鍛鍊身體對大腦有益

Everyday physical activity, like going for a short walk or playing with the kids, may provide short-term benefits for cognitive health, equivalent to reversing four years of cognitive aging. That was a key finding for my colleagues and me in our new study, which was published in the journal Annals of Behavioral Medicine.
你的日常活動強度無須劇烈，就能夠逆轉好幾年的認知力老化(《Annals of Behavioral Medicine》文章)。

Prior to enrollment into a study of diet and dementia risk, we asked a diverse sample of 204 middle-aged adults to check in five times per day for a period of nine days, via a smartphone application.
204位中年人9天內用智能手機App每天5次登記自己狀況。

Each check-in involved completing a brief survey that asked about their mood, dietary choices and whether they engaged in any physical activity in the roughly three and a half hours leading up to the survey. In addition, participants completed a few brief brain games – meaning performance-based cognitive assessments that lasted about one minute each – to assess mental speed and short-term memory. 調查內容包括情緒、飲食、活動，另外參加幾次認知評估。

My team found that performance on our measure of cognitive processing speed improved during check-ins when participants reported being physically active in the time leading up to the survey. While we didn’t see improvements in our measure of working memory, the time taken to complete the memory task mirrored what we saw for the measure of processing speed. Jonathan G. Hakun教授的研究團隊發現，身體鍛鍊對於改善大腦反應速度有幫助，而對改善記憶沒有幫助。

We observed these improvements in speed regardless of whether the activity was lighter intensity or moderate-to-vigorous intensity. This led us to conclude that movement, whether it took the form of intentional exercise or part of a daily routine, was the essential ingredient for achieving this benefit.
這些改善與身體鍛鍊的強度無關。

As a rule, we get slower, both physically and mentally, as we age. While research on exercise and living a healthy lifestyle has demonstrated the long-term cognitive and brain health benefits of remaining physically active, much of this work has focused on the moderate- to vigorous-intensity physical activity – or what most of us think of as exercise – recommended by the Physical Activity Guidelines for Americans. 人的身體和智力會越老越遲鈍。過去的研究大多集中在中、高強度的身體鍛鍊，認識到是對大腦健康有益。

Still, these guidelines and other experts recommend that adults move more and sit less. 《美國人身體活動指南》建議成年人多運動，少坐。

My colleagues and I are interested in understanding how moving more can improve our cognitive health or reduce our risk of dementia as we age, at what timescale these benefits show up, and what types of movement qualify. 為何多運動能改善大腦健康？需要鍛鍊多久才會看到好處？哪些類型的運動比較好？



Our study relied on participants to report whether they had been physically active during the time between each check-in. Even though participants were provided training on how to think about the intensity levels, it’s possible that each participant had a slightly different perception of their activities.
這項研究依賴自我報告，而參與者對自己活動強度的看法可能有所不同。

For example, a participant may not have believed their recent walk actually qualified as a moderate-intensity activity. Physical activity monitors that can dissociate time and intensity might help future research unravel these associations more clearly. 比如把中等強度活動當作輕度活動。以後研究可用體徵監測儀。

It isn’t yet clear whether these short-term benefits accumulate over time to result in long-term improvements in brain health and dementia risk reduction. Research efforts are underway by our team to better understand these associations over broader timescales. 目前觀測到的運動對大腦健康的短期好處，尚不知對降低失智是否有長遠效果。Hakun教授的團隊正在研究。

My research involves data collection via smartphones and wearable devices to help us better understand how health-promoting behaviors and cognitive health interact as we age. This type of digital approach allows my team to pursue questions about how everyday behavior and experience influence cognition in daily life and represents a significant methodological advancement in the dementia risk and prevention research space.
用智能手機收集數據，了解促進老年健康的行為。

Using these tools, we aim to better identify individuals at risk for negative cognitive outcomes and new targets for dementia prevention. 識別失智風險，預防失智。