22) compared to those with none or minimal levels (M= 20 min/week, SD = 4). Time spent sitting (M = 9.1 hr/day, SD = 0.19 vs. M = 8.8 hr/day, SD = 0.22), standing (M = 3.9 hr/day, SD = 0.16 vs. M = 3.9 hr/day, SD = 0.15), and in intermittent stepping (M = 1.6 hr/day, SD = 0.07 vs. M = 1.6 hr/day, SD = 0.06) did not differ between days with (~55 min/day) and without recommended MVPA. CONCLUSIONS: This study provides the first objective evidence that participation in sustained MVPA is unrelated to daily sitting duration in relatively healthy, middle and older-aged women. More research is needed to extend these findings to other populations and to inform distinct behavioral recommendations focused on sedentary time.

Meta-analysis of efficacy of interventions for elevated depressive symptoms in adults diagnosed with cancer.

BACKGROUND: Cancer patients are at increased risk for depression compared with individuals with no cancer diagnosis, yet few interventions target depressed cancer patients. METHODS: Efficacy of psychotherapeutic and pharmacologic interventions for depression in cancer patients who met an entry threshold for depressive symptoms was examined by meta-analysis. Five electronic databases were systematically reviewed to identify randomized controlled trials meeting the selection criteria. Effect sizes were calculated using Hedges' g and were pooled to compare pre- and postrandomization depressive symptoms with a random effects model. Subgroup analyses tested moderators of effect sizes, such as comparison of different intervention modalities, with a mixed effects model. All statistical tests were two-sided. RESULTS: Ten randomized controlled trials (six psychotherapeutic and four pharmacologic studies) met the selection criteria; 1362 participants with mixed cancer types and stages had been randomly assigned to treatment groups. One outlier trial was removed from analyses. The random effects model showed interventions to be superior to control conditions on reducing depressive symptoms postintervention (Hedges' g = 0.43, 95% confidence interval = 0.30 to 0.56, P < .001). In the four psychotherapeutic trials with follow-up assessment, interventions were more effective than control conditions up to 12-18 months after patients were randomly assigned to treatment groups (P < .001). Although each approach was more effective than the control conditions in improving depressive symptoms (P < .001), subgroup analyses showed that cognitive behavioral therapy appeared more effective than problem-solving therapy (P = .01), but not more effective than pharmacologic intervention (P = .07). CONCLUSIONS: Our findings suggest that psychological and pharmacologic approaches can be targeted productively toward cancer patients with elevated depressive symptoms. Research is needed to maximize effectiveness, accessibility, and integration into clinical care of interventions for depressed cancer patients.

Longitudinal associations of leisure-time physical activity and cancer mortality in the Third National Health and Nutrition Examination Survey (1986-2006).

Longitudinal associations between leisure-time physical activity (LTPA) and overall cancer mortality were evaluated within the Third National Health and Nutrition Examination Survey (NHANES III; 1988-2006; n = 15,535). Mortality status was ascertained using the National Death Index. Self-reported LTPA was divided into inactive, regular low-to-moderate and vigorous activity. A frequency-weighted metabolic equivalents (METS/week) variable was also computed. Hazard ratios (HRs) and 95% confidence intervals (CI) were calculated for overall cancer mortality in the whole sample, by body mass index categories and insulin resistance (IR) status. Nonsignificant protective associations were observed for regular low-to-moderate and vigorous activity, and for the highest quartile of METS/week (HRs range: 0.66-0.95). Individuals without IR engaging in regular vigorous activity had a 48% decreased risk of cancer mortality (HR: 0.52; 95% CI: 0.28-0.98) in multivariate analyses. Conversely, nonsignificant positive associations were observed in people with IR. In conclusion, regular vigorous activity may reduce risk of cancer mortality among persons with normal insulin-glucose metabolism in this national sample.

Association of sex hormones and sex hormone-binding globulin with depressive symptoms in postmenopausal women: the Multiethnic Study of Atherosclerosis.

OBJECTIVE: Sex hormones are thought to play an important role in the pathophysiology of depressive disorders in women. This study assessed the associations of total testosterone (T), bioavailable T, estradiol, dehydroepiandrosterone, and sex hormone-binding globulin (SHBG) with depressive symptoms stratified on postmenopausal stage to determine whether the associations were strongest for early postmenopausal women. METHODS: Women (N = 1,824) free of depressive symptoms at baseline (2000-2002) in the Multiethnic Study of Atherosclerosis were categorized into tertiles of years postmenopause: T1, 0 to 10 years; T2, 11 to 20 years; and T3, 21 to 58 years. Multivariable-adjusted relative risks (RRs) and 95% CIs were computed for the incidence of depressive symptoms, as defined by a score of 16 or higher on the Center for Epidemiologic Studies Depression scale at examination 3 (2004-2005). RESULTS: In analysis including all sex hormones, the RR for incident depressive symptoms associated with 1 unit higher log total T was 0.57 (P = 0.13), with log estradiol was 0.78 (P = 0.04), with log SHBG was 1.84 (P = 0.003), and with log dehydroepiandrosterone was 1.45 (P = 0.08) in T1. Without adjustment for SHBG, the RR for log bioavailable T was 0.16 (P = 0.04). However, in T2 and T3, there were no meaningful associations of hormone or SHBG levels with incident depressive symptoms. When stratified by HT use, results were consistent for HT users but attenuated for HT nonusers. CONCLUSIONS: In early postmenopausal women, sex hormones were associated with incident depressive symptoms.

Exercise effects on depressive symptoms in cancer survivors: a systematic review and meta-analysis.

BACKGROUND: Depression is a distressing side effect of cancer and its treatment. In the general population, exercise is an effective antidepressant. OBJECTIVE: We conducted a systematic review and meta-analysis to determine the antidepressant effect of exercise in cancer survivors. DATA SOURCES: In May 2011, we searched MEDLINE, PsycInfo, EMBASE, CINAHL, CDSR, CENTRAL, AMED, Biosis Previews, and Sport Discus and citations from relevant articles and reviews. STUDY ELIGIBILITY CRITERIA: We included randomized controlled trials (RCT) comparing exercise interventions with usual care in cancer survivors, using a self-report inventory or clinician rating to assess depressive symptoms, and reporting symptoms pre- and postintervention. STUDY APPRAISAL: Around 7,042 study titles were identified and screened, with 15 RCTs included. SYNTHESIS METHODS: Effect sizes (ES) were reported as mean change scores. The Q test was conducted to evaluate heterogeneity of ES. Potential moderator variables were evaluated with examination of scatter plots and Wilcoxon rank-sum or Kruskal-Wallis tests. RESULTS: The overall ES, under a random-effects model, was -0.22 (confidence interval, -0.43 to -0.09; P = 0.04). Significant moderating variables (ps < 0.05) were exercise location, exercise supervision, and exercise duration. LIMITATIONS: Only one study identified depression as the primary endpoint. CONCLUSIONS: Exercise has modest positive effects on depressive symptoms with larger effects for programs that were supervised or partially supervised, not conducted at home, and at least 30 minutes in duration. IMPACT: Our results complement other studies showing that exercise is associated with reduced pain and fatigue and with improvements in quality of life among cancer survivors.

Physical activity during daily life and circulating biomarker levels in patients with peripheral arterial disease.

Higher levels of inflammation are associated with adverse outcomes in patients with lower extremity peripheral arterial disease (PAD). This study evaluated associations of physical activity during daily life with levels of inflammatory biomarkers, D-dimer, and homocysteine in patients with PAD. Participants were 244 men and women (mean age 74.4 +/- 8.2 years) with PAD (ankle brachial index <0.90). C-reactive protein, interleukin-6, soluble intracellular adhesion molecule-1, soluble vascular cellular adhesion molecule-1, D-dimer, and homocysteine were assessed at study entry. Physical activity was objectively assessed with a vertical accelerometer, which participants wore continuously for 7 days. After adjusting for age, gender, race, body mass index, smoking, co-morbidities, ankle brachial index, and other potential confounders, higher physical activity levels were associated linearly and significantly with lower levels of all measured circulating biomarkers: soluble vascular cellular adhesion molecule-1 (p trend = 0.001), D-dimer (p trend = 0.005), homocysteine (p trend = 0.006), interleukin-6 (p trend = 0.010), C-reactive protein (p trend = 0.028), and soluble intracellular adhesion molecule-1 (p trend = 0.033). In conclusion, higher levels of physical activity were associated independently with lower levels of inflammatory markers, homocysteine, and D-dimer in patients with PAD.

Psychosocial correlates of exercise in women with self-reported depressive symptoms.

BACKGROUND: Exercise effectively reduces symptoms of depression. However, correlates of regular exercise in depressed women are unknown. This study assessed psychosocial determinants of exercise in a sample of women with depressive symptoms. METHODS: Sixty-one women completed demographic, depression, and exercise-related questionnaires. RESULTS: The average Primary Health Questionnaire-9 (PHQ-9) depression score was 12.1 (SD = 5.0), indicating moderate depressive symptoms. In the previous week, the women reported 12.8 metabolic equivalents (METs) of exercise. Low levels of self-efficacy and social support for exercise were also reported. Depressive symptoms were positively associated with barriers to exercise (r = .35, P < .01), and barriers were inversely related to exercise METs (r = -.37, P < .05). Barriers to activity and education level were significant determinants of exercise. CONCLUSIONS: Women with depressive symptoms report minimal exercise involvement, numerous barriers to exercise, and low exercise self-efficacy and social support for exercise.

Autonomic regulation of the association between exercise and diabetes.

The inverse association between physical activity and diabetes is attributable to a number of biologically plausible mechanisms. We hypothesize that physical activity-induced improvements in autonomic function are one mechanism by which higher levels of activity are inversely associated with diabetes development. Evidence in support of our hypothesis is derived from a combination of observational studies and clinical trials.