Associate Professor TSUNODA Kenji, Institute of Health and Sport Sciences

In the center of Tsukuba City, home to the University of Tsukuba, various areas are connected by pedestrian and bicycle lanes (also known as pedestrian decks or pede). These lanes also connect to the university campus, which enables students to commute from Tsukuba station to the campus using the pede. Many faculty members ride bicycles, and Professor TSUNODA himself rides his bicycle for a distance of approximately 5 km from his home to the university every day. "Tsukuba has few hills, and pedestrian decks are well-maintained, which makes riding a bicycle easy. As traffic is not congested, it is very comfortable," he says.

These Kuroshio cyclones travel eastward along the southern coast of Honshu, Japan's main island, often bringing heavy snowfall or rainfall to the densely populated Pacific side of the country. In February 2014, two such systems struck in rapid succession. The second event, in particular, caused record-breaking snowfall—114 cm in Kofu City and 73 cm in Maebashi City—highlighting the severe impact of these cyclones.

Professor TSUNODA's research, which began in 2013, focuses on the correlation between healthy longevity and bicycle use among older adults. Questionnaires on bicycle use were mailed to older adults living in Kasama City, Ibaraki Prefecture, and 6,385 valid responses were collected (average age: 74.2, 52.5% women). The researcher followed these respondents for up for 10 years until 2023.

Analysis revealed that aged individuals who used bicycles for even short periods in 2013 exhibited lower risks of requiring long-term care (classified as Level 1 or higher under the long-term care certification system of the government) and mortality over the subsequent 10 years compared with nonusers. Furthermore, reduction in both risks was particularly pronounced among nondrivers of cars (Figure 1).

Professor TSUNODA and colleagues conducted an additional survey in 2017. Among the valid respondents in 2013, they mailed questionnaires to elderly individuals who were alive in 2017 and reported no history of long-term care certification or relocation outside Kasama City. The authors received valid responses from 3,558 individuals. They then classified the respondents into four groups based on bicycle usage status in 2013 and 2017, namely, "nonusers," "started using," "stopped using," and "continued using" (with a minimum of one day per week as the criterion). A six-year follow-up survey was then conducted until 2023 to examine the incidence of long-term care needs and mortality.

The results demonstrated that among the respondents who continued using bicycles from 2013 to 2017, the risk of developing long-term care needs and mortality across the subsequent six years was lower compared with that of nonusers. Furthermore, in an analysis limited to nondrivers of cars, those who continued to use bicycles and those who started using bicycles displayed low risks of requiring long-term care (Figure 2).

Professor TSUNODA says, "These results imply that bicycle use among the elderly contributes to the extension of a healthy life expectancy and overall life expectancy, with the effect being particularly significant among people who do not drive cars."

Professor TSUNODA initially intended to conduct research on scientific weight loss methods in graduate school, as he had struggled with weight loss while he was a member of the judo club at Tokyo Gakugei University. However, he reflected that "my research theme changed while helping out at exercise classes in Kasama City."

In recent years, the number of older adults who returned their driver's licenses has been increasing, but securing alternative means of transportation has also emerged as a major issue. Many older adults suffer from knee pain, while cycling exerts less impact on the knees compared with walking and enables them to travel longer distances. Increased social interaction outside the home can also improve mental health and promote physical well-being. According to the literature, older adults in Japan use bicycles compared with those in other developed countries. Professor TSUNODA points out, "Bicycle use poses significant advantages for elderly people living in mountainous areas with limited transportation options. Social support is required to promote bicycle use among the elderly, including measures to ensure traffic safety."

Article by Science Communicator at the Bureau of Public Relations