This review examines the relationship between physical activity and cancer along the cancer continuum, and serves as a synthesis of systematic and meta-analytic reviews conducted to date. There exists a large body of epidemiologic evidence that conclude those who participate in higher levels of physical activity have a reduced likelihood of developing a variety of cancers compared to those who engage in lower levels of physical activity.
Despite this observational evidence, the causal pathway underling the association between participation in physical activity and cancer risk reduction remains unclear.
Physical activity is also a useful adjunct to improve the deleterious sequelae experienced during cancer treatment. These deleterious sequelae may include fatigue, muscular weakness, deteriorated functional capacity, including many others. The benefits of physical activity during cancer treatment are similar to those experienced after treatment. Despite the growing volume of literature examining physical activity and cancer across the cancer continuum, a number of research gaps exist.
There is little evidence on the safety of physical activity among all cancer survivors, as most trials have selectively recruited participants. It is also unclear the specific dose of exercise needed that is optimal for primary cancer prevention or symptom control during and after cancer treatment. Cancer is the leading cause of death in cts and diabetes countries and the second leading cause of death in low- and middle-income countries.
Approximately 1 in 4 deaths in the United States are due to cancer This growing population of cancer survivors has emerged from improvements in screening and detection, as well as improvements in a variety of treatment modalities, including, surgery, chemotherapy, and radiation therapy Despite the success of procedures to identify and control cancer once detected, primary prevention of cancer is an area of great interest on many levels including exercise and fitness impact on cancer, economic, and political.
Despite the genetic hallmarks of cancer, lifestyle and environmental variables are pivotal influences in the development of cancer Identifying lifestyle and environmental risk factors associated with developing cancer, educating the public about these risk factors, and providing interventions to modify the exposure to these risk factors may provide a viable route to decrease the burden of cancer.
Numerous risk factors associated with developing cancer have emerged including, sexual behavior, addictive substances, and factors including overweight and obesity, low fruit and vegetable intake, and physical inactivity.
Overweight, obesity, and physical inactivity contribute to the risk of developing a number of cancers. Though overweight and obesity may appear to be separate from physical activity, both constructs relate to energy balance Maintaining an optimal level of energy balance—caloric expenditure relative to caloric intake—is associated with primary prevention of cancer, survival after diagnosis and recurrence of primary cancer 97 Therefore, it is necessary to acknowledge the synergistic relationship between overweight or obesity and physical inactivity along the spectrum of cancer prevention and survivorship 68 More generally, of the 7-million deaths that occurred from cancer worldwide inan estimated 2.
There also exists a depth and breadth of literature examining the independent effects of physical activity along the cancer continuum. To this end, we acknowledge the synergistic relationship among obesity, physical activity, and energy balance; however, we choose to focus our review on the independent effects of physical activity, rather than the overarching influence of energy balance. To critically analyze and interpret the results from any scientific study, it is important to understand the methodological characteristics associated with a particular investigation, including study design, methods of assessment and quantification of physical activity, and appropriate conduct and interpretation of statistical analyses.
In the ensuing paragraphs, we define physical activity, how back pain and rheumatoid arthritis measure and quantify physical activity, and we briefly review two common study designs used in the assessment of physical activity and the risk of cancer.
Physical activity is any movement using skeletal muscles Physical activity can be categorized into four major subgroups. Physical activity can also be of varying biaxin and numbness, including light, moderate, and vigorous intensity Examples of activities with light, exercise and fitness impact on cancer, moderate, and vigorous intensities include housework, brisk walking, and running, exercise and fitness impact on cancer, respectively 2.
The most common method of ascertainment of physical activity is exercise and fitness impact on cancer the use of self-report measures. The popular method of subjective physical activity estimation is with the use of physical activity questionnaires There are over two-dozen physical activity questionnaires that demonstrate validity and reliability—the ability to quantify a variable of interest and to quantify the variable repeatedly among a large sample of participants.
Physical activity questionnaires vary in the complexity of questions asked, time needed to complete, and the type and dose of physical activity measured.
For a compendium of over physical activity questionnaires, we refer the reader to the National Cancer Institute physical activity questionnaire website To assess physical activity, there are four parameters that may be estimated: Intensity is how strenuous or how physically demanding a single bout of physical activity is.
Type is the modality of physical activity, and frequently includes aerobic, strength and flexibility activities. However, from an epidemiologic perspective, modality includes broad categories such as occupational, leisure-time, or personal-care physical activities.
It is these four components, frequency, intensity, time, and type that form the foundation of physical activity or exercise prescription, referred to as the FITT principle frequency, intensity, time, type ; The two most common study designs used to examine the association between physical activity and risk of cancer are the cohort and case-control study. Each of these observational study designs is subject to methodological strengths and weaknesses. We refer the reader to two excellent reviews comparing cohort and case-control studies and the interpretation of statistical analyses and conclusions from each study design 28 Despite this exciting time, the etiology of cancer has provided numerous challenges to conduct high-quality research.
For example, the growth and development of cancer may take decades to occur. This long latent period makes the study of physical activity and cancer research difficult. The spectrum from cancer prevention to palliative end-of-life care encapsulates many decades of life. The population of cancer survivors has grown to include approximately million in the United States, and million worldwide 75 This makes the identification and assembly of a population of cancer survivors difficult for research endeavors.
The multifactorial exercise and fitness impact on cancer of cancer, long latent period, and relatively small population influence the research design used in physical activity or exercise and cancer what we refer to as. For continued success in exercise oncology research, three corner stones must exist Figure 1. The paradigm of exercise oncology research is similar to the paradigm originally proposed by Henry Blackburn much more generally for multiple areas of biomedical research 9and posits that human clinical trials, observational trials, and basic bench science trials should not be considered discrete components of research, but more as parts of a continuum.
The paradigm of exercise oncology suggests observational trials may generate hypotheses to be tested, manipulated, and explored in animal models, and then translated into human clinical trials. We remind the reader this example, is exactly that, an child behavior assessment plan and treatment. One might begin with an animal model or human clinical trial, and traverse the paradigm.
Another critical component to the success of physical activity and cancer research is the integration of policy reform, economic analysis, outreach, and dissemination. One or more of these components may occur after conduct of a methodologically rigorous human clinical trial. According to Sporn et al. Despite the importance of physical activity in the primary prevention of cancer, physical activity is also a modality with the capacity to provide health-benefits after diagnosis of cancer.
Participation in physical activity has emerged as a potent rehabilitative modality for cancer survivors in the past 20 years Physical activity has numerous documented health-benefits among cancer survivors, including improved disease-free survival, muscular strength, aerobic capacity, and quality of life. An organizational model exists to delineate the role of physical activity across the continuum of cancer control, including the major subsets prior to and after diagnosis of cancer Figure 2 ; Within the two major subsets of diagnosis, there exist six distinct periods including eight total outcomes that are applicable to physical activity and cancer We will use this conceptual model to guide us through the role of physical activity and the cancer survivorship continuum.
A conceptual model to guide and organize the role of physical activity across the cancer control continuum. Reproduced with permission from Over the previous two decades, major improvements have been made in our ability to detect, exercise and fitness impact on cancer, diagnose, treat, exercise and fitness impact on cancer, and in some cases, cure cancer.
Given this evolution, patients may die withexercise and fitness impact on cancer, rather than from some forms of cancer. Despite this, the ultimate goal of exercise and fitness impact on cancer oncology care clinicians and cancer centers around the world is to eradicate cancer as a cause for human suffering—a goal we have not yet reached.
Nonetheless, our investment in working towards this goal has uncovered encouraging research relating to behavioral components of health that may influence the continuum of cancer. Evidence of physical activity has emerged in a variety of forms—animal models, observational, and randomized controlled trials—to influence an exercise and fitness impact on cancer of cancer outcomes.
However, providing patient care includes numerous competing demands. Therefore, it is unrealistic to expect cancer care clinicians to stay abreast of all the rapidly developing literature relating to cancer pathology, treatment modalities, and physical activity and rehabilitation.
Therefore, the goal of this review is to provide an overview of the benefits associated with physical activity across the cancer continuum. We aim to delineate the efficacy of physical activity and identify the need for exercise physiologists trained with the knowledge, exercise and fitness impact on cancer, skills, and abilities necessary to provide safe and efficacious exercise prescriptions exercise and fitness impact on cancer cancer survivors, exercise and fitness impact on cancer.
This will allow the oncology care clinicians to focus their time on patient care and treatment, and facilitate referral to available exercise physiologists if such care is necessary. The interest in pursuing careers in exercise physiology has grown dramatically in the previous years Moreover, an evidence base of great depth and breadth celebrex and side effects emerged that suggests physical activity provides numerous heart healthy benefits.
Analogous to the spectrum of cardiovascular physiology and cardiac rehabilitation, cancer physiology has emerged along a similar paradigm, exercise and fitness impact on cancer. Despite a considerably smaller foundation of evidence, the current depth and breadth of evidence is promising—supporting the role of physical activity along the cancer continuum.
Though similarities between cardiac rehabilitation and cancer rehabilitation exist, there are also many differences. Academic training in exercise physiology foci include emphasis on cardiopulmonary parameters of rehabilitation and exercise training i. However, cancer rehabilitation requires knowledge beyond that of cardiovascular physiology.
Cancer and cancer treatment affects musculoskeletal, nervous, immune, endocrine, and cognitive systems, in addition to the cardiopulmonary systems described above It is our hope that this review will serve as the bridge from crestor and bladder problems exercise physiology to clinical exercise physiology by providing a foundation of knowledge to build upon, for those interested in learning more about the role of physical activity along the cancer continuum.
This section provides a summary of the epidemiologic evidence of physical activity and primary cancer prevention. Due to the extensive depth and breadth of the epidemiologic evidence concerning primary cancer prevention, this section cannot provide an exhaustive review of all relevant literature.
This section will serve as a brief synthesis of the most recent published systematic or meta-analytic reviews 36515262, Population-attributable-fraction is an estimate of the proportion of reduction in cancer that would occur if exposure to a certain risk factor i. It is of interest to modify unfavorable risk factors that increase ones risk for developing cancer. Primary prevention through behavioral and environmental modification is a cost-effective means of preventing the large burden cancer has on societies worldwide Individual risk factor contributions to mortality from all cancers, worldwide.
Breast cancer incidence varies geographically; likely related to the numerous risk factors, exercise and fitness impact on cancer, such as the reproductive and hormonal milieu, alcohol consumption, exercise and fitness impact on cancer, obesity, and physical inactivity; factors contingent on culture, lifestyle, and environmental exercise and fitness impact on cancer There have been over 73 observational studies that examine the association between breast cancer and physical activity 51 However, the magnitude of the reduction in breast cancer risk was different between study designs.
The magnitude of breast cancer risk-reduction does not increase proportionally with larger volumes of physical activity. Volume of physical activity with levels including cancer diagnosis and wishing someone well. It is unclear why 4.
It is plausible that an insufficient number of studies have examined a dose of physical activity falling in the range of 4. Most studies have favored examining extremes of physical activity dose in attempt to answer the questions: