All-cause mortality effects of replacing sedentary time with physical activity and sleeping using an isotemporal substitution model: a prospective study of 201,129 mid-aged and older adults

Background Sedentary behaviour, sleeping, and physical activity are thought to be independently associated with health outcomes but it is unclear whether these associations are due to the direct physiological effects of each behaviour or because, across a finite 24-hour day, engagement in one behavior requires displacement of another. The aim of this study was to examine the replacement effects of sedentary behaviour (total sitting, television/computer screen time combined), sleeping, standing, walking, and moderate-to-vigorous physical activity on all-cause mortality using isotemporal substitution modelling. Methods Longitudinal analysis (4.22 ± 0 · 9 years follow-up/849,369 person-years) of 201,129 participants of the 45 and Up study aged ≥45 years from New South Wales, Australia. Results Seven thousand four hundred and sixty deaths occurred over follow-up. There were beneficial associations for replacing total sitting time with standing (per-hour HR: 95 % CI: 0.95, 0.94–0.96), walking (0.86, 0.81–0.90), moderate-to-vigorous physical activity (0.88, 0.85–0.90), and sleeping in those sleeping ≤ 7 h/day (0.94, 0.90–0.98). Similar associations were noted for replacing screen time. Replacing one hour of walking or moderate-to-vigorous physical activity with any other activity class was associated with an increased mortality risk by 7–18 %. Excluding deaths in the first 24 months of the follow up and restricting analyses to those who were healthy at baseline did not materially change the above observations. Conclusion Although replacing sedentary behaviour with walking and moderate-to-vigorous physical activity are associated with the lowest mortality risk, replacements with equal amounts of standing and sleeping (in low sleepers only) are also linked to substantial mortality risk reductions

Are sitting occupations associated with increased all-cause, cancer, and cardiovascular disease mortality risk? A pooled analysis of seven British population cohorts

Background: There is mounting evidence for associations between sedentary behaviours and adverse health outcomes, although the data on occupational sitting and mortality risk remain equivocal. The aim of this study was to determine the association between occupational sitting and cardiovascular, cancer and all-cause mortality in a pooled sample of seven British general population cohorts. Methods: The sample comprised 5380 women and 5788 men in employment who were drawn from five Health Survey for England and two Scottish Health Survey cohorts. Participants were classified as reporting standing, walking or sitting in their work time and followed up over 12.9 years for mortality. Data were modelled using Cox proportional hazard regression adjusted for age, waist circumference, self-reported general health, frequency of alcohol intake, cigarette smoking, nonoccupational physical activity, prevalent cardiovascular disease and cancer at baseline, psychological health, social class, and education. Results: In total there were 754 all-cause deaths. In women, a standing/walking occupation was associated with lower risk of all-cause (fully adjusted hazard ratio [HR] = 0.68, 95% CI 0.52–0.89) and cancer (HR = 0.60, 95% CI 0.43–0.85) mortality, compared to sitting occupations. There were no associations in men. In analyses with combined occupational type and leisure-time physical activity, the risk of all-cause mortality was lowest in participants with non-sitting occupations and high leisure-time activity. Conclusions: Sitting occupations are linked to increased risk for all-cause and cancer mortality in women only, but no such associations exist for cardiovascular mortality in men or women

Supplementary information files for Untapping the health enhancing potential of vigorous intermittent lifestyle physical activity (VILPA): rationale, scoping review, and a 4-pillar research framework

Supplementary files for article Untapping the health enhancing potential of vigorous intermittent lifestyle physical activity (VILPA): rationale, scoping review, and a 4-pillar research framework. Recently revised public health guidelines acknowledge the health benefits of regular intermittent bouts of vigorous intensity incidental physical activity done as part of daily living, such as carrying shopping bags, walking uphill, and stair climbing. Despite this recognition and the advantages such lifestyle physical activity has over continuous vigorous intensity structured exercise, a scoping review we conducted revealed that current research in this area is, at best, rudimentary. Key gaps include the absence of an empirically-derived dose specification (e.g., minimum duration of lifestyle physical activity required to achieve absolute or relative vigorous intensity), lack of acceptable measurement standards, limited understanding of acute and chronic (adaptive) effects of intermittent vigorous bouts on health, and paucity of essential information necessary to develop feasible and scalable interventions (e.g., acceptability of this kind of physical activity by the public). To encourage collaboration and research agenda alignment among groups interested in this field, we propose a research framework to further understanding of vigorous intermittent lifestyle physical activity (VILPA). This framework comprises four pillars aimed at the development of: (a) an empirical definition of VILPA, (b) methods to reliably and accurately measure VILPA, (c) approaches to examine the short and long-term dose–response effects of VILPA, and (d) scalable and acceptable behavioural VILPA-promoting interventions