Nonworksite Interventions to Reduce Sedentary Behavior among Adults: A Systematic Review.

PURPOSE: Sedentary behavior has been identified as a major health risk. While interventions to reduce time spent sedentary have become increasingly prevalent, the vast majority of this work in adults has been focused on workplace sedentary behavior, and often pairs sedentary reduction interventions with increasing physical activity. As research designed to specifically decrease sedentary time that is not limited to the workplace becomes available, identifying strategies and approaches, along with feasibility and efficacy of these interventions, is warranted. METHODS: Electronic databases were searched for sedentary interventions with eligibility criteria including: (a) interventions designed to explicitly reduce sedentary behavior that were not limited to the workplace, (b) outcomes specific to sedentary behavior, (c) adults aged at least 18 years, and (d) written in English. RESULTS: A total of 767 full-text manuscripts were identified, with thirteen studies meeting all eligibility criteria. While intervention characteristics and methodological quality varied greatly among studies, ten of the thirteen studies observed a significant reduction in objectively measured sitting time post-intervention. In those studies that collected participant feasibility/acceptability data, all reported that the intervention was viewed as "favorable to very favorable," would use again, and that participant burden was quite low, suggesting that these interventions were feasible. CONCLUSION: Sedentary behavior interventions not limited to the workplace appear to be largely efficacious. While results varied with respect to the magnitude of the decrease in time spent sedentary, they are encouraging. However, due to the small body of evidence and the variability of study designs, our ability to make overarching statements regarding "best practices" at this time is limited. Well-controlled trials of longer duration with larger samples, using theoretically-based interventions with consistent prescriptions for limiting sedentary time are needed.

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.

Patterns of sedentary behavior and physical function in older adults.

BACKGROUND/AIMS: The purposes of this study were to examine the relationship between various objectively measured sedentary behavior (SB) variables and physical function in older adults, examine the measurement properties of an SB questionnaire, and describe the domains of SB in our sample. METHODS: Forty-four older adults (70 ± 8 years, 64 % female) had their SB measured via activPAL activity monitor and SB questionnaire for 1 week followed by performance-based tests of physical function. RESULTS: The pattern of SB was more important than total SB time. Where a gender by SB interaction was found, increasing time in SB and fewer breaks were associated with worse function in the males only. The SB questionnaire had acceptable test-retest reliability but poor validity compared to activPAL-measured SB. The majority of SB time was spent watching television, using the computer and reading. DISCUSSION/CONCLUSIONS: This study provides further evidence for the association between SB and physical function and describes where older adults are spending their sedentary time. This information can be used in the design of future intervention to reduce sedentary time and improve function in older adults.

Dose-response relationships between sedentary behaviour and the metabolic syndrome and its components.

AIMS/HYPOTHESIS: The aim of this study was to examine the relationship among sedentary behaviour (SB) and the metabolic syndrome and its components by age, moderate-to-vigorous physical activity (MVPA) and sex. METHODS: A cross-sectional analysis was performed on 2003-2006 National Health and Nutrition Examination Survey data from 5,076 adults aged ≥18 years (mean ± SD = 43.8 ± 19.5). SB was measured using ActiGraph accelerometers worn for 1 week and defined as <100 counts/min. Metabolic syndrome was defined using the Adult Treatment Panel III criteria. Natural cubic spline logistic regression models were used to estimate the odds of meeting criteria for the metabolic syndrome and its components by total daily SB time and breaks in SB. Statistical interactions between SB and age, sex and MVPA were explored. RESULTS: The prevalence of the metabolic syndrome was 19% and the average daily SB time was 8.1 ± 2.8 h, with 90 ± 25 breaks/day. The relationship between daily SB time and the metabolic syndrome was linear and characterised by an OR of 1.09 (95% CI 1.01, 1.18) for each hour of SB. Total SB was associated with the following components: high triacylglycerol, low HDL-cholesterol and high fasting glucose. All three associations were modified by MVPA level. No relationship between breaks in SB and the metabolic syndrome was found. CONCLUSIONS/INTERPRETATION: There appears to be no SB threshold at which the risk of the metabolic syndrome is elevated. Therefore, an effort should be made to maintain low levels of total time spent in SB and so lessen the risk of the metabolic syndrome.

Smokers' physical activity and weight gain one year after a successful versus unsuccessful quit attempt.

OBJECTIVE: To examine whether smokers' physical activity is related to weight change following a quit attempt. METHOD: Data were analyzed for participants (n=683) of a randomized controlled trial comparing the efficacy of different smoking cessation pharmacotherapies (Wisconsin, 2005-2008). Activity (assessed via pedometry) and body weight were measured in the days surrounding the quit day and again one year later, at which time 7-day point-prevalence abstinence from smoking was assessed. We examined the effects of quitting, physical activity, and their interaction, on a one-year weight change with relevant covariate adjustment. RESULTS: Participants were predominantly female (57%), 46 ± 11 years of age (mean ± SD), and took 7544 ± 3606 steps/day at baseline. Of those who quit, 87% gained weight. A main effect was found for quitting (p<0.001), but not physical activity (p=0.06). When pattern of activity was examined across the 1-year study period, quitters who decreased their physical activity had significantly greater weight gain than quitters who increased their physical activity (p<0.01) or maintained a high level of activity (p=0.02). CONCLUSION: Physical activity is associated with an attenuation of the weight gain that often occurs after quitting smoking.

Dose-response relationships between physical activity, social participation, and health-related quality of life in colorectal cancer survivors.

PURPOSE: The purpose of this study was to examine the relationships between physical activity (PA), social participation, and health-related quality of life (HQOL) in older, long-term colorectal cancer survivors. METHODS: Male and female colorectal cancer survivors (n = 1,768), aged ≥65 and ≥5 years post-diagnosis, completed surveys on their current PA, social participation, HQOL, health history, and relevant covariates. Analysis of covariance was used to evaluate the cross-sectional relationship between PA and social participation with the SF-36 subscales, as well as the physical component summary score (PCS) and mental health component summary score (MCS). RESULTS: The final analytic sample (n = 832) was 81.5 ± 5.8 years and 8.2 ± 1.7 years post-diagnosis (mean ± SD). Meeting the current recommendation of 150 min/week of PA was associated with higher PCS (p < 0.001) but not MCS (p = 0.30). Engaging in any social participation, vs. none, was associated with MCS (p = 0.003), but not PCS (p = 0.13). There was a dose-response relationship between moderate-vigorous-intensity PA and PCS (p trend<0.001). Light-intensity PA was not associated with either summary score after adjustment for moderate-vigorous PA (p > 0.05), but in survivors performing no higher-intensity PA, it was associated with both (p < 0.01, p = 0.02, respectively). Participants reporting greater amounts of both planned exercise and non-exercise PA had significantly higher PCS (p trend<0.01, p trend < 0.01, respectively). Individuals participating in greater weekly hours of social participation had higher PCS and MCS (p trend<0.05) than those participating in less. CONCLUSIONS: Among older, long-term colorectal cancer survivors, PA is related to their physical health, while social participation is predominantly related to their mental health. IMPLICATIONS FOR CANCER SURVIVORS: Older colorectal cancer survivors who participate socially and are engaged in PA, even non-exercise and light-intensity activities, have higher levels of physical and mental health.

Sedentary behavior, physical activity, and markers of health in older adults.

INTRODUCTION: The purpose of this study was to examine the association between sedentary behavior (SB), cardiometabolic risk factors, and self-reported physical function by level of moderate-vigorous physical activity (MVPA). METHODS: Cross-sectional analysis was completed on 1914 older adults age ≥ 65 yr from the 2003-2006 U.S. National Health and Nutrition Examination Survey. MVPA and SB were derived from ActiGraph accelerometers worn for 1 wk. MVPA was categorized as sufficient to meet the current U.S. guidelines (≥ 150 min · wk(-1)) or not; SB was split into quartiles. Various biomarkers were examined in laboratory analyses and physical exams, and the number of functional limitations was self-reported. Statistical interaction between SB and MVPA on the biomarker associations was the primary analysis, followed by an examination of their independent associations with relevant covariate adjustment. RESULTS: Average SB was 9.4 ± 2.3 h · d(-1) (mean ± SD), and approximately 35% were classified as sufficiently active. Overall, no significant meaningful statistical interactions were found between SB and MVPA for any of the outcomes; however, strong independent positive associations were found between SB and weight (P < 0.01), body mass index (P < 0.01), waist circumference (P < 0.01), C-reactive protein (P < 0.01), plasma glucose (P = 0.04), and number of functional limitations (P < 0.01) after adjustment for MVPA. Similarly, MVPA was negatively associated with weight (P = 0.01), body mass index (P < 0.01), waist circumference (P < 0.01), diastolic blood pressure (P = 0.04), C-reactive protein (P < 0.01), and number of functional limitations (P < 0.01) after adjustment for SB. CONCLUSIONS: The results suggest that sufficient MVPA did not ameliorate the negative associations between SB and cardiometabolic risk factors or functional limitations in the current sample and that there was independence on a multiplicative scale in their associations with the outcomes examined. Thus, older adults may benefit from the joint prescription to accumulate adequate MVPA and avoid prolonged sitting.