“Sportology:” A new field of study that uses physical activity to understand health
The Sportology Center was founded to integrate medicine and sports, advancing research focused on preventing lifestyle-related diseases caused by overnutrition and physical inactivity as well as mitigating underlying conditions that can lead to the need for long-term care. We spoke with Director Ryuzo Kawamori, who coined the concept of “sportology,” about the center’s initiatives, ranging from detailed measurement of physical activity to large-scale cohort studies.
Sportology is not merely sports medicine, but a new academic discipline that seeks to deepen and integrate multiple related fields with physical activity as its central focus.
Established in 2007, the Sportology Center drives research by integrating cutting-edge knowledge from basic and clinical medicine, including fields such as philosophy and neuroscience. This interdisciplinary approach allows the Center to establish a new academic foundation, contributing to both disease prevention and the development of medical treatments.
Research teams from diverse health-related disciplines collaborate to address the complex challenges associated with extending healthy life expectancy, including issues such as fatty muscle and fatty liver in non-obese individuals, cognitive function, locomotive syndrome, and health concerns among underweight women. The Center also conducts unique research on a global scale, such as the Bunkyo Health Study, which comprehensively assesses the health status of older adults and follows them longitudinally to develop effective intervention strategies.
A hallmark of this research is its focus not on individuals already affected by disease, but on those who appear healthy. The physical condition of each participant is precisely measured from multiple perspectives to identify factors that contribute to maintaining health and the onset of disease.
The Sportology Center’s motto is “Measure all that can be measured by humans, and use ingenuity to measure what cannot.” This approach allows researchers to identify critical health-related factors and disease precursors that were previously assessed only by appearance.
To support this line of work, the Center is equipped with a wide range of advanced measurement instruments, such as MRI and MRS machines for precise assessment of whole-body composition and brain structure, a dual-energy X-ray absorptiometry device for bone mass measurements, and a multipurpose exercise device for evaluating muscle function and strength. Other examples include an artificial pancreatic islet for quantitatively assessing insulin-stimulated muscle glucose uptake and hepatic glucose disposal and a human calorimeter chamber system for monitoring energy metabolism. The chamber simulates a real-life environment, complete with a bed and toilet, allowing participants to live there for 24 hours while eating, sleeping, and exercising as usual. This setup enables minute-by-minute measurement of energy metabolism during sleep, exercise, and meals.
By fully utilizing these instruments, researchers have discovered that even non-obese adult men with normal health checkup results could have fatty liver, fatty muscles, and reduced insulin-stimulated glucose disposal in the liver and muscles. These conditions were linked to decreased physical activity and excessive fat intake. This finding received widespread media coverage, popularizing the term “lean metabolic syndrome” to describe a high risk of lifestyle-related diseases associated with elevated visceral fat, even in individuals who appear thin.
The first core program of the Center—the Sportology Center Core Study—was designed to shed light on the pathologies of metabolic and vascular disorders seen in metabolic syndromes and diabetes in non-obese individuals. These conditions are commonly observed in Japan and many countries in East Asia.
Research has shown that, even in non-obese individuals, the accumulation of ectopic fat in insulin-sensitive organs such as the liver and skeletal muscle impairs insulin action and raises blood glucose levels. Asians are particularly susceptible to fatty liver even at a low body weight. Consequently, a study was conducted on non-obese Japanese individuals to examine the relationship between insulin resistance, metabolic abnormalities, and ectopic fat accumulation, yielding a series of important findings.
“For instance, skeletal muscle insulin resistance plays a key role in the development of metabolic syndrome and diabetes, while heavy alcohol consumption contributes to hepatic insulin resistance and elevated fasting blood glucose levels,” explains Dr. Kawamori. It is also known that endurance athletes can maintain high performance despite elevated lipid accumulation in their skeletal muscles—a phenomenon known as the “athlete’s paradox”—which has been linked to differences in fatty acid transporters within the muscles.
In addition to these findings and detailed biochemical profiles, the Center leverages its unique comprehensive lipidome data from blood and skeletal muscle, as well as genetic information. These enable researchers to reach new insights to inform personalized medicine and effective interventions for Japanese and East Asian populations.
The second core program—the Bunkyo Health Study—is a cohort study involving 1,629 older adults. It aims to determine when, why, and in whom declines in cognitive and motor function begin, as well as how these changes can be detected and prevented at an early stage. The Bunkyo Health Study is distinguished by both its large participant base and its exceptionally wide range of survey measures; such a large-scale cohort study is unparalleled worldwide.
Specifically, the study enrolled 1,629 randomly selected older adults aged 65 to less than 85 living in Bunkyo Ward and conducted comprehensive assessments of skeletal muscle mass, insulin-stimulated glucose uptake, cognitive function, brain MRI, arteriosclerosis, joint function, genetic polymorphisms, and lifestyle factors such as physical activity and diet. Since its inception, annual mailed questionnaires have been distributed, and in-person assessments—including MRI scans—have been conducted every five years since 2020, resulting in a follow-up period exceeding 10 years.
The Bunkyo Health Study produced numerous insights into the motor and cognitive functions of older adults. For example, it examined the relationship between knee changes, pain, and motor function. About 60% of participants showed early signs of knee osteoarthritis (OA). However, those with advanced knee OA exhibited reduced motor and cognitive functions and worsened metabolic syndrome-related factors compared to individuals in the early OA group.
A particularly significant finding is that exercise habits in youth directly shape physical function in later life. “Elderly individuals who were active both during middle and high school, as well as in old age, showed a lower risk of sarcopenia and preserved muscle function,” says Dr. Kawamori. Women with this lifelong exercise pattern also had higher bone density and a reduced risk of osteoporosis. These results are especially relevant for younger generations, which will likely enjoy a 100-year life span. Thus, it is essential to encourage elementary, junior high, and high school students to establish regular exercise habits through club activities and other opportunities.
The third core program—the Underweight Women Study—seeks to assess the current health status of Japanese women, identify the latent disease risks and underlying causes in underweight individuals, and develop tailored intervention strategies.
Japan has the highest prevalence of underweight women among developed countries, with one in eight women and more than one in five young women classified as underweight. Underweight women are known to face an increased risk of osteoporosis, falls, and fractures, and considerable research has examined the relationship between low body weight and bone health. Conversely, studies in Japan have reported that both underweight and obese women face a high risk of developing diabetes. However, the reasons why thin women are particularly susceptible remain largely unclear.
The Underweight Women Study focused primarily on tall, underweight young women in their 20s and underweight postmenopausal women aged 50 to 65. Participants underwent glucose tolerance tests to assess diabetes risk, bone mass measurements, and ectopic fat evaluations (fatty liver and fatty muscle). The results revealed that underweight young women had a significantly higher prevalence of impaired glucose tolerance compared to normal-weight individuals. This could be related to a “low-energy turnover” pattern characterized by low food intake and physical inactivity, which may be influenced by reduced skeletal muscle mass.
Following the announcement of this study, it was selected for inclusion in the Cabinet Office’s SIP Phase 3 project, “Building an Inclusive Community Platform,” under the initiative “Research and Development for Improving Women’s Body Image and Health,” launching a five-year research and development program in April 2023. In Japan, the societal bias equating “underweightness” with beauty is believed to contribute to underweight prevalence among young women and associated health issues. This research aims to promote inclusivity regarding body shape across society, with the goal of enabling women to live healthy lives both physically and mentally.
Director, Sportology Center, Juntendo University Graduate School of Medicine
Dr. Kawamori graduated from Osaka University School of Medicine in 1968. In 1971, he joined the University of Toronto and later served as a lecturer in the First Department of Internal Medicine at Osaka University School of Medicine. In 1994, he became a professor of metabolism and endocrinology at Juntendo University School of Medicine, and has served as Director of the Sportology Center since 2008. He also serves as a specially appointed professor at Juntendo University Graduate School of Medicine and as an Adjunct Full Professor in the Department of Physiology & Medicine at the University of Toronto. His expertise lies in metabolism and endocrinology. His hypothesis, which states that “disease symptoms emerge only when the connections between the brain, muscles, liver, heart, and joints cease to function properly,” is increasingly being supported by research at the Sportology Center.