1 Physical Activity, Health, and Chronic Disease chapter 1 chapter Author name here for Edited books

Objectives Understand the importance of regular physical activity Understand dose–response relationships Understand the concept of training volume Identify risk factors for cardiovascular disease and sources of musculoskeletal disorders and disease Appreciate the role of different exercise types in optimizing health

Importance of Physical Activity Regular physical activity (PA) confers many health benefits and helps prevent chronic diseases National health objective is to increase the number of U.S. adults engaging in regular PA to 30% Target PA goal for the national health objective Minimum of 30 minutes Moderate intensity Most if not all days of week (continued)

Figure 1.1

Global Challenge Physical inactivity is a global problem. Your goal: educate and motivate clients to adopt a physically active lifestyle. Physical inactivity may be the most important health problem of the 21st century.

CDC and ACSM Recommendations 1995 recommendation: Every U.S. adult should accumulate which was updated in 2007: 30 min, moderate-intensity PA, on most, preferably all, days of the week. Recommended PA is in addition to ADLs Intensity is expressed in METs Definitions for moderate- and vigorous-intensity PA Resistance training recommendation Balance and flexibility suggestion for older adults (continued)

AHA and ACSM Definitions Moderate intensity: 3 to 6 METs or 5 to 6 on 10-point rating of perceived exertion (RPE) scale Results in noticeable increase in heart rate (HR) and lasts >10 min Vigorous intensity: >6 METs or 7 to 8 on 10-point RPE scale Results in rapid breathing and substantial increase in HR (continued)

Current AHA and ACSM Recommendations Adults (18 years) At least 30 minutes moderate-intensity aerobic PA 5 days a week or 20 minutes vigorous-intensity aerobic PA 3 days a week Minimum 2 days a week moderate- to high-intensity resistance training 8 to 12 repetitions maximum (RM) for 18 to 64 years 10- to 15RM for older (65 years) adults Balance and flexibility for those 65 years (continued)

2008 PA Guidelines for Americans Children need 60 min PA daily: Primarily moderate- or vigorous-intensity PA Minimum 3 days a week vigorous-intensity PA Minimum 3 days a week muscle- and bone-strengthening PA

Health Benefits of PA Lowers risk of premature death and chronic conditions Reduces depression, anxiety, abdominal obesity Helps control weight Improves sleep quality Improves cognitive function Maintains and improves bone density Prevents falls Increases functional health

How Much PA is Enough? Benefits based on training volume Dose–response relationship: what kcal/wk expenditure required for specific improvement Additional potential benefits for exceeding minimum recommended PA levels

Dose-Response Relationship 1,000 kcal/wk Sufficient to reduce disease risk A great initial goal for some Enough to move from sedentary to low PA level Insufficient to maintain healthy body weight Insufficient to experience full health benefits Greater dose (~2,000 kcal/wk) required to maintain healthy body weight, prevent weight gain, provide additional health benefits, and move a person from a sedentary to active PA level.

Figure 1.2 Dose-response relationship for health benefits and volume of physical activity.

Figure 1.3

Cardiovascular Disease (CVD) Major cause of death in U.S. and Europe Causes 17.5 million deaths worldwide each year Accounted for 36.3% of deaths in US (1 out of every 3) Includes hypertension, heart disease, congestive heart failure, and stroke No longer a disease of men or the elderly Associated with inactivity and sedentarism (lack of cardiorespiratory fitness)

Coronary Heart Disease (CHD) CHD is Myocardial ischemia - imbalance between coronary oxygen supply and demand, Attributable to physical inactivity and sedentarism, and Attributed to atherosclerosis May result in angina pectoris (chest discomfort and pain) and myocardial infarction (heart attack) (continued)

CHD Risk Factors Age Family history Hypercholesterolemia Hypertension Current cigarette smoking Prediabetes Obesity Physical inactivity

Hypertension High blood pressure Prehypertension Major contributor to stroke and heart attack, SBP  140 mmHg or DBP  90 mmHg or on medication(s) for blood pressure. Prehypertension SBP between 120 and 139 mmHg or DBP between 80 and 89 mmHg Inverse relationship exists between hypertension and PA level. (continued)

Hypercholesterolemia and Dyslipidemia Hypercholesterolemia = high total cholesterol (TC) Also known as hyperlipidemia (high blood lipid levels) Dyslipidemia = abnormal blood lipid level High TC and/or high low-density lipoproteins (LDL-C) and/or low high-density lipoproteins (HDL-C) (continued)

Cigarette Smoking Largest preventable cause of disease and premature death Smokers’ risk of heart attack is 2 times nonsmokers’, Smoking is linked to CHD, stroke, chronic lung disease, and several cancers. Risk for CHD declines rapidly with quitting Risk declines 50% in the first year. Relative risk of stroke and CHD death is similar to that of nonsmokers in 15 years. (continued)

Type 1 (IDDM) Diabetes Usually occurs before age 30 However, can develop at any age Not as common as type 2 Exercise prescriptions should follow specific guidelines

Type 2 (NIDDM) Diabetes Most common form of DM Risk factors for NIDDM related to age, family history, diet, above-normal body weight and body fat Healthy lifestyle choices decrease risk

Obesity and Overweight Categories defined by body mass index (BMI) BMI = [kg/(m2)] Overweight = BMI between 25 and 29.9 kg/m2 Obese = BMI  30 kg/m2 Obesity shortens life expectancy and increases risk for the following: CHD DM Hypercholesterolemia Hypertension Osteoarthritis Some cancers (continued)

Causes of Obesity and Overweight Some evidence for genetic source Majority of evidence points to environment Restricting caloric intake and increasing caloric expenditure are good ways to control weight, decrease body fatness, and normalize blood lipids and blood pressure. (continued)

Metabolic Syndrome Cluster of specific CVD risk factors Must have at least 3 of those risk factors Increases risk of CHD and DM Prevalence highest for older (>60 yr) and obese people

Cancer A leading cause of death worldwide Key risk factors include physical inactivity To reduce cancer risk: 45 to 60 minutes a day of moderate-intensity PA, at least 5 days a week for adults 60 minutes a day, moderate- to vigorous-intensity PA at least 5 days a week for children and adolescents Maintain healthy weight

Musculoskeletal Issues Sedentarism and physical inactivity contribute to musculoskeletal diseases and disorders Osteoporosis Osteopenia Low back pain Origins may be functional, not structural. Poor lifestyle choices increase the likelihood of experiencing low back pain.