輕度身體活動的健康價值被低估了嗎？

Are health benefits of light-intensity physical activity underestimated?

國際身體活動指引建議成年人每週應進行至少150分鐘的中強度有氧運動，或至少75分鐘高強度有氧運動，或以相等活動量進行中高強度組合活動。但這易讓人感到輕度身體活動（如：散步、遛狗、逛街購物、輕度家務勞動等）似乎沒有健康益處。近年逐漸有研究指出：輕度身體活動可為成年人（含老年人）帶來健康效益。本篇綜論檢視了以儀器測量輕度身體活動和其健康有關研究的重要議題，並討論輕度活動對18歲以上成年人的健康益處是否被低估。首先，描述國際間有關客觀測量輕度身體活動的現況。其次，分析以儀器測量身體活動相關研究的系統性文獻回顧及統合分析等證據，探討輕度身體活動與死亡率、罹病率及其他健康狀態之關係。最後，討論輕度身體活動的健康效益是否被低估的議題。整體而言，系統性文獻回顧及統合分析均支持輕度身體活動可提供成年人健康益處，且此效益獨立於中高強度身體活動的影響。部分研究建議成年人每天至少從事6小時的輕度身體活動以獲得健康效益，但須更多研究加以驗證。（台灣衛誌2021；40(1)：30-40）

International physical activity guidelines suggest that adults should engage in at least 150 min of moderate-intensity aerobic physical activity per week, at least 75 min of vigorous-intensity aerobic physical activity throughout the week, or an equivalent combination of moderate- and vigorous-intensity activity. This seems to imply that little or no health benefits can be reaped from light-intensity physical activity (LPA; e.g., walking slowly, shopping, walking a dog, lifting lightweight objects, and doing household chores). However, an increasing body of evidence indicates that LPA may provide health benefits for adults and older adults. This review examined several crucial aspects of LPA and health and assessed whether the health benefits of LPA for adults aged 18 or older are underestimated. The following procedures were implemented to review the evidence of device-based measurements of LPA and health. First, the country profiles of adults performing LPA were described. Second, evidence obtained through systematic reviews and meta-analyses was examined to explore how LPA relates to mortality, morbidity, and other health outcomes. Finally, research topics regarding whether the health benefits of LPA for adults are underestimated were evaluated. In summary, evidence from systematic reviews and meta-analyses based on device-based assessment of LPA supports the health benefits of LPA for adults, which are independent of the effects of moderate-to-vigorous-intensity physical activity. Although some studies have suggested that adults can achieve health benefits by engaging in LPA for at least 6 hours per day, further research is needed to confirm this finding. (Taiwan J Public Health. 2021;40(1):30-40)