The Institute of Medicine’s New Recommendations on Youth Fitness Measures and Health Outcomes
The American College of Sports Medicine’s weekly newsletter, Sports Medicine Bulletin (SMB), conducted an interview with Dr. Russell R. Pate regarding the Institute of Medicine’s (IOM) new recommendations on youth fitness measures and health outcomes. As reported in a recent IOM news release, techniques ranging from running to push-ups to sit-and-reach tests have been used to measure various aspects of fitness in children and adults. However, evidence is sparse on how well some of these techniques correspond to desired health outcomes in children, fueling debate about the best fitness measures for youth.
Fitness testing has traditionally focused on four aspects: heart and lung function, body composition, muscular and skeletal fitness, and flexibility.
A committee convened by the Institute of Medicine undertook a comprehensive review of the science and found that it supports the use of specific ways to measure three of these components — cardiorespiratory endurance, body composition, and musculoskeletal fitness — in young people. These measurements should be used in national youth fitness surveys and school-based fitness tests, says the committee’s report.
Dr. Pate served as chair of the Institute of Medicine committee that was charged with developing new science-based recommendations on physical fitness testing as a means of addressing health needs of American youth.
These IOM recommendations, published under the title Fitness Measures and Health Outcomes in Youth, were released late in 2012. Dr. Pate kindly accepted SMB’s invitation to do this Q&A, sharing his views on the purpose of these new recommendations, the key elements, and their potential to help combat childhood obesity.
SMB: Youth fitness testing has been an integral part of physical education programs in our schools for many decades. What are the limitations in tests currently used and what led the IOM to develop these new recommendations?
Pate: The IOM report was prompted by the need to identify test items that would be appropriate for inclusion in a national survey of physical fitness in American youth. Such surveys were conducted in every decade between the 1950s and 1980s, but no national survey has been undertaken since then. A survey of modest scale is currently being conducted by the U.S. Centers for Disease Control and Prevention under the auspices of the National Health and Nutrition Examination Survey (NHANES). It is hoped that a large scale, field-based survey will be conducted before the end of the current decade. The IOM panel was charged with recommending valid test items, performance on which has been shown to be related to health characteristics in youth. Previous test batteries for use in schools and in surveys have comprised valid measures of fitness components that are known to be health-related, usually based on evidence in adults. The IOM panel’s job was distinct in that recommended test items were required to be health-related in youth. The panel found that such evidence was lacking for some test items that have been widely used as measures of fitness in young people.
SMB: The IOM is a nonprofit entity that is part of the National Academies and provides independent expert advice to the government and other organizations on matters of importance to the health of Americans. What is your impression of the process that IOM used to develop these recommendations on youth fitness testing? How did that process influence the product of your committee’s work?
Pate: The IOM has established a very careful and rigorous process for developing its reports. That process is grounded in scientific rigor, objectivity and avoidance of conflict of interest. The report of this IOM panel clearly reflects those standards in that its recommendations are tightly linked to the available scientific evidence. The CDC supported the panel’s work by conducting a very extensive literature review. The product of that review was the primary source of scientific information used by the panel, although in some cases additional references were used. Based on my personal experience with this issue, I believe that the process followed by the panel is the most scientifically rigorous review of fitness measures for youth performed to date. While the panel recommendations were tightly linked to the scientific evidence, I believe the panel worked very diligently to acknowledge the perspective of teachers who often adopt educational objectives that extend beyond issues of test-item validity.
SMB: Based on the science your committee examined, what did you find to be the best health-related measures for tracking health aspects of fitness with American youth? If different that currently practiced, are the recommended measures feasible and affordable for our schools to adopt?
Pate: The committee found that the progressive shuttle run test (sometimes referred to as “The Pacer” test) is a valid measure of cardiorespiratory endurance and that substantial evidence shows that performance on this test is related to children’s cardiometabolic risk status. This test has the additional advantages of already being in wide use in schools and is known to be well accepted by kids. For measurement of body composition the committee recommended use of three measures: body mass index; skinfold thicknesses, and waist circumference. Each has been widely used in surveillance studies, and each provides somewhat unique information about the relationship between weight status and cardiometabolic risk status. Musculoskeletal fitness, the committee recommended, should be measured via grip strength and standing long jump measures, both of which have been used effectively in studies linking musculoskeletal fitness to bone health. For application in educational settings, as distinct from large scale surveys, the committee recommended the progressive shuttle run, body mass index, grip strength and standing long jump items. Several other measures were recognized as acceptable for use in educational settings even though associations with health outcomes are not well established.
SMB: What important knowledge gaps did your committee find in the literature, if any? Related to that question, what targeted research is needed to lead us to more relevant health-fitness testing for youth?
Pate: The committee found many limitations in the scientific evidence addressing the relationship between measures of health-related fitness and health characteristics in youth. In particular, the committee noted the need for more longitudinal studies, using both experimental and observational study designs, evaluating the relationships between change in performance on fitness measures and change in markers of health. Clearly, we need to know more about how children’s health is influenced when their physical fitness is modified by changes in their physical activity.