Health benefits of physical activity: the evidence Review

P hysical inactivity is a modifiable risk factor for cardiovascular disease and a widening variety of other chronic diseases, including diabetes mellitus, cancer (colon and breast), obesity, hypertension, bone and joint diseases (osteoporosis and osteoarthritis), and depression. 1-14 The prevalence of physical inactivity (among 51% of adult Canadians) is higher than that of all other modifiable risk factors. Several authors have attempted to summarize the evidence in systematic reviews and meta-analyses. These evaluations are often overlapping (reviewing the same evidence). Some of the most commonly cited cohorts have been described in different studies over time as more data accumulate (see Appendix 2, available online at www.cmaj.ca/cgi/content/full/174/6 /801/DC1). In this review, we searched the literature using the key words "physical activity," "health," "health status," "fitness," "exercise," "chronic disease," "mortality" and diseasespecific terms (e.g., "cardiovascular disease," "cancer," "diabetes" and "osteoporosis"). Using our best judgment, we selected individual studies that were frequently included in systematic reviews, consensus statements and meta-analyses and considered them as examples of the best evidence available. We also have included important new findings regarding the relation between physical activity and fitness and allcause and cardiovascular-related mortality. All-cause and cardiovascular-related death Primary prevention Since the seminal work of Morris and colleagues in the 1950s 16,17 and the early work of Paffenbarger and colleagues in the 1970s, 18,19 there have been numerous long-term prospective follow-up studies (mainly involving men but more recently women also) that have assessed the relative risk of death from any cause and from specific diseases (e.g., carciovascular disease) associated with physical inactivity. 6,20-26 Both men and women who reported increased levels of physical activity and fitness were found to have reductions in relative risk (by about 20%-35% 27,28 ) of death (see Appendix 2, available at www.cmaj.ca/cgi/content/full/174/6/801/DC1). For example, in a study involving healthy middle-aged men and women followed up for 8 years, the lowest quintiles of physical fitness, as measured on an exercise treadmill, were associated with an increased risk of death from any cause compared with the top quintile for fitness (relative risk among men 3.4, 95% confidence interval [CI] 2.0 to 5.8, and among women 4.7, 95% CI 2.2 to 9.8). 7 Recent investigations have revealed even greater reductions in the risk of death from any cause and from cardiovascular disease. For instance, being fit or active was associated with a greater than 50% reduction in risk. 29 Furthermore, an increase in energy expenditure from physical activity of 1000 kcal (4200 kJ) per week or an increase in physical fitness of 1 MET (metabolic equivalent) was associated with a mortality benefit of about 20%. Physically inactive middle-aged women (engaging in less than 1 hour of exercise per week) experienced a 52% increase in all-cause mortality, a doubling of cardiovascularrelated mortality and a 29% increase in cancer-related mortality compared with physically active women. 30 These relative risks are similar to those for hypertension, hypercholesterolemia and obesity, and they approach those associated with moderate cigarette smoking. Moreover, it appears that people who are fit Review The primary purpose of this narrative review was to evaluate the current literature and to provide further insight into the role physical inactivity plays in the development of chronic disease and premature death. We confirm that there is irrefutable evidence of the effectiveness of regular physical activity in the primary and secondary prevention of several chronic diseases (e.g., cardiovascular disease, diabetes, cancer, hypertension, obesity, depression and osteoporosis) and premature death. We also reveal that the current Health Canada physical activity guidelines are sufficient to elicit health benefits, especially in previously sedentary people. There appears to be a linear relation between physical activity and health status, such that a further increase in physical activity and fitness will lead to additional improvements in health status. CMAJ 2006;174(6):801-9 Abstrac

The Health Benefits and Challenges of Exercise Training in Persons Living with Schizophrenia : A Pilot Study

Background: In addition to the hallmark cognitive and functional impairments mounting evidence indicates that schizophrenia is also associated with an increased risk for the development of secondary complications, in particular cardio-metabolic disease. This is thought to be the result of various factors including physical inactivity and the metabolic side effects of psychotropic medications. Therefore, non-pharmacological approaches to improving brain health, physical health, and overall well-being have been promoted increasingly. Methods: We report on the health-related physical fitness (body composition, blood pressure, heart rate, and aerobic fitness) and lipid profile of persons living with schizophrenia and effective means to address the challenges of exercise training in this population. Results: There was a markedly increased risk for cardio-metabolic disease in 13 persons living with schizophrenia (Age = 31 ± 7 years) including low aerobic fitness (76% ± 34% of predicted), reduced HDL (60% of cohort), elevated resting heart rate (80% of cohort), hypertension (40% of cohort), overweight and obesity (69% of cohort), and abdominal obesity (54% of cohort). Individualized exercise prescription (3 times/week) was well tolerated, with no incidence of adverse exercise-related events. The exercise adherence rate was 81% ± 21% (Range 48%–100%), and 69% of the participants were able to complete the entire exercise training program. Exercise training resulted in clinically important changes in physical activity, aerobic fitness, exercise tolerance, blood pressure, and body composition. Conclusion: Persons living with schizophrenia appear to be at an increased risk for cardio-metabolic disease. An individualized exercise program has shown early promise for the treatment of schizophrenia and the various cognitive, functional, and physiological impairments that ultimately affect health and well-being.Education, Faculty ofMedicine, Faculty ofOther UBCKinesiology, School ofRadiology, Department ofReviewedFacult

Cardiovascular dynamics of Canadian Indigenous peoples

Limited understanding of Indigenous adults’ cardiovascular structure and function exists despite high rates of cardiovascular disease. This investigation characterised cardiovascular structure and function among young Indigenous adults and compared to age- and sex-matched European descendants. Echocardiographic assessments included apical two- and four-chamber images, parasternal short-axis images and Doppler. Analyses included cardiac volumes, dimensions, velocities and strains. Cardiovascular structure and function were similar between Indigenous (n=10, 25 ± 3 years, 4 women) and European-descendant (n=10, 24 ± 4 years, 4 women,) adults, though European descendants demonstrated greater systemic vascular resistance (18.19 ± 3.94 mmHg∙min−1∙L−1 vs. 15.36 ± 2.97 mmHg∙min−1∙L−1, p=0.03). Among Indigenous adults, women demonstrated greater arterial elastance (0.80 ± 0.15 mmHg·mL−1·m−2 vs. 0.55 ± 0.17 mmHg·mL−1·m−2, p=0.02) and possibly greater systemic vascular resistance (17.51 ± 2.20 mmHg∙min−1∙L−1 vs. 13.93 ± 2.61 mmHg∙min−1∙L−1, p=0.07). Indigenous men had greater cardiac size, dimensions and output, though body size differences accounted for cardiac size differences. Similar cardiac rotation and strains were observed across sexes. Arterial elastance and cardiac size were different between Indigenous men and women while cardiovascular structure and function may be similar between Indigenous and European descendants

Effectiveness of Approaches to Increase Physical Activity Behavior to Prevent Chronic Disease in Adults: A Brief Commentary

Effective behavior change approaches are necessary to help individuals avoid or mitigate risk factors, engage in behavioral patterns that lead to better health, and consequently, prevent several chronic diseases. Physical inactivity is considered one of the most harmful risk factors for chronic medical conditions, and although different strategies are used to tackle this behavior, not all of them lead to the expected or desired results. This brief commentary examines recent approaches aimed at physical activity behavior change. We find that a combination of strategies focusing on streamlining the access to physical activity seems to be more effective than individual approaches, in order to increase physical activity engagement to prevent chronic diseases in adults.Other UBCNon UBCReviewedFacult

Readiness for Firefighting: A Heart Transplant Patient’s Quest to Return to Work

Heart transplantation patients generally demonstrate exercise capacities that are below the minimal standards for firefighting. Therefore, it is unlikely that heart transplantation patients will receive medical and/or employer clearance for active duty. We report a case of a firefighter who sought to return to full-time active duty following heart transplantation. We examined his physiological readiness to return to work during occupation-specific testing. Remarkably, the patient was able to meet the minimal requirements for full active firefighting. This finding provides direct evidence to support the potential of transplant patients returning to active duty in physiologically demanding occupations.Education, Faculty ofOther UBCNon UBCKinesiology, School ofReviewedFacult

Association between Inter-Limb Asymmetries in Lower-Limb Functional Performance and Sport Injury: A Systematic Review of Prospective Cohort Studies

Background: Inter-limb asymmetry in lower-limb functional performance has been associated with increased risk of sport injury; however, findings are not always consistent. Purpose: To conduct a systematic review on whether inter-limb asymmetry in lower-limb functional performance can predict sport injury. Methods: Four electronic databases (MEDLINE, EMBASE, Web of Science, and SportDiscus) were systematically searched for prospective cohort studies reporting the association between inter-limb asymmetry in lower-limb functional performance and sport injury. Results: A total of 28 prospective cohort studies were included in the analyses. Collectively, the findings were highly inconsistent, and a clear statement on the association between each asymmetry and sport injury was difficult. Conclusions: Highly inconsistent findings make it difficult to create clear recommendations on the relationship between the inter-limb asymmetry in lower-limb functional performance (power, muscle flexibility, and dynamic balance) and sport injury. The influence of potential factors (selection of tests/parameters, participant characteristics, definition of injury, and ways of calculating asymmetry) should be considered when using previous findings.Education, Faculty ofMedicine, Faculty ofNon UBCExperimental Medicine, Division ofKinesiology, School ofMedicine, Department ofReviewedFacult

Cardiovascular Health Benefits of Exercise Training in Persons Living with Type 1 Diabetes: A Systematic Review and Meta-Analysis

Exercise is advocated in the management of type 1 diabetes (T1D), but the effects of different forms of exercise training on cardiovascular risk factors in T1D still remain unclear. The aim of this study was to conduct a systematic review and meta-analysis on exercise training for cardiovascular risk factors in T1D. Six electronic databases were systematically searched for randomized or non-randomized controlled studies reporting associations between exercise training and cardiovascular risk factors in T1D. Weighted mean differences (WMD) of each cardiovascular risk factor between exercise groups and control groups were calculated using a random effects model. A total of 24 studies reported the effects of exercise training on cardiovascular risk factors. Exercise training increased maximal aerobic power (3.01 mL·kg⁻¹·min⁻¹, 95% confidence interval, CI, 0.94 to 6.38) and reduced glycated hemoglobin (HbA1c; −0.45%, 95% CI −0.73 to −0.17), daily insulin dosage (−0.88 U·kg⁻¹, 95% CI −1.27 to −0.48), and total cholesterol (−0.38 mmol·L⁻¹, 95% CI −0.71 to −0.04). Exercise training did not lead to consistent changes in body mass index (BMI), blood pressure, triglycerides, high-density lipoprotein cholesterol (HDL-C), or low-density lipoprotein cholesterol (LDL-C). In persons living with T1D, exercise training is associated with a beneficial cardiovascular profile, including improvements in lipid profile, glycemic control (decreased daily insulin dosage and HbA1c), and aerobic fitness.Education, Faculty ofOther UBCKinesiology, School ofReviewedFacult

Development of the Brazilian Version of a Pan-Canadian Behavior Change Program and Its Health and Fitness Outcomes

Chronic diseases are a major health problem worldwide, especially in lower-income jurisdictions. Considering this scenario, the World Health Organization has recently established, as a research priority, preventive interventions for populations from lower-income countries, such as the middle-income country of Brazil. The purpose of this article is to describe the components of a pan-Canadian lifestyle program adapted to Brazilians and to report its health and fitness outcomes. A 12-week program called ACCELERATION was translated and culturally adapted to Brazilians. A quasi-randomized controlled trial was designed, consisting of weekly emails and educational videos addressing risk factors for chronic disease. Health and fitness measures included body composition, cardiovascular variables, aerobic fitness, and muscular strength. The Brazilian experimental group showed maintenance in heart rate, blood pressure, and VO2max values while presenting an improvement of 3.3% in body fat percentage (p = 0.040, d = −0.325) and 5.1% in muscular strength (p = 0.039, d = 0.328). Overall, these results were similar to the Canadian intervention. Based on these findings, the Brazilian version of the program has the potential to contribute to the fight against chronic diseases in Brazil