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Background and Aims: Understanding the amounts of intensity-specific movement needed to attenuate the association between sedentary time and mortality may help to inform personalized prescription and behavioral counselling. Herein, we examined the joint associations of sedentary time and intensity-specific physical activity with all-cause and cardiovascular disease (CVD) mortality., Methods: Prospective cohort study including 73,729 adults from the UK Biobank who wore an Axivity AX3 accelerometer on their dominant wrist for at least 3 days, being one a weekend day, between June 2013 and December 2015. We considered the median tertile values of sedentary time and physical activity in each intensity band to determine the amount of physical activity needed to attenuate the association between sedentary time and mortality., Results: During a median of 6.9 years of follow-up (628,807 person-years), we documented 1521 deaths, including 388 from CVD. Physical activity of any intensity attenuated the detrimental association of sedentary time with mortality. Overall, at least a median of 6 min/day of vigorous physical activity, 30 min/day of MVPA, 64 min/day of moderate physical activity, or 163 min/day of light physical activity (mutually-adjusted for other intensities) attenuated the association between sedentary time and mortality. High sedentary time was associated with higher risk of CVD mortality only among participants with low MVPA (HR 1.96; 95% CI 1.23 to 3.14)., Conclusions: Different amounts of each physical activity intensity may attenuate the association between high sedentary time and mortality., (© 2024. The Author(s).)

Background: Our aim was to examine the prospective dose-response associations of American Heart Association's (AHA) LIFE's Essential 8 (LE8) score and number of cardiovascular health (CVH) factors with high score with all-cause and cardiovascular disease (CVD) related mortality., Methods: We pooled 6 consecutive waves of the National Health and Nutrition Examination Survey (NHANES) comprising rounds between 2007 and 2008 and 2017-2018. We calculated hazard ratios (HRs) and conducted restricted cubic splines models to assess the dose-response association of LE8 score and CVH factors with all-cause and CVD mortality., Results: Analyses included 23,531 adults aged 18 years and over (mean [SD] age, 43.6 [16.7] years; 11,979 [51%] female; 8960 [38.1%] non-Hispanic white individuals) with a median follow-up of 7.3 years (IQR 4.3-10.1), corresponding to 168,033 person-years. The dose-response analyses showed a significant inverse curvilinear trend for the association between LE8 score with all-cause and CVD mortality. The optimal risk reduction for all-cause mortality was found at 100 points of the LE8 Score (HR, 0.50; 95% CI, 0.27-0.93) compared to the reference (median LE8 score [62.5 points]). Moreover, the dose-response association between LE8 and CVD mortality also exhibited a significant inverse curvilinear association up to 90 points (HR, 0.41; 95% CI, 0.17-0.99). Optimal levels of LE8 score may be able to avert around 40% of the annual all-cause and CVD deaths among the US adult population., Conclusions: Best-case scenario of CVH may reduce around 40% of the all-cause and CVD annual mortality among adults in the United States., Competing Interests: Declaration of competing interest None., (Copyright © 2024. Published by Elsevier Inc.)

Objectives: This study aims to examine the associations of daily step count with all-cause mortality and incident cardiovascular disease (CVD) by sedentary time levels and to determine if the minimal and optimal number of daily steps is modified by high sedentary time., Methods: Using data from the UK Biobank, this was a prospective dose-response analysis of total daily steps across low (<10.5 hours/day) and high (≥10.5 hours/day) sedentary time (as defined by the inflection point of the adjusted absolute risk of sedentary time with the two outcomes). Mortality and incident CVD was ascertained through 31 October 2021., Results: Among 72 174 participants (age=61.1±7.8 years), 1633 deaths and 6190 CVD events occurred over 6.9 (±0.8) years of follow-up. Compared with the referent 2200 steps/day (5th percentile), the optimal dose (nadir of the curve) for all-cause mortality ranged between 9000 and 10 500 steps/day for high (HR (95% CI)=0.61 (0.51 to 0.73)) and low (0.69 (0.52 to 0.92)) sedentary time. For incident CVD, there was a subtle gradient of association by sedentary time level with the lowest risk observed at approximately 9700 steps/day for high (0.79 (0.72 to 0.86)) and low (0.71 (0.61 to 0.83)) sedentary time. The minimal dose (steps/day associated with 50% of the optimal dose) of daily steps was between 4000 and 4500 steps/day across sedentary time groups for all-cause mortality and incident CVD., Conclusions: Any amount of daily steps above the referent 2200 steps/day was associated with lower mortality and incident CVD risk, for low and high sedentary time. Accruing 9000-10 500 steps/day was associated with the lowest mortality risk independent of sedentary time. For a roughly equivalent number of steps/day, the risk of incident CVD was lower for low sedentary time compared with high sedentary time., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY. Published by BMJ.)

Cardiovascular health (CVH) is a critical issue for global health. However, no previous study has determined the prevalence of cardiovascular risk factors based on the American Heart Association's (AHA) Life's Essential 8 (LE8). Therefore, we aimed to estimate the global prevalence of the eight cardiovascular risk factors identified in the LE8. A systematic search of systematic reviews with meta-analysis on cardiovascular risk factors covering data reported between 2000 and 2019 was conducted on PubMed, Epistemonikos, and the Cochrane Library until 1 May 2023. After applying exclusion criteria, 79 studies remained in the final selection for the narrative synthesis in the systematic review, of which 33 of them were used in the meta-analysis which included 2 555 639 participants from 104 countries. The overall pooled prevalence of cardiovascular risk factors was as follows: insufficient physical activity, 26.3% (95% CI 2.3%-63.4%), no adherence to a healthy diet, 34.1% (95% CI 5.8%-71.2%), nicotine exposure, 15.4% (95% CI 10.4%-21.2%), insufficient sleep quality, 38.5% (95% CI 14.0%-66.7%), obesity, 17.3% (95% CI 6.1%-32.6%), dyslipidemia, 34.1% (95% CI 33.8%-34.4%), diabetes, 12.0% (95% CI 7.0%-18.2%), and hypertension, 29.4% (95% CI 23.3%-35.8%). These results warrant prevention strategies aimed at reducing insufficient sleep quality, and no adherence to a healthy diet as leading cardiovascular risk factors worldwide. The high prevalence of hypertension among children and adults is concerning and should also be adequately addressed through global policies., Competing Interests: Conflict of interest: None declared., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objective: To examine the joint associations between physical activity and abdominal obesity with the risk of cardiovascular disease (CVD) events., Methods: We included 70 830 UK Biobank participants (mean age±SD=61.6 ± 7.9 years; 56.4% women) with physical activity measured by wrist-worn accelerometers and without major chronic diseases. Participants were jointly categorised into six groups based on their physical activity level (tertiles of total volume and specific intensity levels) and presence or absence of abdominal obesity based on measured waist circumference. Associations with incident CVD (fatal and non-fatal events) were determined using proportional subdistribution hazard models with multivariable adjustment., Results: After excluding events during the first 2 years of follow-up, participants were followed for a median of 6.8 years, during which 2795 CVD events were recorded. Compared with the low abdominal adiposity and highest tertile of physical activity, abdominal obesity was associated with higher risk of incident CVD, especially in those with low levels of vigorous-intensity physical activity (HR 1.42, 95% CI 1.22 to 1.64). Approximately 500 min per week of moderate-to-vigorous intensity and approximately 30-35 min of vigorous-intensity physical activity offset the association of abdominal obesity and the risk of having a CVD event., Conclusion: Physical activity equivalent to approximately 30-35 min of vigorous intensity per week appears to offset the association between abdominal obesity and incident CVD. About 15 times more physical activity of at least moderate intensity is needed to achieve similar results., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: There is little knowledge on the dose-response association between cardiovascular health (CVH) and risk of all-cause, cardiovascular disease (CVD) and cancer deaths among cancer survivors., Aims: We aimed to examine the dose-response association of CVH with all-cause, CVD, and cancer mortality., Methods: A total of 1701 US adult cancer survivors were followed-up during a median of 7.3 (IQR 4.0-10.2) years from 2007 to 2018 through the National Health and Nutrition Examination Survey (NHANES). We used the American Heart Association´s (AHA) Life´s Essential 8 (LE8) as a proxy for CVH., Results: Restricted cubic spline models indicated a close to inverse linear shape for the dose-response association between LE8 score and all-cause mortality with significant risk reductions within the range between 61.25 (Hazard ratio [HR]: 0.76, 95% CI, 0.59-0.98) and 100 points (HR: 0.28, 95%CI, 0.12-0.62), and a curvilinear shape for the dose-response association between LE8 score and CVD deaths with significant risk reductions within the range between 50.25 (HR: 0.72, 95% CI, 0.52-0.99) and 90.25 points (HR: 0.15, 95%CI, 0.02-0.98). No significant dose-response association was observed between LE8 and cancer deaths., Conclusions: Our study showed a close to inverse relationship between higher LE8 and risk of death from all cause, an inverse curvilinear relationship between higher LE8 and the risk for CVD death, and a non-significant association between higher LE8 and the risk of cancer death among US adult cancer survivors, which may translate to a substantial number of annual averted deaths and thus important public health implications., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Importance: Studies examining the associations of different combinations of intensity-specific aerobic and muscle strengthening activity (MSA) with all-cause and cause-specific mortality are scarce; the few available estimates are disparate., Objective: To examine the prospective associations of different combinations of moderate aerobic physical activity (MPA), vigorous aerobic physical activity (VPA), and MSA with all-cause, cardiovascular (CVD), and cancer mortality., Design, Setting, and Participants: This nationwide prospective cohort study used data from the US National Health Interview Survey. A total of 500 705 eligible US adults were included in the study and followed up during a median of 10.0 years (5.6 million person-years) from 1997 to 2018. Data were analyzed from September 1 to September 30, 2022., Exposures: Self-reported cumulative bouts (75 weekly minutes) of MPA and VPA with recommended MSA guidelines (yes or no) to obtain 48 mutually exclusive exposure categories., Main Outcomes and Measures: All-cause, CVD, and cancer mortality. Participants were linked to the National Death Index through December 31, 2019., Results: Overall, 500 705 participants (mean [SD] age, 46.4 [17.3] years; 210 803 [58%] female; 277 504 [77%] White) were included in the study. Compared with the reference group (doing no MPA or VPA and less than recommended MSA), the category associated with the lowest hazard ratio (HR) for all-cause mortality was more than 0 to 75 minutes of MPA combined with more than 150 minutes of VPA and 2 or more MSA sessions per week (HR, 0.50; 95% CI, 0.42-0.59). The optimal combinations for CVD and cancer mortality risk reduction were more than 150 to 225 minutes of MPA, more than 0 to 75 minutes of VPA, and 2 or more MSA sessions per week (HR, 0.30; 95% CI, 0.15-0.57), and more than 300 minutes of MPA, more than 0 to 75 minutes of VPA, and 2 or more MSA sessions per week (HR, 0.44; 95% CI, 0.23-0.82), respectively. Adjusted mortality rates represented an approximately 50% lower mortality rate for all-cause and cancer mortality and an approximately 3-fold lower mortality rate for CVD mortality., Conclusions and Relevance: This cohort study demonstrated that balanced levels of MPA, VPA, and MSA combined may be associated with optimal reductions of mortality risk. Higher-than-recommended levels of MPA and VPA may further lower the risk of cancer and all-cause mortality, respectively.

Background: The complexity of sleep hinders the formulation of sleep guidelines. Recent studies suggest that different unhealthy sleep characteristics jointly increase the risks for cardiovascular disease (CVD). This study aimed to estimate the differences in CVD-free life expectancy between people with different sleep profiles., Methods: We included 308,683 middle-aged adults from the UK Biobank among whom 140,181 had primary care data linkage. We used an established composite sleep score comprising self-reported chronotype, duration, insomnia complaints, snoring, and daytime sleepiness to derive three sleep categories: poor, intermediate, and healthy. We also identified three clinical sleep disorders captured by primary care and inpatient records within 2 years before enrollment in the cohort: insomnia, sleep-related breathing disorders, and other sleep disorders. We estimated sex-specific CVD-free life expectancy with three-state Markov models conditioning on survival at age 40 across different sleep profiles and clinical disorders., Results: We observed a gradual loss in CVD-free life expectancy toward poor sleep such as, compared with healthy sleepers, poor sleepers lost 1.80 [95% CI 0.96-2.75] and 2.31 [1.46-3.29] CVD-free years in females and males, respectively, while intermediate sleepers lost 0.48 [0.41-0.55] and 0.55 [0.49-0.61] years. Among men, those with clinical insomnia or sleep-related breathing disorders lost CVD-free life by 3.84 [0.61-8.59] or 6.73 [5.31-8.48] years, respectively. Among women, sleep-related breathing disorders or other sleep disorders were associated with 7.32 [5.33-10.34] or 1.43 [0.20-3.29] years lost, respectively., Conclusions: Both self-reported and doctor-diagnosed poor sleep are negatively associated with CVD-free life, especially pronounced in participants with sleep-related breathing disorders., (© 2023. The Author(s).)

Background: While handgrip strength is associated with all-cause and cause-specific mortality, whether such associations are dose-dependent is largely unknown. Therefore, we conducted a systematic review on the dose-response relationship of handgrip strength with all-cause mortality, cancer, and cardiovascular mortality., Methods: The data source included three electronic databases (PubMed/MEDLINE, Web of Science and Scopus) from inception to 8 February 2022. Prospective cohort studies of healthy adults with objective measures of handgrip strength were included. Two researchers independently screened studies, extracted data, and assessed risk of bias. We used estimates regarding handgrip strength categories to conduct a random forest model, and a two-stage random-effects hierarchical meta-regression model pooling study-specific estimates for dose-response relationship. Outcomes included all-cause, cancer, and cardiovascular mortality., Reults: Forty-eight studies comprising 3,135,473 participants (49.6% women, age range 35-85 years) were included. Random forest models showed a significant inverse association between handgrip strength and all-cause and cause-specific mortality. Dose-response meta-analyses showed that higher levels of handgrip strength significantly reduced the risk of all-cause mortality within 26-50 kg (Higgin´s I 2 =45.7%) in a close-to-linear inverse fashion. Cancer and cardiovascular mortality displayed a trend towards a U-shaped association with a significant risk reduction between 16 and 33 kg (Higgin´s I 2 =77.4%), and a close-to-linear inverse shaped and significant risk reduction ranging from 24 to 40 kg (Higgin´s I 2 =79.7%) respectively., Conclusion: There is strong evidence for an association between lower handgrip strength with higher all-cause, cancer, and cardiovascular mortality risk. The dose-response relationship of handgrip strength substantially varies depending on the cause of mortality., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Importance: Recommendations for the number of steps per day may be easier to enact for some people than the current time- and intensity-based physical activity guidelines, but the evidence to support steps-based goals is limited., Objective: To describe the associations of step count and intensity with all-cause mortality and cancer and cardiovascular disease (CVD) incidence and mortality., Design, Setting, and Participants: This population-based prospective cohort study used data from the UK Biobank for 2013 to 2015 (median follow-up, 7 years) and included adults 40 to 79 years old in England, Scotland, and Wales. Participants were invited by email to partake in an accelerometer study. Registry-based morbidity and mortality were ascertained through October 2021. Data analyses were performed during March 2022., Exposures: Baseline wrist accelerometer-measured daily step count and established cadence-based step intensity measures (steps/min): incidental steps, (<40 steps/min), purposeful steps (≥40 steps/min); and peak-30 cadence (average steps/min for the 30 highest, but not necessarily consecutive, min/d)., Main Outcomes and Measures: All-cause mortality and primary and secondary CVD or cancer mortality and incidence diagnosis. For cancer, analyses were restricted to a composite cancer outcome of 13 sites that have a known association with reduced physical activity. Cox restricted cubic spline regression models were used to assess the dose-response associations. The linear mean rate of change (MRC) in the log-relative hazard ratio for each outcome per 2000 daily step increments were also estimated., Results: The study population of 78 500 individuals (mean [SD] age, 61 [8] years; 43 418 [55%] females; 75 874 [97%] White individuals) was followed for a median of 7 years during which 1325 participants died of cancer and 664 of CVD (total deaths 2179). There were 10 245 incident CVD events and 2813 cancer incident events during the observation period. More daily steps were associated with a lower risk of all-cause (MRC, -0.08; 95% CI, -0.11 to -0.06), CVD (MRC, -0.10; 95% CI, -0.15 to -0.06), and cancer mortality (MRC, 95% CI, -0.11; -0.15 to -0.06) for up to approximately 10 000 steps. Similarly, accruing more daily steps was associated with lower incident disease. Peak-30 cadence was consistently associated with lower risks across all outcomes, beyond the benefit of total daily steps., Conclusions and Relevance: The findings of this population-based prospective cohort study of 78 500 individuals suggest that up to 10 000 steps per day may be associated with a lower risk of mortality and cancer and CVD incidence. Steps performed at a higher cadence may be associated with additional risk reduction, particularly for incident disease.

Background: The relationship between joint changes in physical activity and adiposity with mortality is not well understood. We examined the association of changes in these two established risk factors with all-cause (ACM), cardiovascular disease (CVD), and cancer mortality., Methods: We used longitudinal data from Taiwan's MJ Cohort, comprising 116,228 general population adults recruited from 1998-2013 with repeated measures 4.6 y (2.5) apart and followed up for mortality for 11.9 y (3.5). Physical activity, body mass index (BMI), waist circumference (WC), and body fat percentage (BF%) groups and changes were based on public health and clinical guidelines., Results: Compared to stable-insufficient physical activity, increasing physical activity from any baseline level was associated with lower ACM (HR [95%CI]): 0.85 [0.74, 0.96]) and CVD mortality (0.72 [0.55, 0.93]) risk. This was approximately equal to meeting physical activity guidelines at both timepoints (eg: 0.71 [0.58, 0.88] for CVD mortality). Compared to stable-overweight/moderate adiposity, decreasing adiposity level attenuated but did not offset mortality risk for all three outcomes (eg: BMI = 0.95 [0.76, 1.16] for CVD mortality). Only maintaining a healthy adiposity level at both timepoints offset mortality risk (BMI = 0.75 [0.61, 0.89]) for CVD mortality). In the joint changes analyses, lower mortality risk was a consequence of increases in physical activity across adiposity change groups (eg: WC decrease = 0.57 [0.48, 0.67]; WC stability = 0.73 [0.66, 0.80], WC increase = 0.83 [0.72, 0.97] for ACM). Decreasing adiposity attenuated the negative associations of decreased physical activity (BF% = 1.13 [0.95, 1.35] for ACM)., Conclusions: We found a lower risk for ACM, CVD, and cancer mortality from increasing physical activity and an attenuation from decreasing adiposity regardless of baseline levels. The beneficial associations of joint changes were primarily driven by physical activity, suggesting lower mortality risk may be more immediate through physical activity improvements compared to adiposity improvements alone., (© 2022. The Author(s).)

Background Despite the well-established capacity of physical activity to reduce blood pressure, the associations between physical activity with cardiovascular disease (CVD) incidence and mortality in people living with hypertension are not well understood. We examine the dose-response associations of device-assessed physical activity with all-cause and CVD mortality and CVD incidence (total, stroke, and coronary heart disease) in adults with hypertension. Methods and Results This prospective study included data from 39 294 participants with hypertension in the UK Biobank study who had valid accelerometry data and for whom mortality and CVD followed-up data were available. We categorized moderate-to-vigorous physical activity and total physical activity volume into 4 categories based on the 10th, 50th, and 90th percentiles and used Cox regressions to estimate their associations with CVD mortality and incidence outcomes. Splines were used to assess the dose-response associations. During a median follow-up of 6.25 years (241 418 person-years), 1518 deaths (549 attributable to CVD) and 4933 CVD (fatal and nonfatal) incident events were registered. Compared with the lowest category of moderate-to-vigorous physical activity, the relative risks (hazard ratios and 95% CIs) of all-cause mortality for increasing categories were 0.53 (0.46-0.61), 0.41 (0.34-0.49), and 0.36 (0.26-0.49). We found associations of similar magnitude for total CVD incidence, stroke, and coronary heart disease; and for total physical activity volume across all outcomes. For all outcomes, there were linear or nearly linear inverse dose-response relationships with no evidence of harms with high levels of physical activity. Results were robust to removing participants who died within the first 2 years. Conclusions Our findings underscore the importance of physical activity for people living with hypertension and provide novel insights to support the development of physical activity guideline recommendations for this high-risk group.

The present systematic review with meta-analysis sought to estimate the accuracy of different waist-to-height ratio (WHtR) cutoff ranges as risk indicators for cardiometabolic health in different populations of children and adolescents. Systematic searches were undertaken to identify studies in apparently healthy participants aged 3-18 years that conducted receiver operating characteristic curve analysis and reported area under the receiver operating characteristic curves for WHtR with any cardiometabolic biomarker. Forty-one cross-sectional studies were included in the meta-analysis, including 138,561 young individuals (50% girls). Higher area under summary receiver operating characteristic (AUSROC) values were observed in cutoffs between 0.46 and 0.50 (AUSROC = 0.83, 95%CI: 0.80-0.86) and ≥0.51 (AUSROC = 0.87, 95%CI: 0.84-0.90) (p < 0.001 in comparison with cutoffs 0.41 to 0.45), with similar results in both sexes. The AUSROC value increased in the East and Southeast Asian regions using a WHtR cutoff of ≥0.46 (AUSROC = 0.90, 95%CI: 0.87 to 0.92). A cutoff of ≥0.54 was optimal for the Latin American region (AUSROC = 0.96, 95%CI: 0.94-0.97). Our meta-analysis identified optimal cutoff values of WHtR for use in children and adolescents from different regions. Despite the widely accepted WHtR cutoff of 0.50, the present study indicated that a single cutoff value of WHtR may be inappropriate., (© 2021 World Obesity Federation.)

Context: The aim was to summarize estimates of the potential benefits for cardiometabolic risk markers and all-cause mortality of replacing time spent in sedentary behaviors with light-intensity physical activity or with moderate to vigorous physical activity, from studies using device-based measurement., Evidence Acquisition: Four databases covering the period up to December 2016 were searched and analyzed (February 2017). Data were extracted by two independent reviewers. For the meta-analyses, the estimated regression coefficients (β) and 95% CIs were analyzed for BMI, waist circumference, and high-density lipoprotein cholesterol. Pooled relative rate and 95% CIs were calculated for fasting glucose, fasting insulin, and homeostatic model assessment-insulin resistance values. Hazard ratios were extracted from studies of all-cause mortality risk., Evidence Synthesis: Ten studies (with 17,390 participants) met the inclusion criteria. Reallocation of 30 minutes of sedentary time to light-intensity physical activity was associated with reductions in waist circumference, fasting insulin, and all-cause mortality risk; and with an increase in high-density lipoprotein cholesterol. Reallocating 30 minutes of sedentary time to moderate to vigorous physical activity was associated with reductions in BMI, waist circumference, fasting glucose, fasting insulin, and all-cause mortality (not pooled) and with an increase in high-density lipoprotein cholesterol., Conclusions: Replacing sedentary time with either light-intensity physical activity or moderate to vigorous physical activity may be beneficial, but when sedentary time is replaced with moderate to vigorous physical activity, the predicted impacts are stronger and apparent for a broader range of risk markers. These findings point to potential benefits of replacing sedentary time with light-intensity physical activity, which may benefit those less able to tolerate or accommodate higher-intensity activities, including many older adults., (Copyright © 2018. Published by Elsevier Inc.)

Background: There is little evidence of whether or not those who have attended cardiac rehabilitation (CR) are meeting the physical activity guidelines recommended for secondary prevention of cardiovascular disease. In healthy individuals, there is evidence, that even if individuals are meeting the physical activity guidelines, the harmfulness of too much sedentary behaviour remains (active couch potato (ACP) phenomenon). Currently, there appears to be no evidence of the ACP phenomenon in those attending CR. The aims of the study are to examine the level of physical activity and sedentary behaviour in those with coronary heart disease (CHD) who have attended CR, and to investigate the potential independent associations between these behaviours and cardio-metabolic health, health-related quality of life, exercise capacity, anxiety and depression., Methods: A prospective cohort study will be conducted in Australia over 12-months. Baseline data from this study will contribute to an international, multi-centre cross-sectional study (Australia, New Zealand, United States of America, South Africa, Spain, and Portugal). Adults currently enrolled in a 6-week phase II cardiac rehabilitation program with stable CHD and receiving optimal medical treatment +/- revascularisation will be recruited. Outcome measures will be taken at baseline (commence CR), 6 weeks (complete CR), 6 and 12-months. Physical activity and sedentary behaviour will be measured using accelerometry and two questionnaires (Active Australia Survey, Past-Day Adults' Sedentary Time questionnaire). Health outcomes will include body mass index, waist-to-hip ratio, lipid profile, blood glucose level, quality-of-life (MacNew), exercise capacity (6-min walk test), anxiety and depression (Hospital Anxiety and Depression Scale)., Discussion: There has been limited investigation of the physical activity levels and sedentary behaviour of individuals with CHD attending CR. There are no studies assessing the relationship of these behaviours with health outcomes over the short and medium-term. As in healthy individuals, physical activity and sedentary behaviour may have independent effects on cardiovascular risk factors in people with CHD, which may contribute to recurrent cardiovascular events. If this is so, reducing sedentary behaviour may be a feasible first-line, additional and more achievable strategy to improve the health of those with CHD, alongside traditional recommendations to increase the time spent in moderate-to-vigorous intensity physical activity., Trial Registration: Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12615000995572.