By lorceh | In novedades y ciencia del deporte | on November 8, 2012

The benefits of a regular exercise program extend into many areas of life. Exercise is one intervention that is inexpensive and simple and can provide many life-enhancing advantages. Improvements in body function as a result of exercise are well documented. In addition to physiological benefits, psychological benefits can also be realized. Exercise is the best prescription! No other “product” can provide so many positive changes with so few side effects. For a comprehensive list of the health benefits related to physical activity for all age groups from children to older adults, see table 1.1.18 The scientists working with the U.S. Department of Health and Human Services rated available evidence as strong, moderate, or weak based on the type, number,

and quality of the research studies. Only the health benefits with at least moderate evidence are included in this table. As a reader of this book, you can claim these benefits for yourself. Be encouraged! Regardless of your current level of physical activity, the information provided in the upcoming chapters will help you create a realistic, workable exercise plan that has the potential to change your life for the better. It is time to get up and get moving!

Physiological Benefits Physiology deals with how the body functions. To maintain optimal function, the body must be exposed to positive stressors such as exercise. Consider a complete exercise program as including three components: aerobic fitness, muscular fitness, and flexibility. Each component contributes to ensuring that your body is operating at its optimal level. This influences your ability not only in exercise performance but also in activities of daily living. Aerobic Fitness When you exercise so that your heart beats faster and you breathe at a quicker rate, you are providing a positive stress on your cardiorespiratory system as well as your entire body. An inactive lifestyle does not provide this positive stress and therefore leads to inactivity-related diseases such as heart disease. A sedentary lifestyle and obesity have been described as “parallel, interrelated epidemics in the United States” related to their contribution to the risk of heart disease.9 It is vital to find ways to fit physical activity into your daily life. Regular activity is associated with lowering risk factors related to heart disease such as high blood pressure and unhealthy cholesterol levels. If you are already somewhat active, you can further reduce your risk by engaging in additional physical activity. Heart health is discussed in more depth in chapter 12; weight management, in chapter 13; high blood pressure, in chapter 15; and high cholesterol, in chapter 16. Physical activity also reduces the risk of type 2 diabetes.4 Progression from prediabetes (elevated blood glucose levels that increase the risk of developing diabetes in the future) to diabetes can be delayed or even prevented by losing weight and increasing physical activity.4 Lifestyle modifications can have a definite impact. In addition to helping people avoid type 2 diabetes, physical activity can also help control blood glucose levels in people diagnosed with either type 1 or type 2 diabetes.18 Details on the benefits of exercise for those with diabetes are provided in chapter 14. A dose-response relationship exists between physical activity and health. This simply means that doing some activity is better than being completely inactive and that more activity, up to a point, is better than less activity. In other words, more exercise will continue to lower the likelihood of unhealthy situations such as heart disease, overweight and obesity, and type 2 diabetes.1 The more activity you include in your life, the lower your risk will be. Whether you are a beginner or an established exerciser, additional exercise provides added health rewards and greater fitness. Chapter 6 explains more fully the recommendations on aerobic activity as well as how you can progress over time. Muscular Fitness When considering muscular fitness, the first picture in your mind might be a competitive athlete with large muscles. Although increases in muscle size are possible with resistance training, for most people a more relevant reason to include resistance training is to improve muscle function in order to handle activities of daily living with less stress. For example, sufficient muscular fitness will allow you to climb stairs more easily or complete yardwork with less relative effort. Of course, improved muscular fitness will also make recreational sports and athletic endeavors more enjoyable and give you a competitive edge. Resistance training is important for everyone throughout the lifespan. Children benefit from activities that strengthen muscles such as climbing and jumping as well as calisthenics and more organized resistance training.10 Adults have a real need to maintain resistance training because, typically, over the course of adulthood, the amount of muscle decreases while the amount of body fat increases!2 In addition, strength training improves quality of life and limits the muscle losses typically seen with aging. Another aspect of your health that benefits from resistance training is bone strength.2 As muscles contract to lift, push, or pull a heavy object, a stress is placed on the bone by way of connections between muscles and bones called tendons. When a bone is exposed to this force, it responds by increasing its mass.2 This makes bones stronger over time. Bone health is outlined in more detail in chapter 19. Not to be ignored is the way resistance training can make you look and feel. Firm, toned muscles can inspire confidence. Stronger muscles can give you a real boost as you accomplish daily activities with greater ease and improve in competitive sports as well. For all these reasons, resistance training is an important part of your weekly activity plan. Chapter 7 outlines tools to strengthen your muscles to achieve full health and fitness benefits. Flexibility Many people consider flexibility to be a characteristic that you either have or you don’t. Although it is true that some people naturally have a higher level of flexibility than others do, everyone has the potential to improve flexibility even if gymnast-type flexibility isn’t a possibility. Flexibility can vary greatly among people but also among the various joints in the body. The ability to have full movement at the joint, also referred to as a full range of motion, can be influenced by injury, disuse, and age. When a joint is not used throughout its normal or potential range of motion, full movement of the joint will be lost over time. The value of flexibility can be seen in daily activities such as bending to tie your shoes, looking over your shoulder to check for cars in traffic, or securing a back zipper, or in recreational activities such as swimming or golfing. For more detailed information and examples of specific stretching exercises, see chapter 8. Conditions such as arthritis and joint pain can result in having difficulty moving the joints through their normal range of motion. Although activity is beneficial in the treatment of arthritis, 44% of people with arthritis report no leisure time activity (compared with 36% of people without arthritis).4 Full details on flexibility as well as muscular and cardiorespiratory exercises for people with arthritis and joint pain are found in chapter 17. Psychological Benefits In addition to the well-established physical benefits of exercise are many psychological, or mental health, benefits. Exercise appears to provide relief from symptoms of depression and anxiety; in addition, it enhances self-esteem, provides more restful sleep, and promotes faster recovery from psychosocial stressors.6 Exercise also has the potential to enhance emotional well-being and

improve mood.14 Depression is marked by feeling sad and unhappy along with being self-critical and having low self-esteem.2 The U.S. Centers for Disease Control reports that during any two-week period more than 1 in 20 Americans experience depression.4 Of those reporting depression, approximately 80% also experienced some level of functional impairment, and 27% had difficulties in work and home life.4 Both aerobic exercise and resistance training have been found to be beneficial for treating mild-to-moderate depressive symptoms.13 Exercise may lessen depressive symptoms and even potentially reduce the risk of developing depression.5 Even more encouraging, exercise appears to have a similar level of effectiveness as traditional psychotherapy but without the potential side effects of medications.13 For those with diagnosed major depression, exercise has been found beneficial in conjunction with medication-based antidepressant treatments.15 Consider the advantages of exercise over traditional medical therapies: it is relatively inexpensive, it provides physical as well as psychological improvements, and the side effects found with medications are absent.3 Because every case is unique, you should seek advice from a qualified mental health professional for optimal treatment. Anxiety is an emotional state marked by excessive anticipatory worry and tension.2 Exercise is linked with reduced anxiety—both acute, state anxiety and chronic, trait anxiety.7 For those who have high levels of stress (e.g., from ongoing nerve-racking work environments), exercise may be even more beneficial in reducing anxiety than it is for those whose stress levels are typically lower.7 Stress is that feeling of being overloaded or overwhelmed to the point of feeling unable to meet the challenges of life. When faced with ongoing, chronic stress, you can reach the point at which you are unable to react to life situations. In addition, stress is associated with a number of health risks including weakening of the immune system, overeating, and adverse shifts in blood lipid levels.2 Thankfully, exercise and physical activity have potentially positive effects on stress. As an example of the beneficial effects of exercise on stress, consider heart disease. It is well known that smoking and high blood pressure increase the risk of a heart attack, but depression and stress increase the risk to the same extent.8 Hostility is also considered to be a risk factor for heart disease. Exercise training reduces depression, overall stress, and hostility by 50% to 70% and thus can help reduce the risk of heart disease.8

You may be asking, How can exercise provide so many benefits to mental health? Researchers continue to search for the answer to this seemingly simple question. Following are some potential ways exercise benefits mental well-being:7        Increases self-confidence        Provides distraction        Enhances mood        Induces physical relaxation        Enhances self-esteem        Promotes positive body image This list suggests how exercise can help you cope with difficult situations and thus enhance your mental health along with your physical health. Sociological Benefits As the familiar song “Lean on Me” by Bill Withers suggests, “We all need somebody to lean on.” Structural support (referring to social networks) in your life is provided by friends and family as well as participation in church or civic organizations.2 Functional support focuses on your perception of support; it reflects having someone to assist when needed or even just someone to talk to and whom you believe cares for you.2 Social support is important for health and well-being.2 By involving your family members, friends, and coworkers in your activity program, you can help each other make exercise a regular habit. In doing so, you claim health and well-being benefits for yourself while also helping those around you to do the same. You may also find opportunities to expand your social network with others already involved in activities of interest to you, such as by joining a running club or becoming a member of a dance studio. PHYSICAL ACTIVITY GUIDELINES

Physical activity recommendations are not new, although the message has been clarified in recent years. In 1996, the U.S. Surgeon General’s Report on Physical Activity and Health17 was considered a landmark on par with the 1964 Surgeon General’s Report on Smoking and Health. At the time of its release, the Secretary of Health and Human Services, Donna Shalala, described it as “a passport to good health for all Americans.”17 She went on to suggest that physical activity be woven into the fabric of daily life.17 The main take-home messages of the Surgeon General’s report included the following17 (for the eight major conclusions, see Major Conclusions From the Surgeon General’s Report on Physical Activity and Health):        Americans can substantially improve their health and quality of life by including moderate amounts of physical activity in their daily lives.        For those who are already achieving regular moderate physical activity, additional benefits may be gained by further increases in activity levels.        Health benefits from physical activity are achievable for most Americans. Major Conclusions From the Surgeon General’s Report on Physical Activity and Health17 People of all ages, both male and female, benefit from regular physical activity.

Significant health benefits can be obtained by including a moderate amount of physical activity on most, if not all, days of the week. Through a modest increase in daily activity, most Americans can improve their health and quality of life. Additional health benefits can be gained through greater amounts of physical activity. People who can maintain a regular regimen of activity that is of longer duration or of more vigorous intensity are likely to derive greater benefit. Physical activity reduces the risk of premature mortality in general, and of coronary heart disease, hypertension, colon cancer, and diabetes mellitus in particular. Physical activity also improves mental health and is important for the health of muscles, bones, and joints. More than 60% of American adults are not regularly active. In fact, 25% of all adults are not active at all. Nearly half of American youths 12 to 21 years of age are not vigorously active on a regular basis. Moreover, physical activity declines dramatically during adolescence. Daily enrollment in physical education classes has declined among high school students from 42% in 1991 to 25% in 1995. Research on understanding and promoting physical activity is at an early stage, but some interventions to promote physical activity through schools, worksites, and health care settings have been evaluated and found to be successful. Although the Surgeon General’s report gave high-level attention to the importance of physical activity, it did not ultimately spark the increase in physical activity desired and needed. See figure 1.1 for the trend lines for aerobic (endurance) and resistance training activities from 1997 to 2008.16 Over this 12-year time span, little has changed. In addition, notice the line showing the percentage of people who are inactive in their leisure time.16 Ideally, a steady decline would be noted in sedentary behavior, but unfortunately, there has been no significant decrease in inactivity. Armed with increased awareness of the value of physical activity provided by the Surgeon General’s report, the U.S. Department of Health and Human Services provided clear recommendations on physical activity in its 2008 Physical Activity Guidelines for Americans.18 The Physical Activity Guidelines for Americans includes information on activity for people of all ages, including those with special needs. The upcoming chapters reflect these research-based guidelines, providing more

detail on the components of a balanced exercise program and the role activity and nutrition play in promoting health and fitness throughout the lifespan as well as when faced with special health conditions. The benefits of physical activity are very real for everyone throughout the lifespan. For adults, check out your age category in figure 1.2. The most active age group is the youngest; unfortunately, activity decreases and inactivity increases with age. In a perfect scenario, 100% of people would exercise (aerobically and with resistance training) and be active in their leisure time. Currently, the percentages are far from that ideal. It is time for everyone to increase physical activity and find enjoyable ways to be more active. Children and Adolescents Regularly active youth (ages 6 to 17) appear to have a better chance of growing into healthy adults.18 Chronic diseases such as heart disease, high blood pressure, type 2 diabetes, and osteoporosis can have their roots early in life.18 Regular physical activity can lower the risk of developing these diseases. Physical activity is also a tool to help prevent obesity. Although research supports the benefits of physical activity, unfortunately, activity levels typically decrease throughout adolescence.1 To combat this activity reduction, adults should provide opportunities for physical activity, thus paving the way for lifelong physical activity habits.18 Children and adolescents are not small adults, and thus, the recommendations for physical activity are slightly different. Children should accumulate at least an hour, and up to several hours, of

age-appropriate physical activity on a daily basis. Aerobic activities such as bicycle riding, skateboarding, jumping rope, and playing soccer (or other team sports) are recommended.18 In addition, children should include muscle-strengthening activities such as push-ups, pull-ups, tug-of-war games, and swinging on playground equipment, as well as bone-strengthening activities such as hopscotch, skipping, jumping, gymnastics, and other sports (e.g., basketball, volleyball, tennis).18 Physical activity programs must be geared toward children’s and adolescents’ specific age and maturity levels.18 Including a variety of activities that youth find enjoyable is the key for continued activity into adulthood. An expanded discussion of activity and exercise recommendations for children and adolescents is found in chapter 9. Adults The benefits of a regular, balanced exercise program for adults (ages 18 to 64) are very clear. Physically active adults are typically healthier and have a lower chance of developing chronic diseases compared to their inactive peers.18 In addition, a physically active lifestyle along with good nutritional practices helps to keep body weight and body composition in a healthy range. As shown in figure 1.2, adulthood is typically a time of decreasing physical activity. To help combat this trend, chapter 10 highlights how adults can develop a plan to expand physical activity levels to include aerobic exercises as well as muscle-strengthening exercises on a regular basis. Just as adults focus on creating financial stability during these career-focused years via systematic savings and investments, so too should they consider regular exercise and proper nutrition to be investments in their health. Older Adults Older refers to adults 65 years of age or older.18 People in this age group tend to have more diversity with regard to health and fitness than younger adults. Older adults of the same chronological age may be very different in regard to health status.1 Whereas one 75-year-old may spend the day golfing and gardening, another may spend most of the day relatively inactive. Thus, the effects of aging are potentially compounded by deconditioning.1 In spite of the known health benefits of exercise, older adults are among the least active Americans. Close to half of Americans over 65 do not engage in any


leisure time physical activity4 (see figure 1.2). Summary of Physical Activity Guidelines for Americans The Physical Activity Guidelines for Americans provides a summary of hundreds of research studies conducted to examine the effects of physical activity on health. Following are some of the major findings:18        Regular physical activity reduces the risk of many unwanted health outcomes and diseases. Refer back to the list in table 1.1 to refresh your memory of the many benefits.        Some physical activity is better than none. The greatest health risk comes from being totally sedentary. Getting up and moving is important to start reducing disease risk and claiming benefits. Some health benefits have been identified with as little as 60 minutes of activity a week.        A target of 150 minutes per week of moderate-intensity activity provides significant health benefits (remember, additional benefits accrue to those who do more). An example of moderate-intensity activity is brisk walking.        If you are already active, additional benefits are possible for most health outcomes if you increase the amount of physical activity by exercising at a higher intensity, more often, or for a longer period of time.        When considering risks versus benefits, the benefits of physical activity outweigh possible adverse outcomes.        Regular exercise, week after week and year after year, is the goal. Maintaining such a program can produce both short-term and long-term benefits. Starting early in life and continuing throughout the lifespan is recommended. In addition to regular aerobic and muscle-strengthening activity, older adults should also incorporate exercises that maintain or improve balance. Unintentional falls affect approximately

30% of older adults each year.4 To help prevent falls, older adults should work on improving strength, balance, and flexibility as well as review medications, which could affect balance. Details on developing age-appropriate exercise plans for older adults are included in chapter 11. Women (Pregnancy and Postpartum) Pregnancy is a time of major changes, including transformations within the body. Healthy women can continue to benefit from physical activity during pregnancy. Pregnant women who have an established regular vigorous physical activity regimen can continue a high level of activity during pregnancy and postpartum provided they remain healthy and work with their health care providers to adjust their activity levels if needed over time.1, 18 Details on physical activity and nutrition during pregnancy are provided in chapter 18. Adults With Disabilities Disabilities, as defined within the Physical Activity Guidelines, include stroke, spinal cord injury, multiple sclerosis, Parkinson’s disease, muscular dystrophy, cerebral palsy, traumatic brain injury, limb amputation, mental illness, intellectual disability, and dementia.18 Although this is a rather broad definition, research supports health benefits for those who are physically active. Recommendations for aerobic activity and muscle-strengthening activities are the same as for adults without disabilities as mentioned previously and further outlined in chapter 10.18 Adults with disabilities who are not able to meet this level of activity should embrace the importance of avoiding inactivity while becoming as regularly active as possible within their ability.18 An appropriate physical activity level should be determined in consultation with a health care provider.18


People With Chronic Medical Conditions People with chronic medical conditions should consult with their health care providers regarding the appropriate types and amounts of activity.18 Chronic medical conditions encompass a wide range of situations, including arthritis, type 2 diabetes, and cancer. Within the limitations of their ability, adults with chronic medical conditions can obtain health benefits from regular physical activity.18


According to the National Institute on Aging, “Together, lack of exercise and poor diet are the second-leading underlying cause of death in the United States.”12 Note that smoking is the number one cause. How empowering to find that improving two lifestyle factors (exercise and nutrition), and avoiding another voluntary behavior (smoking), can have a major impact on your health! In the subsequent chapters, you will learn about exercise as well as nutrition in more detail. The ideal exercise program includes aerobic and muscular fitness activities along with flexibility exercises. Focusing on a balanced nutritional plan will complement your activity program as you seek to improve your health. Whether a zone of “perfect” health exists is arguable. Instead of trying to achieve perfection, focus on how to make small changes each day to continually improve your health. Over time you will reap the rewards!



Leave a Reply

Leave a Reply