The concept that participation in exercise/physical activity reduces the risk for a host of chronic diseases is undisputed. Along with adaptations to habitual activity, each bout of exercise induces beneficial changes that last for a finite period of time, requiring subsequent exercise bouts to sustain the benefits. In this respect, exercise/physical activity is similar to other “medications” and the idea of “Exercise as Medicine” is becoming embedded in the popular lexicon. Like other medications, exercise has an optimal dose and frequency of application specific to each health outcome, as well as interactions with food and other medications. Using the prevention of type-2 diabetes as an exemplar, the application of exercise/physical activity as a medication for metabolic “rehabilitation” is considered in these terms. Some recommendations that are specific to diabetes prevention emerge, showing the process by which exercise can be prescribed to achieve health goals tailored to individual disease prevention outcomes.
Optimizing the Exercise Drug for Metabolic Rehabilitation
Physical Activity Alone May Enhance Health But It May Not Reduce Disability in Chronic Stroke Survivors
In this paper, I argue that physical activity in the form of exercise provides wonderful health benefits for individuals with chronic stroke but fails to also reduce the wider effects of disability for these individuals. The argument proceeds first with a definition of terms, including the classification framework of health and disability according to the World Health Organization. Next follows a section on stroke, its prevalence, and major motor symptoms, including health status. The subsequent two sections include evidence for the health benefits of exercise and lack of evidence for the reduction of disability. The penultimate section expands upon the direction of research that should move us toward reducing disability. The final section concludes on how kinesiology fits into a model for improving both health and reducing disability for chronic stroke survivors.
Physical Activity, Exercise, and the Immune System: Three Lines of Research That Have Driven the Field
Jeffrey A. Woods and Brandt D. Pence
Exercise immunology is a relatively new discipline in the exercise sciences that seeks to understand how exercise affects the immune system and susceptibility to infectious and chronic diseases. This brief review will focus on three major observations that have driven the field to date including: (1) acute exercise-induced leukocytosis, (2) the observation that intense, prolonged exercise results in upper respiratory tract symptoms, and (3) the paradoxical effect of acute and chronic exercise on inflammation. This framework will be used to examine the mechanisms and implications behind these seminal observations. Data generally support the conclusion that moderate intensity exercise enhances immune function, whereas prolonged, intense exercise diminishes immune function.
Physical Activity: Improving Health and Reducing Disability
Philip E. Martin
Physical Activity in the Prevention of Alzheimer's Disease
Jennifer L. Etnier
Alzheimer's disease is a chronic illness characterized by clinical cognitive impairment. A behavioral strategy that is being explored in the prevention of Alzheimer's disease is physical activity. Evidence from randomized controlled trials (RCTs) testing the effects of physical activity for cognitively normal older adults supports that physical activity benefits cognitive performance. Evidence from prospective studies supports a protective effect of physical activity with reductions in the risk of cognitive decline ranging from 28% to 45%. RCTs with cognitively impaired older adults also generally support positive effects with greater benefits evident for aerobic interventions. Research examining the potential moderating role of apolipoprotein E (APOE) has yielded mixed results, but the majority of the studies support that physical activity most benefits those who are at greatest genetic risk of Alzheimer's disease. Future directions for research are considered with an emphasis on the need for additional funding to support this promising area of research.
Physical Activity May Improve Aging Through Impacts on Telomere Biology
Stephen M. Roth
Physical activity has long been touted as a means of reducing susceptibility to age-related disease and multiple studies have shown reduced mortality rates in individuals with a lifestyle including regular exercise. A variety of mechanisms for how physical activity reduces age-related diseases have been explored and multiple, redundant explanatory mechanisms are likely to emerge. Evidence has emerged that physical activity may impact directly on telomere biology, one of the primary theories of cellular aging. Telomeres are located at the ends of chromosomes and as cells divide, incomplete DNA replication results in telomere shortening; once shortening reaches a critical threshold, cell senescence results. Investigators hypothesize that part of the favorable influence of physical activity on mortality rates and age-related disease occurs through a direct impact on telomere biology, including delaying rates of telomere shortening. The present review examines key recent findings in this area and explores some of the unanswered questions and future directions for the field.
A Primer on Exercise Pharmacology
Ira Jacobs, Ethan Ruderman, and Mackenzie McLaughlin
A traditional focus of exercise scientists studying the interaction of drugs and exercise has been on the effects of drugs on exercise performance or functional capacity. In contrast, there is limited information available about the effects of exercise on the efficacy of drugs that have been prescribed and ingested for therapeutic reasons. Those requesting the approval for the manufacture, distribution, and sale of new drugs to the public are required to submit evidence of drug effectiveness and safety to drug regulatory bodies. But, there is no associated requirement to include among that evidence the interactions of exercise with drugs. However, the physiological adaptations to acute and chronic exercise are such that there is good reason to suspect that exercise has the potential to significantly influence drug absorption and bioavailability, drug distribution within the body, and drug elimination from the body. This paper reviews the potential for interaction between exercise and pharmacokinetics.
School Environment and its Effects on Physical Activity
School is an environment where children and adolescents spend most of their time during the day. The environment is characterized by a sedentary culture necessary for academic learning. In this article, I present research evidence showing the effects of four physical activity opportunities in this environment: school athletics, recess, classroom physical activity breaks, and physical education. Based on an analysis of research evidence on the four opportunities, I propose that the efforts to promote the opportunities should be coordinated into a concerted action to integrate a physical activity-friendly culture in the sedentary environment. Using an example of China's whole-school physical activity promotion strategy, I identify four areas for us to continue to work on: legislature-based policies, physical education as core content, creation and maintenance of physical activity traditions in schools, and integration of physical activity-friendly culture into the sedentary school environment.
The Utilization of Biomechanics to Understand and Manage the Acute and Long-term Effects of Concussion
Jay L. Alberts and Susan M. Linder
The acute and long-term effects of concussive and subconcussive head impacts on brain health have gained tremendous attention over the past five years. The treatment and management of concussion involves multiple providers from multiple disciplines and backgrounds. Varied backgrounds and approaches to assessing cognitive and motor function before and post-concussion are limiting factors in the efficient and effective management of concussion as discipline-specific rating scales and assessments serve as a barrier to effective patient hand-offs between providers. Combining principles of motor behavior with biomechanical approaches to data analysis has the potential to improve the continuity of care across the multiple providers managing athletes with concussion. Biomechanical measures have been developed and validated using mobile devices to provide objective and quantitative assessments of information processing, working memory, set switching, and postural stability. These biomechanical outcomes are integral to a clinical management algorithm, the Concussion Care Path, currently used across the Cleveland Clinic Health System. The objective outcomes provide a common data set that all providers in the spectrum of care can access which facilitates communication and the practice of medicine and in understanding the acute and long-term effects of concussion and subconcussive exposure on neurological function.