Sport, health and physical education, and exercise science professionals are commonly asked: “How much exercise training is enough? Are the benefits worth the cost and risks? Is life expectancy extended with exercise?”
The list is endless and there are no simple answers. Obesity in America and living room technology are on the rise, while government funding for physical education is declining. The global outlook for large-scale physical activity is uncertain.
It is well-known that a minimum of 30 minutes per day of moderate intensity exercise in children and adults is beneficial for health (JAMA, 1996). A recent review of 104 physical activity questionnaires and 1965 exercise items by Williams et al. (2012) found that no questionnaires covered all types of physical activity categories. This illustrates how categorizing exercise into a one-size-fits-all package is difficult and involves activity identification, quantification, multi-level analysis and evaluation.
The answer for “How much exercise training is enough?” is therefore, “It depends.” The amount depends on the population, activity, assessment instrument, and outcome criteria. For example, enjoyment of activities with family, friends, or at school requires up to a well-rounded amount. If the goal is to enjoy a sport, then a mild to moderate amount will do. To compete or be the best at a sport, and in particular a high power output sport, a higher-intensity risk-reward balance exists between success or failure (including injuries). If there is no exercise training then the enjoyment and performance of sport, physical activity and quality of life will decline, while elevating the risk of health-related diseases.
If exercise is healthy and relatively inexpensive, then why are fewer Americans exercising? One possibility is that technology has replaced much of the physical activity at home, play and work. As the current generation of family role models grows and develops in a high-tech world, less emphasis is placed on physical activity with large muscle groups. More time with personal, social and occupational technology (e.g. computer, cell phone, texting, video games and television) burns fewer calories versus physical activity. A progressive reduction in calorie burning with technology use eventually leads to weight gain and a higher risk of obesity with related complications.
One solution is to set, assess, and update achievable and progressive physical activity goals. An example would be a goal per day, then per week and beyond. A small achievable goal could be parking farther from the store for a 2 to 3 minute walk to the entrance. The second week could be the same accompanied by a brisk walk. Another would be walking or other exercise during the lunch hour followed by a glass of juice or water instead of no exercise, fast food and relaxing. Trimming the waistline, and improving zip in sport and daily activities, work production, and quality of life are achievable with minimal effort and expense in a technology world.
Dr. William W. Edwards, PhD, is the Chair of Sports Exercise Science at the United States Sports Academy. He has competed in road races and triathlons for over 20 years and worked with K-12, adult fitness, high-risk, and rehabilitation populations. He can be reached at firstname.lastname@example.org.
NIH Consensus Development Panel on Physical Activity and Cardiovascular Health (1996). Physical activity and cardiovascular health. JAMA, 276, 241–246.
Williams, K., Frei, A., Vetsch, A., Dobbels, F., Puhan, M.A., & Rüdell, K. (2012). Patient-reported physical activity questionnaires: A systematic review of content and format. Health and Quality of Life Outcomes, 10 (28), 1-18.