Lack of Cited Evidence Underpinning Recommendations for Objective Assessment of Cardiovascular Function to Inform Exercise Prescription: A Systematic Review.

BACKGROUND: The effectiveness of exercise in managing cardiovascular (CV) health and function is well established. Less clear is the process for optimising the safety and efficacy of an intervention, particularly how objective assessments might inform this process. OBJECTIVE: The aim of this review was to investigate the cited evidence underpinning recommendations for assessing CV function to inform the safe and effective prescription of exercise in populations with established CV disease, as published in documents to guide practice authored by prominent organisations in cardiology and sports medicine. METHODS: A systematic review of position statements and guiding documents on exercise prescription for CV health was conducted. Included documents were published between 1997 and 2016. RESULTS: Following removal of duplicates, 3158 documents were considered, with full-text screening required for 334. Twenty-seven documents were included which provided 106 individual recommendations for specific objective assessments. Of the total number of recommendations, 60% had no accompanying citation and 28% of recommendations provided citations that did not directly support the statement made. Additionally, 52% of included documents did not state the methods of document development. That is, it was not clear if there was a literature review and/or expert consensus that was used to form recommendations included within. CONCLUSION: Almost no cited evidence underpinning the extracted recommendations from the included guiding documents, nor any acknowledgement of this deficiency was established. There were limited explanations found for the methods involved in developing such guiding documents.

Physiological and Perceived Exertion Responses during Exercise: Effect of ß-blockade.

PURPOSE: This study investigated the effect of ß-blockade on physiological and perceived exertion (RPE) responses during incremental treadmill exercise. METHODS: Sixteen healthy participants (n = 8 men; age, 25.3 ± 4.6 yr) performed a maximal treadmill exercise test after ingestion of 100 mg metoprolol or placebo, with a double-blind, randomized, and counterbalanced design. Heart rate (HR), ventilatory, and gas exchange variables were measured continuously, and participants reported RPE at the end of each minute. Physiological and RPE responses during each condition were compared at the ventilatory threshold (VT), respiratory compensation point, and at maximal exercise using repeated-measures ANOVA. Linear regression modeled relationships between perceived exertion and physiological variables. RESULTS: The HR and V˙O2 at the VT, respiratory compensation point, and maximal exercise were all significantly lower after ß-blockade (P < 0.05). However, when standardized to within condition peak values, differences were no longer significant. The RPE associated with VT was higher after ß-blockade (12.9 ± 1.0 vs 12.3 ± 1.2, P < 0.05) but lower at maximal exercise (19.1 ± 0.6 vs 19.4 ± 0.5, P < 0.05). Increases in RPE relative to HR were greater after ß-blockade and remained significant when expressed relative to peak HR. There was no difference in the growth of the relationship between RPE and V˙O2 across conditions, although the origin of the relationship was higher with ß-blockade. CONCLUSIONS: Although ß-blockade resulted in a significant reduction in exercising HR and V˙O2, the RPE for a given relative intensity remained unchanged. The relationship between RPE and V˙O2 was not affected by ß-blockade. The results provide evidence that RPE is a useful and reliable measure for exercise testing and prescription in patients prescribed ß-blockade therapy.

What is the effect of aerobic exercise intensity on cardiorespiratory fitness in those undergoing cardiac rehabilitation? A systematic review with meta-analysis.

OBJECTIVE: Assess the role of exercise intensity on changes in cardiorespiratory fitness (CRF) in patients with cardiac conditions attending exercise-based cardiac rehabilitation. DESIGN: Systematic review with meta-analysis. DATA SOURCES: MEDLINE, Embase, CINAHL, SPORTDiscus, PsycINFO and Web of Science. ELIGIBILITY CRITERIA FOR SELECTION: Studies assessing change in CRF (reported as peak oxygen uptake; V̇O2peak) in patients post myocardial infarction and revascularisation, following exercise-based cardiac rehabilitation. Studies establishing V̇O2peak via symptom-limited exercise test with ventilatory gas analysis and reported intensity of exercise during rehabilitation were included. Studies with mean ejection fraction <40% were excluded. RESULTS: 128 studies including 13 220 patients were included. Interventions were classified as moderate, moderate-to-vigorous or vigorous intensity based on published recommendations. Moderate and moderate-to-vigorous-intensity interventions were associated with a moderate increase in relative V̇O2peak (standardised mean difference±95% CI=0.94±0.30 and 0.93±0.17, respectively), and vigorous-intensity exercise with a large increase (1.10±0.25). Moderate and vigorous-intensity interventions were associated with moderate improvements in absoluteV̇O2peak (0.63±0.34 and 0.93±0.20, respectively), whereas moderate-to-vigorous-intensity interventions elicited a large effect (1.27±0.75). Large heterogeneity among studies was observed for all analyses. Subgroup analyses yielded statistically significant, but inconsistent, improvements in CRF. CONCLUSION: Engagement in exercise-based cardiac rehabilitation was associated with significant improvements in both absolute and relative V̇O2peak. Although exercise of vigorous intensity produced the greatest pooled effect for change in relative V̇O2peak, differences in pooled effects between intensities could not be considered clinically meaningful. REGISTRATION: Prospero CRD42016035638.

Promoting physical activity in rural Australian adults using an online intervention.

OBJECTIVES: Rural Australian adults are consistently identified as insufficiently active, likely due to challenges implementing community-based physical activity programs in rural settings. On-line strategies to promote physical activity may be particularly effective in rural settings where isolation and scarcity of qualified support are potential barriers. The Rural Environments and Community Health (REACH) study evaluated the effectiveness of an online-delivered walking intervention among South Australian rural adults. DESIGN: Randomised controlled study design. METHODS: A twelve-week intervention, with six- and twelve-month follow-up, was conducted. Participants (n=171; 50.6±12.5years), recruited through flyers, local newspapers and radio, were randomised to comparison or intervention groups and received a pedometer. The intervention group received access to the REACH website and personalised step goals based on ratings of perceived exertion and daily affect. The comparison group received a paper diary and generic step goals. Outcome measures were accelerometry-assessed sedentary, light (LPA) and moderate-to-vigorous (MVPA) physical activity. Linear mixed models assessed changes over the intervention and follow-ups. RESULTS: Sedentary time decreased, and LPA and MVPA increased in both groups across the intervention (p<0.05). The intervention group demonstrated a larger increase in LPA at six-month follow-up relative to comparison (p<0.05). Both groups decreased sedentary time, overall and in bouts ≥30min, between baseline and twelve-month follow-up (p<0.05). From baseline to twelve-month follow-up, MVPA (total min and bouts ≥10min) declined more in the comparison group than the intervention group (p<0.05). CONCLUSION: While increased physical activity and decreased sedentary time were observed in both groups during the intervention period, maintenance was only observed for LPA at six-month follow-up in the intervention group. By twelve-month follow-up, post-intervention improvements had largely disappeared, suggesting that additional research is needed to identify ways to improve long-term adherence.

Associations of physical activity and sedentary behaviour with metabolic syndrome in rural Australian adults.

OBJECTIVES: Associations between objectively measured sedentary behaviour, physical activity (PA) and metabolic syndrome (MetS)-classified using three different definitions were investigated in an inactive sample of rural Australian adults. DESIGN: Quantitative, cross-sectional. METHODS: 171 adults (50.7±12.4years) from two rural South Australian regions underwent seven-day accelerometer activity monitoring and MetS classification using the National Cholesterol Education Program, the International Diabetes Federation and the Harmonized definitions. Associations between sedentary and activity variables and MetS (adjusted for age, sex, diet and smoking status) were modelled using logistic regression. In secondary modelling, associations of sedentary and activity outcomes for each MetS definition were assessed, adjusting for other activity and sedentary variables. Prediction differences across the definitions of MetS were directly compared using Akaike's Information Criterion. RESULTS: Sedentary behaviour increased MetS risk, whereas light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA) reduced MetS risk, irrespective of definition. In secondary models, LPA predicted MetS independently of MVPA and total sedentary time. Time spent in sedentary bouts (>30min) predicted MetS independently of MVPA and the number of sedentary bouts predicted MetS independently of LPA and MVPA. Prediction differences for MetS definitions failed to reach the critical threshold for difference (>10). CONCLUSIONS: This study highlights the importance of sedentary behaviour and LPA on the prevalence of MetS in an inactive sample of rural Australian adults. Studies assessing the efficacy of increasing LPA on MetS in this population are needed. Minimal predictive differences across the three MetS definitions suggest evidence from previous studies can be considered cumulative.

Cardiac Rehabilitation for Patients With Coronary Artery Disease: A Practical Guide to Enhance Patient Outcomes Through Continuity of Care.

Coronary artery disease (CAD) is a leading cause of disease burden worldwide. Referral to cardiac rehabilitation (CR) is a class I recommendation for all patients with CAD based on findings that participation can reduce cardiovascular and all-cause mortality, as well as improve functional capacity and quality of life. However, programme uptake remains low, systematic progression through the traditional CR phases is often lacking, and communication between health care providers is frequently suboptimal, resulting in fragmented care. Only 30% to 50% of eligible patients are typically referred to outpatient CR and fewer still complete the programme. In contemporary models of CR, patients are no longer treated by a single practitioner, but rather by an array of health professionals, across multiples specialities and health care settings. The risk of fragmented care in CR may be great, and a concerted approach is required to achieve continuity and optimise patient outcomes. 'Continuity of care' has been described as the delivery of services in a coherent, logical, and timely fashion and which entails 3 specific domains: informational, management, and relational continuity. This is examined in the context of CR.

Rural Environments and Community Health (REACH): a randomised controlled trial protocol for an online walking intervention in rural adults.

BACKGROUND: Rural Australian adults are continually shown to be insufficiently active with higher prevalence of lifestyle-related diseases associated with physical inactivity compared to urban adults. This may, partly, be attributable to the challenges associated with implementing community-based physical activity programs in rural communities. There is a need for broadly accessible physical activity programs specifically tailored to the unique attributes of rural communities. The aim of the Rural Environments And Community Health (REACH) study is to evaluate the effectiveness of an online-delivered physical activity intervention for increasing regular walking among adults living in rural areas of South Australia. METHODS/DESIGN: This is a randomised controlled trial. The intervention is 12-weeks with a 12-month follow-up. Participants will be insufficiently active, aged 18 to 70 years and randomly assigned to either Control or Intervention group. Participants receive a pedometer, but only the Intervention group will receive access to the purpose built REACH website where they will report steps taken, affect and ratings of perceived exertion during daily walking. These variables will be used to establish individualised step goals for increasing walking. Control participants will receive a paper diary to record their variables and generic incremental step goals.The primary outcome measures are time spent in sedentary, light and moderate-to-vigorous intensity physical activity, measured by accelerometry. Secondary outcomes include 1) health measures (anthropometric and physiological), 2) psychological well-being, 3) diet quality, and 4) correlates of physical activity (exercise self-efficacy and physical activity environments). Measures will be collected at baseline, post-intervention, 6-month and 12-month follow-up. DISCUSSION: This protocol describes the implementation of a trial testing the effectiveness of an online resource designed to assist rural Australians to become more physically active. The outcomes of this study will guide the efforts of health promotion professionals by providing evidence for a relatively inexpensive, widely accessible and effective method for increasing physical activity that can be utilized by anyone with access to the internet. Findings may indicate future directions for the implementation of physical activity and other health related interventions in rural communities. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry: ACTR12614000927628 (registered 28 August 2014).