Brief bouts of device-measured intermittent lifestyle physical activity and its association with major adverse cardiovascular events and mortality in people who do not exercise: a prospective cohort study

Device-measured vigorous intermittent lifestyle physical activity (VILPA) and major adverse cardiovascular events: evidence of sex differences

BACKGROUND

Vigorous intermittent lifestyle physical activity (VILPA) refers to brief bouts of intense physical activity embedded into daily life.

OBJECTIVE

To examine sex differences in the dose-response association of VILPA with major adverse cardiovascular events (MACE) and its subtypes.

METHODS

Using multivariable-adjusted cubic splines, we examined the associations of daily VILPA duration with overall MACE and its subtypes (incident myocardial infarction, heart failure and stroke) among non-exercisers (individuals self-reporting no leisure-time exercise and no more than one recreational walk per week) in the UK Biobank. We also undertook analogous analyses for vigorous physical activity among exercisers (individuals self-reporting participation in leisure-time exercise and/or recreational walking more than once a week).

RESULTS

Among 13 018 women and 9350 men, there were 331 and 488 all MACE, respectively, over a 7.9-year follow-up. In women, daily VILPA duration exhibited a near-linear dose-response association with all MACE, myocardial infarction and heart failure. In men, dose-reponse curves were less clear with less evidence of statistical signifigance. Compared with women with no VILPA, women's median daily VILPA duration of 3.4 min was associated with hazard ratios (HRs; 95% confidence intervals) of 0.55 (0.41 to 0.75) for all MACE and 0.33 (0.18 to 0.59) for heart failure. Women's minimum doses of 1.2-1.6 min of VILPA per day were associated with HRs of 0.70 (0.58 to 0.86) for all MACE, 0.67 (0.50 to 0.91) for myocardial infarction, and 0.60 (0.45 to 0.81) for heart failure. The equivalent analyses in UK Biobank's accelerometry sub-study exercisers suggested no appreciable sex differences in dose-response.

CONCLUSIONS

Among non-exercising women, small amounts of VILPA were associated with a substantially lower risk of all MACE, myocardial infarction and heart failure. VILPA may be a promising physical activity target for cardiovascular disease prevention, particularly in women unable or not willing to engage in formal exercise.

Device-measured stationary behaviour and cardiovascular and orthostatic circulatory disease incidence

BACKGROUND

Previous studies have indicated that standing may be beneficially associated with surrogate metabolic markers, whereas more time spent sitting has an adverse association. Studies assessing the dose-response associations of standing, sitting and composite stationary behaviour time with cardiovascular disease (CVD) and orthostatic circulatory disease are scarce and show an unclear picture.

OBJECTIVE

To examine associations of daily sitting, standing and stationary time with CVD and orthostatic circulatory disease incidence.

METHODS

We used accelerometer data from 83 013 adults (mean age ± standard deviation = 61.3 ± 7.8; female = 55.6%) from the UK Biobank to assess daily time spent sitting and standing. Major CVD was defined as coronary heart disease, heart failure and stroke. Orthostatic circulatory disease was defined as orthostatic hypotension, varicose vein, chronic venous insufficiency and venous ulcers. To estimate the dose-response hazard ratios (HR) we used Cox proportional hazards regression models and restricted cubic splines. The Fine-Gray subdistribution method was used to account for competing risks.

RESULTS

During 6.9 (±0.9) years of follow-up, 6829 CVD and 2042 orthostatic circulatory disease events occurred. When stationary time exceeded 12 h/day, orthostatic circulatory disease risk was higher by an average HR (95% confidence interval) of 0.22 (0.16, 0.29) per hour. Every additional hour above 10 h/day of sitting was associated with a 0.26 (0.18, 0.36) higher risk. Standing more than 2 h/day was associated with an 0.11 (0.05, 0.18) higher risk for every additional 30 min/day. For major CVD, when stationary time exceeded 12 h/day, risk was higher by an average of 0.13 (0.10, 0.16) per hour. Sitting time was associated with a 0.15 (0.11, 0.19) higher risk per extra hour. Time spent standing was not associated with major CVD risk.

CONCLUSIONS

Time spent standing was not associated with CVD risk but was associated with higher orthostatic circulatory disease risk. Time spent sitting above 10 h/day was associated with both higher orthostatic circulatory disease and major CVD risk. The deleterious associations of overall stationary time were primarily driven by sitting. Collectively, our findings indicate increasing standing time as a prescription may not lower major CVD risk and may lead to higher orthostatic circulatory disease risk.

Can incidental physical activity offset the deleterious associations of sedentary behaviour with major adverse cardiovascular events?

AIMS

Incidental physical activity as part of daily living may offer feasibility advantages over traditional exercise. We examined the joint associations of incidental physical activity and sedentary behaviour with major adverse cardiovascular events (MACE) risk.

METHODS

Analyses included 22,368 non-exercising adults from the UK Biobank accelerometry sub-study (Median age [IQR]: 62.9 [11.6] years; 41.8% male). Physical activity and sedentary behaviour exposures were derived using a machine learning-based intensity and posture classification schema. We assessed the tertile-based joint associations of sedentary behaviour and: a) incidental vigorous (VPA), b) incidental moderate to vigorous (MVPA), c) vigorous intermittent lifestyle physical activity (VILPA; bouts lasting up to 1 minute), and d) moderate to vigorous intermittent lifestyle physical activity (MV-ILPA; bouts lasting up to 3 minutes) with MACE risk.

RESULTS

Over an 8.0-year median follow-up, 819 MACE events occurred. Compared to the highest physical activity and lowest sedentary time, high sedentary behaviour (>11.4 hours/day) with low incidental VPA (<2.1 minutes/day) had an HR of 1.34 (95% CI: 0.98, 1.84) and low incidental MVPA (<21.8 minutes/day) had a 1.89 HR (95% CI: 1.42, 2.52) for MACE. Sedentary behaviour was not associated with MACE at medium and high levels of VPA or VILPA. Completing 4.1 minutes/day of VPA or VILPA may offset the MACE risk associated with high sedentary behaviour. Conversely, 31-65 minutes of incidental MVPA or 26-52 minutes of MV-ILPA per day largely attenuated the associations with MACE.

CONCLUSION

Brief intermittent bursts of vigorous incidental physical activity may offset cardiovascular risks from high sedentary behaviour.

Sedentarism and Chronic Health Problems

Increased mechanization and technological advances have simplified our lives on the one hand and increased sedentary behaviors on the other hand, paving the way for emerging global health concerns, i.e., sedentarism, which could be the leading cause of all major chronic health problems worldwide. Sedentarism is a habitual behavior of choosing and indulging in low-energy expenditure activities (≤1.5 metabolic equivalents), such as chairtype (sitting, studying, traveling) or screen-type activities (TV, computers, mobile). With technological advancements, there is a significant transition in the lifestyles of people from being active (walking) to being more deskbound (sitting). Prolonged sitting can have unintended consequences for health with sitting time >7 h/d, leading to a 5% increase in all-cause mortality with each additional hour spent sitting (i.e., +7 h/d), while considering physical activity levels. This review will highlight how sedentarism is emerging as a major risk factor for the rising incidence of non-communicable diseases, especially among young adults and adults. Chronic diseases, such as obesity, diabetes, coronary heart disease, and cancer, are the leading causes of death worldwide. Hence, there is an urgent need for collective action to mitigate the burgeoning public health crisis posed by sedentarism in the 21st century. This paper intends to set in motion a call for all policymakers and public health professionals placed nationally or internationally to reach a consensus on ending sedentarism and provide viable resolutions for effective management of excessive sedentary behaviors and healthy adoption and maintenance of active lifestyles among individuals of all age groups.

Accelerometer-measured physical activity, sedentary behavior, and incidence of macrovascular and microvascular events in individuals with type 2 diabetes mellitus and prediabetes

BACKGROUND

Physical activity (PA) is considered beneficial for lowering cardiovascular risks following type 2 diabetes mellitus (T2DM) and prediabetes, but existing evidence relies mainly on self-reported measurements. We aimed to describe the intensity-specific dose-response associations of PA and sedentary behavior (SB) with macrovascular and microvascular events among individuals with T2DM and prediabetes.

METHODS

This study included 11,474 individuals with T2DM and prediabetes from the UK Biobank. PA, including total PA, moderate-to-vigorous intensity PA (MVPA), light intensity PA (LPA), and SB, were measured by accelerometers over 7 days. MVPA was categorized according to the American Diabetes Association guideline-recommended level (at least 150 min/week), and total PA, LPA, and SB were grouped by tertiles. The outcomes were incidences of macrovascular events, microvascular events, heart failure (HF), and their combination (composite events). The events were ascertained using the ICD-10 codes on the hospital or death records.

RESULTS

During a median follow-up of 6.8 years, 1680 cases were documented, including 969 macrovascular events, 839 microvascular events, and 284 incidents of HF. Accelerometer-measured PA, irrespective of intensity, was inversely associated with the risk of composite events and each outcome in the dose-response patterns. Regarding categorized PA, engagement in total PA (high vs. low) was associated with decreased risk of macrovascular events (hazard ratio (HR) = 0.80; 95% confidence interval (95%CI): 0.67-0.95), microvascular events (HR = 0.76; 95%CI: 0.63-0.93), and HF (HR = 0.46; 95%CI: 0.32-0.66). Adherence to MVPA, but not LPA, above the guideline-recommended level (at least 150 min/week) was associated with reduced risk of macrovascular events (HR = 0.80; 95%CI: 0.68-0.95), microvascular events (HR = 0.76; 95%CI: 0.63-0.92), and HF (HR = 0.65; 95%CI: 0.46-0.92). The minimum dose of MVPA for lowering the risk of composite events was approximately 59.0 min/week. More time spent in SB was associated with an increased risk of composite events (high vs. low, HR = 1.17; 95%CI: 1.02-1.35) and HF (high vs. low, HR = 1.54; 95%CI: 1.09-2.20). Replacement of 30 min of SB (HR = 0.73; 95%CI: 0.65-0.81) and LPA (HR = 0.74; 95%CI: 0.66-0.83) with MVPA dramatically reduced the risk of composite events.

CONCLUSION

Adherence to a higher amount of accelerometer-measured PA, especially MVPA at least 59 min/week, is associated with reduced risks of macrovascular and microvascular events among individuals with T2DM and prediabetes. Replacement of SB and LPA with MVPA helped lower the risk of diabetic vascular events.

Promoting vigorous intermittent lifestyle physical activity (vilpa) in middle-aged adults: an evaluation of the movsnax mobile app

BACKGROUND

Most adults fail to meet the moderate to vigorous physical activity-based recommendations needed to maintain or improve health. Vigorous Intermittent Lifestyle Physical Activity (VILPA) refers to short (1-2 min) high-intensity activities that are integrated into activities of daily living. VILPA has shown strong potential to improve health and addresses commonly reported barriers to physical activity. However, it is unknown how VILPA can best be promoted among the adult population. This study aimed to evaluate the usability, user engagement, and satisfaction of a mobile application (MovSnax) designed to promote VILPA.

METHODS

A concurrent mixed methods design was used. It comprised four parts. Part A was a survey with n = 8 mHealth and physical activity experts who had used the app over 7-10 days. Part B was think-aloud interviews with n = 5 end-users aged 40-65 years old. Part C was a survey with a new group of 40-65-year-old end-users (n = 35) who had used the MovSnax app over 7-10 days. Part D was semi-structured interviews with n = 18 participants who took part in Part C. Directed content analysis was used to analyze the results from Parts A, B, and D, and descriptive statistics were used to analyze findings from Part C.

RESULTS

Participants reported positive views on the MovSnax app for promoting VILPA but also identified usability issues such as unclear purpose, difficulties in manual data entry, and limited customization options. Across the different data collections, they consistently emphasized the need for more motivational features, clearer feedback, and gamification elements to enhance engagement. Quantitative assessment showed satisfactory scores on objective measures but lower ratings on subjective aspects, possibly due to unfamiliarity with the VILPA concept and/or technical barriers.

CONCLUSIONS

The MovSnax app, tested in the present study, is the world's first digital tool aimed specifically at increasing VILPA. The findings of the present study underscore the need for further app refinement, focusing on clarifying its purpose and instructions, boosting user engagement through personalization and added motivational elements, enhancing accuracy in detecting VILPA bouts, implementing clearer feedback mechanisms, expanding customization choices (such as font size and comparative data), and ensuring transparent and meaningful activity tracking.

Intensity-specific physical activity measured by accelerometer and the risk of mortality among individuals with cardiometabolic diseases: A prospective study from the UK Biobank

BACKGROUND

While the health benefits of physical activity for general population are well-recognized, the prospective associations of physical activity volume and intensity with mortality among cardiometabolic disease individuals remain unclear.

OBJECTIVE

The objective of this study was to investigate the associations of accelerometer-measured intensity-specific physical activity with mortality risk among population with cardiometabolic disease.

DESIGN

Prospective cohort study.

SETTING

Participants were recruited from the United Kingdom (UK) across 22 assessment centers from 2006 to 2010.

PARTICIPANTS

A total of 9524 participants from the UK Biobank (median: 67.00 years, interquartile range: 61.00-70.00 years) were included in final study.

METHODS

Accelerometer-measured total volume, moderate-to-vigorous and light intensity physical activity collecting from 2013 to 2015 were quantified using a machine learning model. Multivariable restricted cubic splines and Cox proportional hazard models with hazard ratios (HRs) and 95 % confidence intervals (CIs) were employed to examine the associations of interests.

RESULTS

During the follow-up period (median: 6.87 years; interquartile range: 6.32-7.39 years), there were 659 (6.92 %) death events with 218 (2.29 %) cardiovascular disease-related deaths and 441 (4.63 %) non-cardiovascular disease-related deaths separately. In the fully adjusted models, compared with participants in the lowest quartiles of total volume, moderate-to-vigorous and light physical activities, the adjusted HRs (95 % CIs) of all-cause mortality for those in the highest quartiles were 0.40 (0.31, 0.52), 0.48 (0.37, 0.61), and 0.56 (0.44, 0.71) while those for cardiovascular diseases-related mortality were 0.35 (0.22, 0.55), 0.52 (0.35, 0.78) and 0.59 (0.39, 0.88), and for non-cardiovascular diseases-related mortality, they were 0.42 (0.30, 0.59), 0.40 (0.29, 0.54) and 0.54 (0.40, 0.73), separately. The optimal moderate-to-vigorous-intensity physical activity level for cardiovascular diseases-related mortality reduction was found to be in the third quartile (17.75-35.33 min/day). Furthermore, the observed inverse associations were mainly non-linear.

CONCLUSIONS

Promoting physical activity, regardless of intensity, is essential for individuals with cardiometabolic disease to reduce mortality risk. For both all-cause and cardiovascular disease-related and non-cardiovascular disease-related mortality, the observed decrease in risk seems to level off at a moderate level. The current findings deriving from precise device-based physical activity data provide inference for secondary prevention of cardiometabolic disease.

Western diets and chronic diseases

'Westernization', which incorporates industrial, cultural and dietary trends, has paralleled the rise of noncommunicable diseases across the globe. Today, the Western-style diet emerges as a key stimulus for gut microbial vulnerability, chronic inflammation and chronic diseases, affecting mainly the cardiovascular system, systemic metabolism and the gut. Here we review the diet of modern times and evaluate the threat it poses for human health by summarizing recent epidemiological, translational and clinical studies. We discuss the links between diet and disease in the context of obesity and type 2 diabetes, cardiovascular diseases, gut and liver diseases and solid malignancies. We collectively interpret the evidence and its limitations and discuss future challenges and strategies to overcome these. We argue that healthcare professionals and societies must react today to the detrimental effects of the Western diet to bring about sustainable change and improved outcomes in the future.

Revisiting the concept of bout: associations of moderate-to-vigorous physical activity sessions and non-sessions with mortality

INTRODUCTION

Current physical activity guidelines recommend 150 min of moderate-to-vigorous physical activity (MVPA) for health benefits, regardless of the pattern of MVPA. However, MVPA that occurs in sessions (MVPA-S) may have different health implications compared to MVPA that is not accumulated in sessions (MVPA-nonS). This study aimed to investigate the associations of MVPA-S and MVPA-nonS with mortality.

METHODS

We conducted a cohort study of the National Health and Nutrition Examination Survey 2003-2006 (n = 5,658) with accelerometer-measured physical activity at baseline and mortality followed through December 31, 2019. A session was defined as a time window of 30 min or longer where the average intensity was at or above 2020 counts/minute. MVPA accumulated within such sessions was quantified as MVPA-S, while MVPA accumulated outside the sessions was quantified as MVPA-nonS. We examined the joint association of MVPA-S and MVPA-nonS by classifying the participants into four groups (both < 75 min/week [referent], MVPA-S ≥ 75 and MVPA-nonS < 75, MVPA-S < 75 and MVPA-nonS ≥ 75, and both ≥ 75). We used 75 min as the cut-point because it is half of the guideline-recommended MVPA volume where a strong MVPA-mortality association has been observed in previous studies, and because it was close to the median of MVPA-nonS (75 min/week was the 54th percentile), allowing a sufficient sample size in each group for testing statistical significance. The hazard ratios and 95% confidence intervals were estimated with adjustment for important confounders.

RESULTS

During 13.9 years of follow-up (74,988 person-years), there were 1,424 deaths, out of which 472 were related to cardiovascular diseases (CVD). Compared to the referent combination (both < 75), the hazard ratios in the other three combinations were 0.48 (0.33-0.69), 0.85 (0.71-1.01), and 0.45 (0.30-0.67) for all-cause mortality; and were 0.34 (0.17-0.70), 0.96 (0.69-1.33), and 0.40 (0.17-0.90) for CVD mortality, respectively. Results were largely consistent in the spline-based models, age- and sex-stratified analyses, complete-case analysis, competing risk analysis, and the analysis excluding deaths within two years of follow-up.

CONCLUSION

In conclusion, MVPA accumulated in sessions that lasted at least 30 min was associated with significant reductions in all-cause and CVD-specific mortality risks. The health implications of MVPA that were not accumulated in such sessions warrant further investigation.

Occupational physical activity, all-cause, cardiovascular disease, and cancer mortality in 349,248 adults: Prospective and longitudinal analyses of the MJ Cohort

BACKGROUND

Evidence on the health benefits of occupational physical activity (OPA) is inconclusive. We examined the associations of baseline OPA and OPA changes with all-cause, cardiovascular disease (CVD), and cancer mortality and survival times.

METHODS

This study included prospective and longitudinal data from the MJ Cohort, comprising adults over 18 years recruited in 1998-2016, 349,248 adults (177,314 women) with baseline OPA, of whom 105,715 (52,503 women) had 2 OPA measures at 6.3 ± 4.2 years (mean ± SD) apart. Exposures were baseline OPA, OPA changes, and baseline leisure-time physical activity.

RESULTS

Over a mean mortality follow-up of 16.2 ± 5.5 years for men and 16.4 ± 5.4 years for women, 11,696 deaths (2033 of CVD and 4631 of cancer causes) in men and 8980 deaths (1475 of CVD and 3689 of cancer causes) in women occurred. Combined moderately heavy/heavy baseline OPA was beneficially associated with all-cause mortality in men (multivariable-adjusted hazard ratio (HR) = 0.93, 95% confidence interval (95%CI): 0.89-0.98 compared to light OPA) and women (HR = 0.86, 95%CI: 0.79-0.93). Over a mean mortality follow-up of 12.5 ± 4.6 years for men and 12.6 ± 4.6 years for women, OPA decreases in men were detrimentally associated (HR = 1.16, 95%CI: 1.01-1.33) with all-cause mortality, while OPA increases in women were beneficially (HR = 0.83, 95%CI: 0.70-0.97) associated with the same outcome. Baseline or changes in OPA showed no associations with CVD or cancer mortality.

CONCLUSION

Higher baseline OPA was beneficially associated with all-cause mortality risk in both men and women. Our longitudinal OPA analyses partly confirmed the prospective findings, with some discordance between sex groups.

Relationship of device measured physical activity type and posture with cardiometabolic health markers: pooled dose-response associations from the Prospective Physical Activity, Sitting and Sleep Consortium

AIMS/HYPOTHESIS

The aim of this study was to examine the dose-response associations of device-measured physical activity types and postures (sitting and standing time) with cardiometabolic health.

METHODS

We conducted an individual participant harmonised meta-analysis of 12,095 adults (mean ± SD age 54.5±9.6 years; female participants 54.8%) from six cohorts with thigh-worn accelerometry data from the Prospective Physical Activity, Sitting and Sleep (ProPASS) Consortium. Associations of daily walking, stair climbing, running, standing and sitting time with a composite cardiometabolic health score (based on standardised z scores) and individual cardiometabolic markers (BMI, waist circumference, triglycerides, HDL-cholesterol, HbA1c and total cholesterol) were examined cross-sectionally using generalised linear modelling and cubic splines.

RESULTS

We observed more favourable composite cardiometabolic health (i.e. z score <0) with approximately 64 min/day walking (z score [95% CI] -0.14 [-0.25, -0.02]) and 5 min/day stair climbing (-0.14 [-0.24, -0.03]). We observed an equivalent magnitude of association at 2.6 h/day standing. Any amount of running was associated with better composite cardiometabolic health. We did not observe an upper limit to the magnitude of the dose-response associations for any activity type or standing. There was an inverse dose-response association between sitting time and composite cardiometabolic health that became markedly less favourable when daily durations exceeded 12.1 h/day. Associations for sitting time were no longer significant after excluding participants with prevalent CVD or medication use. The dose-response pattern was generally consistent between activity and posture types and individual cardiometabolic health markers.

CONCLUSIONS/INTERPRETATION

In this first activity type-specific analysis of device-based physical activity, ~64 min/day of walking and ~5.0 min/day of stair climbing were associated with a favourable cardiometabolic risk profile. The deleterious associations of sitting time were fully attenuated after exclusion of participants with prevalent CVD and medication use. Our findings on cardiometabolic health and durations of different activities of daily living and posture may guide future interventions involving lifestyle modification.

Moderate intensity intermittent lifestyle physical activity is associated with better executive function in older adults

Executive functions are among the first cognitive abilities to decline with age and age-related executive function slowing predisposes older adults to cognitive disorders and disease. Intermittent Lifestyle Physical Activity (ILPA) reflects brief, unplanned activity that occurs during routine daily activities and is operationalized as activity bouts <60s. Our understanding of short bouts of habitual physical activity and executive functions is limited. We tested the hypothesis that greater amounts of ILPA in moderate and vigorous intensity domains would be associated with better executive function in older adults. Forty older adults (26 females, 68 ± 6, >55 years; body mass index: 26.6 ± 4.3 kg/m2) completed a Trail-Making-Task and wore an activPAL 24-hr/day for 6.2 ± 1.8-days. For each intensity, total time and time spent in bouts <60 s were determined. Trail A (processing speed) and Trail B (cognitive flexibility) were completed in 25.8 ± 8.2 s and 63.2 ± 26.2 s, respectively. Non-parametric Spearman's rank correlations report that moderate ILPA (3.2 ± 3.2 min/day) and total-moderate physical activity (20.1 ± 16.0 min/day) were associated with faster Trail A (total-moderate physical activity: ρ=-0.48; moderate-ILPA: ρ = -0.50; both, p < 0.003) and Trail B time (total-moderate physical activity: ρ = 0.36; moderate-ILPA: ρ = -0.46; both, p < 0.020). However, the results show no evidence of an association with either vigorous physical activity or light physical activity (total time or ILPA bouts: all, p > 0.180). Moderate physical activity accumulated in longer bouts (>60 s) was not associated with Trail B time (p = 0.201). Therefore, more total moderate physical activity and shorter bouts (<60 s) may result in better executive functions in older adults.

Timing of Moderate to Vigorous Physical Activity, Mortality, Cardiovascular Disease, and Microvascular Disease in Adults With Obesity

OBJECTIVE

To assess the association between timing of aerobic moderate to vigorous physical activity (MVPA) and risk of cardiovascular disease (CVD), microvascular disease (MVD), and all-cause mortality in adults with obesity and a subset with obesity and type 2 diabetes (T2D).

RESEARCH DESIGN AND METHODS

Participants included adults with obesity (BMI ≥30 kg/m2) and a subset of those with T2D from the UK Biobank accelerometry substudy. Aerobic MVPA was defined as bouts of MVPA lasting ≥3 continuous minutes. Participants were categorized into morning, afternoon, or evening MVPA based on when they undertook the majority of their aerobic MVPA. The reference group included participants with an average of less than one aerobic MVPA bout per day. Analyses were adjusted for established and potential confounders.

RESULTS

The core sample included 29,836 adults with obesity, with a mean age of 62.2 (SD 7.7) years. Over a mean follow-up period of 7.9 (SD 0.8) years, 1,425 deaths, 3,980 CVD events, and 2,162 MVD events occurred. Compared with activity in the reference group, evening MVPA was associated with the lowest risk of mortality (hazard ratio [HR] 0.39; 95% CI 0.27, 0.55), whereas afternoon (HR 0.60; 95% CI 0.51, 0.71) and morning MVPA (HR 0.67; 95% CI 0.56, 0.79) demonstrated significant but weaker associations. Similar patterns were observed for CVD and MVD incidence, with evening MVPA associated with the lowest risk of CVD (HR 0.64; 95% CI 0.54, 0.75) and MVD (HR 0.76; 95% CI 0.63, 0.92). Findings were similar in the T2D subset (n = 2,995).

CONCLUSIONS

Aerobic MVPA bouts undertaken in the evening were associated with the lowest risk of mortality, CVD, and MVD. Timing of physical activity may play a role in the future of obesity and T2D management.

Exercise Snacks and Other Forms of Intermittent Physical Activity for Improving Health in Adults and Older Adults: A Scoping Review of Epidemiological, Experimental and Qualitative Studies

Exercise snacks, including other variants of brief intermittent bouts, are an emerging approach for increasing physical activity, although their operationalisation is unstandardised and their health benefits remain unclear. This scoping review aimed to explore characterisations of exercise snacks and summarise their effects on health in adults and older adults. Clinical trial registers (clinicaltrials.gov and ANZCTR) and electronic databases (PubMed, CINAHL, CENTRAL, PsycINFO) were searched from inception to 1 June 2023, for ongoing and published studies of exercise snacks. Backwards and forwards citation tracking was also conducted to identify additional eligible studies. Studies were included if they investigated exercise snacks-brief intermittent bouts of physical activity spread across the day-in adults or older adults. We included epidemiological, experimental, quasi-experimental and qualitative studies that examined the effect of exercise snacks on any health outcomes or described barriers to and enablers of these approaches. Thirty-two studies were included (7 trial registers, 1 published protocol, 3 epidemiological studies and 20 trials reported across 21 studies). Three main terms were used to describe exercise snacks: exercise snack(ing), snacktivity and vigorous intermittent lifestyle physical activity (VILPA). Participants were predominantly physically inactive but otherwise healthy adults or older adults. Exercise snacks were feasible and appeared safe. Epidemiological studies showed steep, near-linear associations of VILPA with reduced all-cause, cardiovascular and cancer mortality as well as reduced incidence of major adverse cardiovascular events and cancer. The limited trial evidence showed exercise snacks had modest effects on improving cardiorespiratory fitness, whereas effects on physical function, mood, quality of life and other health outcomes were equivocal. In conclusion, exercise snacks appear feasible and safe for adults and older adults and may have promising health benefits, but this is mostly based on findings from a limited number of small quasi-experimental studies, small randomised trials or qualitative studies. More studies are needed in individuals with chronic disease. This emerging physical activity approach may have appeal for individuals who find structured exercise unfeasible.Registration https://osf.io/qhu24/.

Do the associations of daily steps with mortality and incident cardiovascular disease differ by sedentary time levels? A device-based cohort study

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.

Long-term physical activity time-in-target range in young adults with cardiovascular events in later life

AIMS

Achieving at least 150 min per week of moderate-to-vigorous physical activity (PA) is a 'Class I, A level' recommendation for the primary prevention of cardiovascular disease. However, long-term PA is a complex behaviour and varied by lifetime, which was insufficiently reflected by the current studies. This study used time-in-target range (TTR) to measure the long-term PA level during young adulthood and investigated its relationship with cardiovascular events in later life.

METHODS AND RESULTS

Participants in the Coronary Artery Risk Development in Young Adults study were recruited (n = 2902) and allocated into four groups by PA TTR: <25% (n = 1028), 25 to <50% (n = 444), 50 to <75% (n = 424), 75 to 100% (n = 1006). TTR was estimated with linear interpolation across the first 15 years. The primary outcome was a composite of cardiovascular events. The mean (SD) age after the exposure period was 40.3 (3.6) years. After a median follow-up for an additional 18.9 years, the participants with a TTR of at least 75% had a 40% lower risk of the primary outcome (HR: 0.60; 95%CI: 0.38 to 0.95) compared with the lowest TTR group. Each 1-SD increase in TTR was also significantly associated with a 21% decreased risk of the primary outcome (HR: 0.79; 95%CI: 0.65-0.97).

CONCLUSION

Increasing PA is essential in young adulthood. In young adults, maintaining long-term guidelines-recommended PA levels may help to lower the risk of cardiovascular events in later life. Maintaining the guidelines-recommended PA level for at least 75% of time across young adulthood may be preferable.