This study investigated associations between objectively measured physical activity (PA) with sarcopenia and sarcopenic obesity in older British men. Participants were men aged 70–92 years (n = 1286) recruited from UK Primary Care Centres. Outcomes included (i) sarcopenia, defined as low muscle mass (lowest two fifths of the mid-upper arm muscle circumference distribution) accompanied by low muscular strength (hand grip strength < 30 kg) or low physical performance (gait speed ≤ 0.8 m/s); (ii) severe sarcopenia, required all three conditions; (iii) sarcopenic obesity defined as sarcopenia or severe sarcopenia and a waist circumference of > 102 cm. Independent variables included time spent in PA intensities measured by GT3x accelerometers, worn during one week in 2010–12. Multinomial regression models were used for cross-sectional analyses relating PA and sarcopenia. In total, 14.2% (n = 183) of men had sarcopenia and a further 5.4% (n = 70) had severe sarcopenia. 25.3% of sarcopenic or severely sarcopenic men were obese. Each extra 30 min per day of moderate-to-vigorous PA (MVPA) was associated with a reduced risk of severe sarcopenia (relative risk [RR] 0.53, 95% confidence interval [CI] 0.30, 0.93) and sarcopenic obesity (RR 0.47 [95% CI 0.27, 0.84]). Light PA (LPA) and sedentary breaks were marginally associated with a reduced risk of sarcopenic obesity. Sedentary time was marginally associated with an increased risk of sarcopenic obesity independent of MVPA (RR 1.18 [95% CI 0.99, 1.40]). MVPA may reduce the risk of severe sarcopenia and sarcopenic obesity among older men. Reducing sedentary time and increasing LPA and sedentary breaks may also protect against sarcopenic obesity.

BackgroundThe effects of replacing time in specific activity categories for other categories (e.g. replacing sedentary time with light activity) on health and fitness are not well known. This study used isotemporal substitution to investigate the effects of substituting activity categories in an equal time exchange fashion on health and fitness in young people.MethodsParticipants were drawn from schools in Camden, London (n = 353, mean age 9.3 ± 2.3 years). Time sedentary, in light and in moderate-to-vigorous activity (MVPA) was measured via accelerometry. The effects of substituting time in activity categories (sedentary, light and MVPA) with equivalent time in another category on health and fitness were examined using isotemporal substitution.ResultsIn single and partition models, MVPA was favourably associated with body fat %, horizontal jump distance and flexibility. Time sedentary and in light activity were not associated with health and fitness outcomes in these models. In substitution models, replacing one hour of sedentary time with MVPA was favourably associated with body fat % (B = −4.187; 95 % confidence interval (CI), −7.233, −1.142), horizontal jump distance (B = 16.093; 95 % CI, 7.476, 24.710) and flexibility (B = 4.783; 95 % CI, 1.910, 7.656). Replacing time in light activity with MVPA induced similar benefits but there were null effects for replacing sedentary with light intensity.ConclusionSubstituting time sedentary and in light activity with MVPA was associated with favourable health and fitness. Time in sedentary behaviour may only be detrimental to health and fitness when it replaces time in MVPA in young people.Electronic supplementary materialThe online version of this article (doi:10.1186/s12966-015-0249-6) contains supplementary material, which is available to authorized users.

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IntroductionIt is well established that physical activity (PA) protects against mortality and morbidity, but how long-term patterns of PA are associated with mortality and cardiovascular disease (CVD) remains unclear.Methods3231 men recruited to the British Regional Heart Study, a prospective cohort study, reported usual PA levels at baseline in 1978–1980 (aged 40–59 years) and at 12-year, 16-year and 20-year follow ups. Twenty-year trajectories of PA, spanning from 1978/1980 to 2000, were identified using group-based trajectory modelling. Men were subsequently followed up until 30 June 2016 for mortality through National Health Service central registers and for non-fatal CVD events through primary and secondary care records. Data analyses were conducted in 2019.ResultsThree PA trajectories were identified: low/decreasing (22.7%), light/stable (51.0%) and moderate/increasing (26.3%). Over a median follow-up of 16.4 years, there were 1735 deaths. Compared with the low/decreasing group, membership of the light/stable (HR 0.83, 95% CI 0.74 to 0.94) and moderate/increasing (HR 0.76, 95% CI 0.66 to 0.88) groups was associated with a lower risk of all-cause mortality. Similar associations were observed for CVD mortality, major coronary heart disease and all CVD events. Associations were only partially explained by a range of confounders. Sensitivity analyses suggested that survival benefits were largely driven by most recent/current PA.ConclusionsA dose-response relationship was observed, with higher levels of PA from midlife to old age associated with additional benefits. However, even fairly modest and sustained PA was protective and may be more achievable for the most inactive.

BackgroundOf all age groups, older adults spend most of the time sitting and are least physically active. This sequential, mixed-methods feasibility study used a randomised controlled trial design to assess methods for trialling a habit-based intervention to displace older adults’ sedentary behaviour with light activity and explore impact on behavioural outcomes.MethodsEligibility criteria were age 60–74 years, retired, and ≥6 h/day leisure sitting. Data were collected across four sites in England. The intervention comprised a booklet outlining 15 ‘tips’ for disrupting sedentary habits and integrating activity habits into normally inactive settings, and eight weekly self-monitoring sheets. The control was a non-habit-based factsheet promoting activity and sedentary reduction. A computer-generated 1:1 block-randomisation schedule was used, with participants blinded to allocation. Participants self-reported sedentary behaviour (two indices), sedentary habit, physical activity (walking, moderate, vigorous activity) and activity habit, at pre-treatment baseline, 8- and 12-week follow-ups and were interviewed at 12 weeks. Primary feasibility outcomes were attrition, adverse events and intervention adherence. The secondary outcome was behavioural change.ResultsOf 104 participants consented, 103 were randomised (intervention N = 52, control N = 51). Of 98 receiving allocated treatment, 91 (93%; intervention N = 45; control N = 46) completed the trial. One related adverse event was reported in the intervention group. Mean per-tip adherence across 7 weeks was ≥50% for 9/15 tips. Qualitative data suggested acceptability of procedures, and, particularly among intervention recipients, the allocated treatment. Both groups appeared to reduce sedentary behaviour and increase their physical activity, but there were no apparent differences between groups in the extent of change.ConclusionsTrial methods were acceptable and feasible, but the intervention conferred no apparent advantage over control, though it was not trialled among the most sedentary and inactive population for whom it was developed. Further development of the intervention may be necessary prior to a large-scale definitive trial. One possible refinement would combine elements of the intervention with an informational approach to enhance effectiveness.Trial registration ISRCTN47901994 (registration date: 16th January 2014; trial end date 30th April 2015)Electronic supplementary materialThe online version of this article (doi:10.1186/s40814-017-0139-6) contains supplementary material, which is available to authorized users.

BackgroundMaintenance of physical activity (PA) during later life is associated with optimal health; however, the long-term trajectories of PA into old age and their predictors have not been extensively researched using latent class methods. This study aimed to identify trajectories of self-reported PA and their predictors in men transitioning from midlife to old age.Methods7735 men (aged 40–59 years) recruited in 1978–80 were followed up after 12, 16 and 20 years, reporting PA, health status, lifestyle behaviours and socio-demographic characteristics. Group-based trajectory modelling identified the trajectories of PA and associations with time-stable and time-varying covariates. We considered a range of sociodemographic and health and lifestyle factors as potential covariates.Results4952 men (mean baseline age 49.1 ± 5.6 years) providing PA data at ≥3 time points were included in analyses. Three distinct 20-year trajectories were identified: low decreasing (24.6%, n = 1218), light stable (51.1%, n = 2530) and moderate increasing (24.3%, n = 1204). Being older, having a manual occupation, having never married or had children, residing in the midlands or North of England, suffering from a range of health conditions, being a smoker/ex-smoker and never consuming breakfast cereal or alcohol were independently associated with reduced odds of belonging to the moderate increasing trajectory group compared to the low decreasing group. Of the time-varying covariates considered, leaving employment was associated with a decrease in PA in the low decreasing group (β −0.306, p < 0.001) but an increase in the light stable (β 0.324, p < 0.001) and moderate increasing groups (β 0.847, p < 0.001). Developing cardiovascular-related conditions was associated with a decrease in PA in the low decreasing (β −0.408, p < 0.001) and light stable groups (β −0.118, p < 0.001) but no association was observed in the moderate increasing group (β −0.060, p = 0.313).ConclusionsThree distinct trajectories of PA were identified in men transitioning from midlife to old age, of which nearly a quarter had persistently low levels of PA. Promotion efforts may need to focus attention prior to middle age and consider a number of sociodemographic, health and lifestyle factors to sustain PA into old age. The effects of retirement and development of cardiovascular disease may vary according to PA trajectories.Electronic supplementary materialThe online version of this article (10.1186/s12966-017-0642-4) contains supplementary material, which is available to authorized users.

In the present study, we investigated how overall and specific domains of physical activity and sedentary behavior at the age of 7 years were associated with cognition at the age of 11 years in 8,462 children from the Millennium Cohort Study. Data were collected from 2001 to 2013. Participation in domains of physical activity and sedentary behavior at 7 years of age were reported. Activity levels were also measured objectively. Cognition was assessed using the British Ability Scales. General linear models were used to assess longitudinal associations of physical activity and sedentary behavior, measured both objectively and via self-report, with cognition. Analyses were adjusted for prespecified covariates. Sports/physical activity club attendance (B = 0.6, 95% confidence interval (CI): 0.2, 1.1), doing homework (B = 0.5, 95% CI: 0.0, 0.9), and objectively measured sedentary time (B = 0.8, 95% CI: 0.1, 1.4) at age 7 years were positively associated with cognition at age 11 years in final the models. Television viewing was negatively associated with cognition (B = −1.7, 95% CI: −2.4, −1.0), although the association was attenuated to the null after adjustments for baseline cognition. Objectively measured light physical activity was inversely associated with cognition (B = −0.7, 95% CI: −1.3, −0.1). Moderate-to-vigorous physical activity was also inversely associated with cognition in girls only (B = −1.1, 95% CI: −2.0, −0.3). Associations of physical activity and sedentary behavior with cognition appear to be context-specific in young people.

BackgroundThe physical school environment is a promising setting to increase children’s physical activity although robust evidence is sparse. We examined the effects of major playground reconstruction on physical activity and sedentary time in primary schools using a quasi-experimental design (comparison group pre-test/post-test design).MethodsFive experimental and two control schools from deprived areas of inner city London were recruited at baseline. Main outcome was physical activity and sedentary time measured from objective monitoring (Actigraph accelerometer) at one year follow up. Pupils’ impressions of the new playground were qualitatively assessed post construction.ResultsA total of 347 pupils (mean age = 8 years, 55% boys; 36% Caucasian) were recruited into the study at baseline; 303 provided valid baseline Actigraph data. Of those, 231 (76%) completed follow-up (n = 169 intervention; n = 62 control) and 77.4% of the sample recorded at least 4 days of Actigraph wear. In mixed models adjusted for age, sex, ethnicity, ratio activity or sedentary/wear time at baseline, wear time at follow up, and school, no differences were observed in total moderate – vigorous activity (B = −1.4, 95% CI, −7.1, 4.2 min/d), light activity (B = 4.1, 95% CI, −17.9, 26.1), or sedentary time (B = −3.8, 95% CI, −29.2, 21.6 min/d) between groups. There were significant age interactions for sedentary (p = 0.002) and light intensity physical activity (p = 0.008). We observed significant reductions in total sedentary (−28.0, 95% CI, −1.9, −54.1 min/d, p = 0.037) and increases in total light intensity activity (24.6, 95% CI, 0.3, 48.9 min/d, p = 0.047) for children aged under 9 yrs. old in the intervention.ConclusionMajor playground reconstruction had limited effects on physical activity, but reduced sedentary time was observed in younger children. Qualitative data suggested that the children enjoyed the new playgrounds and experienced a perceived positive change in well-being and social interactions.Electronic supplementary materialThe online version of this article (doi:10.1186/s12889-017-4483-5) contains supplementary material, which is available to authorized users.