If you've never heard of a kendama, you might be surprised to learn it's not just a children's toy. Originally a traditional Japanese skill toy, kendama has evolved into a modern competitive sport with deep roots in action sports culture, sitting comfortably alongside skateboarding, BMX, and scootering. It shares the same creative flow, technical skill, and personal style that define those communities, and it has built its own passionate global following as a result.
Which makes the findings of a 2024 study published in the Japanese Journal of Comprehensive Rehabilitation Science all the more interesting. Because it turns out that the same qualities that make kendama compelling to a 14-year-old skater also make it surprisingly effective for a 70-year-old looking to stay sharp and mobile. The researchers put that idea to the test, and the results are worth paying attention to.
What Is a Kendama?
A kendama is a wooden skill toy consisting of a handle (the "ken") with a small spike on top, and a ball (the "tama") attached by a string. The goal is to swing the ball and catch it on the cup or spike in various combinations of tricks. It demands hand-eye coordination, focus, balance, and repetitive physical movement, which turns out to be a pretty powerful combination for aging bodies and brains.
The Study
Researchers Watanabe, Hirowatari, and colleagues recruited 17 community-dwelling adults aged 65 and over for a 30-day kendama program. Participants practiced kendama in groups once a week for four sessions, and individually for at least 20 minutes a day over the course of 30 days. The goal was to explore whether kendama could serve as a practical way to reduce the risk of two major concerns in aging populations: dementia and musculoskeletal disorders.
The Results
Stronger Legs
One of the standout physical findings was how much leg strength improved in just one month. Knee extension muscle strength increased significantly by 18.8% after the intervention. That's a meaningful gain. Knee strength is closely tied to fall prevention and overall mobility in older adults, and losing it is one of the key contributors to loss of independence.
A Sharper Mind
The cognitive results were equally striking across three separate tests. The time required to perform the Stroop test decreased by 10.1%, the number of Symbol Digit Modalities Tests completed increased by 5.6%, and the number of correct answers in the word memory test increased by 17.8%, all statistically significant improvements. These tests measure processing speed, attention, and memory, which are the very functions most vulnerable to age-related decline and early dementia.
Thirty days of playing with a toy produced measurable improvements across multiple cognitive domains. That's not something you'd expect going in.
Why Does It Work?
Kendama isn't passive entertainment. Every trick requires the player to track a moving object, time their movements precisely, and coordinate their hands, eyes, and body together. This kind of motor-cognitive challenge, where physical movement and mental attention are happening at the same time, is well-recognized in rehabilitation science as a powerful stimulus for brain health.
The repetitive squatting and weight-shifting involved in kendama play also activate the leg muscles in a functional, low-impact way that doesn't feel like exercise, which matters enormously for whether people actually stick with it.
The Social Side
Perhaps as importantly, the study suggested that kendama can be enjoyed easily and is expected to be practiced continuously with friends. Group practice sessions gave participants a reason to come together regularly, adding a social dimension that solo exercise programs often miss. Social engagement is itself a protective factor against cognitive decline, so kendama ends up doing double duty there.
A Few Caveats
The study was small, just 17 participants, and lacked a control group, so the findings shouldn't be overstated. About 30% of participants also reported that the frequency of individual practice was "a little too much," suggesting the daily 20-minute solo sessions may need to be adjusted in future programs. The researchers acknowledged these limitations and called for further study.
The Bottom Line
Kendama won't replace walking, strength training, or a healthy diet. But as a fun, social, low-cost activity that challenges both the body and the brain at once, it has real potential as a complement to existing healthy aging programs. The researchers concluded that kendama can serve as an exercise program for reducing the risk of dementia and musculoskeletal disorders.
At under $30 for a quality beginner's kendama, the barrier to entry is pretty low. It might be worth trying, regardless of your age.
Study from: https://pmc.ncbi.nlm.nih.gov/articles/PMC11519782/