Physical activity levels in adults and elderly from triaxial and uniaxial accelerometry. The Tromsø Study.

INTRODUCTION:Surveillance of physical activity at the population level increases the knowledge on levels and trends of physical activity, which may support public health initiatives to promote physical activity. Physical activity assessed by accelerometry is challenged by varying data processing procedures, which influences the outcome. We aimed to describe the levels and prevalence estimates of physical activity, and to examine how triaxial and uniaxial accelerometry data influences these estimates, in a large population-based cohort of Norwegian adults. METHODS:This cross-sectional study included 5918 women and men aged 40-84 years who participated in the seventh wave of the Tromsø Study (2015-16). The participants wore an ActiGraph wGT3X-BT accelerometer attached to the hip for 24 hours per day over seven consecutive days. Accelerometry variables were expressed as volume (counts·minute-1 and steps·day-1) and as minutes per day in sedentary, light physical activity and moderate and vigorous physical activity (MVPA). RESULTS:From triaxial accelerometry data, 22% (95% confidence interval (CI): 21-23%) of the participants fulfilled the current global recommendations for physical activity (≥150 minutes of MVPA per week in ≥10-minute bouts), while 70% (95% CI: 69-71%) accumulated ≥150 minutes of non-bouted MVPA per week. When analysing uniaxial data, 18% fulfilled the current recommendations (i.e. 20% difference compared with triaxial data), and 55% (95% CI: 53-56%) accumulated ≥150 minutes of non-bouted MVPA per week. We observed approximately 100 less minutes of sedentary time and 90 minutes more of light physical activity from triaxial data compared with uniaxial data (p<0.001). CONCLUSION:The prevalence estimates of sufficiently active adults and elderly are more than three times higher (22% vs. 70%) when comparing triaxial bouted and non-bouted MVPA. Physical activity estimates are highly dependent on accelerometry data processing criteria and on different definitions of physical activity recommendations, which may influence prevalence estimates and tracking of physical activity patterns over time

DEVELOPMENT OF THE MUNICIPAL NOISE-ABSORBING SCREEN AND TEST SECTION CONSTRUCTION TECHNOLOGY

The article presents the development and construction technology of the Municipal noise-absorbing screen (MNAS) – in Czech "Mestská protihluková clona" (MPHC). The Municipal noise-absorbing screen is a new acoustical element developed in cooperation of the Department of Railway Structures, Faculty of Civil Engineering, CTU in Prague and the Montstav CZ s.r.o. Company. It is characterised by very small dimensions – its height is only ca 0.3 metre above the top of rail. The element serves to attenuate the noise induced by rail traffic arising at the wheel-rail contact. The Municipal noise-absorbing screen consists of individual, mutually interlocked units, placed one after another, made of bound recycled rubber. The article describes the major limiting conditions for the placement, shape and execution of the Municipal noise-absorbing screen. It also describes the construction of the test section situated on a tram track in Prague and sums up the experience obtained after the first year of operation

Device-measured physical activity, sedentary time, and risk of all-cause mortality : an individual participant data analysis of four prospective cohort studies

Objectives: To examine whether moderate-to-vigorous physical activity (MVPA) modifies the association between sedentary time and mortality and vice versa, and estimate the joint associations of MVPA and sedentary time on mortality risk. Methods: This study involved individual participant data analysis of four prospective cohort studies (Norway, Sweden, USA, baseline: 2003-2016, 11 989 participants ≥50 years, 50.5% women) with hip-accelerometry-measured physical activity and sedentary time. Associations were examined using restricted cubic splines and fractional polynomials in Cox regressions adjusted for sex, education, body mass index, smoking, alcohol, study cohort, cardiovascular disease, cancer, and/or diabetes, accelerometry wear time and age. Results: 6.7% (n=805) died during follow-up (median 5.2 years, IQR 4.2 years). More than 12 daily sedentary hours (reference 8 hours) was associated with mortality risk only among those accumulating &lt;22 min of MVPA per day (HR 1.38, 95% CI 1.10 to 1.74). Higher MVPA levels were associated with lower mortality risk irrespective of sedentary time, for example, HR for 10 versus 0 daily min of MVPA was 0.85 (95% CI 0.74 to 0.96) in those accumulating &lt;10.5 daily sedentary hours and 0.65 (95% CI 0.53 to 0.79) in those accumulating ≥10.5 daily sedentary hours. Joint association analyses confirmed that higher MVPA was superior to lower sedentary time in lowering mortality risk, for example, 10 versus 0 daily min of MVPA was associated with 28-55% lower mortality risk across the sedentary time spectrum (lowest risk, 10 daily sedentary hours: HR 0.45, 95% CI 0.31 to 0.65). Conclusions: Sedentary time was associated with higher mortality risk but only in individuals accumulating less than 22 min of MVPA per day. Higher MVPA levels were associated with lower mortality risk irrespective of the amount of sedentary time