Background: Subjective measures of sedentary behaviour (SB) (i.e. questionnaires and diaries/logs) are widely implemented, and can be useful for capturing type and context of SBs. However, little is known about comparative validity and reliability. The aim of this systematic review and meta-analysis was to: 1) identify subjective methods to assess overall, domain-and behaviour-specific SB, and 2) examine the validity and reliability of these methods. Methods: The databases MEDLINE, EMBASE and SPORTDiscus were searched up to March 2020. Inclusion criteria were: 1) assessment of SB, 2) evaluation of subjective measurement tools, 3) being performed in healthy adults, 4) manuscript written in English, and 5) paper was peer-reviewed. Data of validity and/or reliability measurements was extracted from included studies and a meta-analysis using random effects was performed to assess the pooled correlation coefficients of the validity. Results: The systematic search resulted in 2423 hits. After excluding duplicates and screening on title and abstract, 82 studies were included with 75 self-reported measurement tools. There was wide variability in the measurement properties and quality of the studies. The criterion validity varied between poor-to-excellent (correlation coefficient [R] range − 0.01-0.90) with logs/diaries (R = 0.63 [95%CI 0.48-0.78]) showing higher criterion validity compared to questionnaires (R = 0.35 [95%CI 0.32-0.39]). Furthermore, correlation coefficients of single-and multiple-item questionnaires were comparable (1-item R = 0.34; 2-to-9-items R = 0.35; ≥10-items R = 0.37). The reliability of SB measures was moderate-to-good, with the quality of these studies being mostly fair-to-good. Conclusion: Logs and diaries are recommended to validly and reliably assess self-reported SB. However, due to time and resources constraints, 1-item questionnaires may be preferred to subjectively assess SB in large-scale observations when showing similar validity and reliability compared to longer questionnaires. Registration number: CRD42018105994.

To lower the risk of hypertension, promoting physical activity and improving fitness, especially CRF, should be encouraged. More research is needed to determine the effects of sedentary behavior, resistance exercise, and muscle strength on the development of hypertension across diverse populations and settings. Future studies should focus on dose-response relationships of exercise and physical activity with the development of hypertension to determine the minimal and optimal amount of exercise and physical activity for hypertension prevention.

Background: Blood concentrations of cardiac troponin above the 99 th percentile are a key criterion for the diagnosis of acute myocardial injury and infarction. Troponin concentrations, even below the 99 th percentile, predict adverse outcomes in patients and the general population. Elevated troponin concentrations are commonly observed after endurance exercise, but the clinical significance of this increase is unknown. We examined the association between postexercise troponin I concentrations and clinical outcomes in long-distance walkers. Methods: We measured cardiac troponin I concentrations in 725 participants (61 [54–69] yrs) before and immediately after 30 to 55 km of walking. We tested for an association between postexercise troponin I concentrations above the 99 th percentile (>0.040 µg/L) and a composite end point of all-cause mortality and major adverse cardiovascular events (myocardial infarction, stroke, heart failure, revascularization, or sudden cardiac arrest). Continuous variables were reported as mean ± standard deviation when normally distributed or median [interquartile range] when not normally distributed. Results: Participants walked 8.3 [7.3–9.3] hours at 68±10% of their maximum heart rate. Baseline troponin I concentrations were >0.040 µg/L in 9 participants (1%). Troponin I concentrations increased after walking ( P <.001), with 63 participants (9%) demonstrating a postexercise troponin concentration >0.040 µg/L. During 43 [23–77] months of follow-up, 62 participants (9%) experienced an end point; 29 died and 33 had major adverse cardiovascular events. Compared with 7% with postexercise troponin I ≤0.040 µg/L (log-rank P <.001), 27% of participants with postexercise troponin I concentrations >0.040 µg/L experienced an end point. The hazard ratio was 2.48 (95% CI, 1.29–4.78) after adjusting for age, sex, cardiovascular risk factors (hypertension, hypercholesterolemia or diabetes mellitus), cardiovascular diseases (myocardial infarction, stroke, or heart failure), and baseline troponin I concentrations. Conclusions: Exercise-induced troponin I elevations above the 99 th percentile after 30 to 55 km of walking independently predicted higher mortality and cardiovascular events in a cohort of older long-distance walkers. Exercise-induced increases in troponin may not be a benign physiological response to exercise, but an early marker of future mortality and cardiovascular events.

Background: Sedentary behaviour (SB) is potentially an important target to improve cardiovascular health. This study 1) compared SB between cardiovascular disease (CVD) patients and age-matched controls, 2) identified characteristics associated with high SB levels, and 3) determined the impact of contemporary cardiac rehabilitation (CR) on SB. Methods: For objective 1, we recruited 131 CVD patients and 117 controls. All participants were asked about their general characteristics and medical history. SB was assessed by an objective accelerometer (activPAL3 micro). For objective 2, 2584 CVD patients were asked to fill in a questionnaire about their general characteristics, lifestyle, medical history and their SB. For objective 3, 131 CVD patients were followed over time and measured, pre-, directly post-and 2 months post-CR. Results: Objective 1. CVD patients spent 10.4 h/day (Q25 9.5; Q75 11.2) sedentary which was higher compared to healthy controls (9.4 h/day [Q25 8.4; Q75 10.29]). Objective 2. CVD patients being male, single or divorced, employed, physically inactive, reporting high alcohol consumption, living in an urban environment, having comorbidities and cardiac anxiety demonstrated a greater odds for large amounts of SB. Objective 3. The CR program significantly reduced sedentary time (−0.4 h/day [95%CI-0.7; −0.1]), which remained lower at 2-months post-CR (−0.3 h/day [95%CI-0.6; −0.03]). Conclusions: CVD patients had greater amounts of objectively measured sedentary time compared to healthy controls. Sedentarism was associated with personal-and lifestyle characteristics, and comorbidities. Participation in a contemporary CR program slightly reduced sedentary time, but tailored interventions are needed to target SB in CVD patients.