雖然已有許多研究指出身體活動對降低死亡風險的效果，但有關於閒暇時間身體活動的改變對全因死亡率之影響，仍有不同的爭論。因此本研究之主要目的在於分析不同閒暇時間身體活動的改變對全因死亡率之影響。本研究使用行政院衛生署國民健康局中年及老年人長期追蹤調查1996至2007年資料，以1996年50-89歲中年及老年男女計5,131人做為樣本基礎資料來源，並以1999年做為閒暇時間身體活動改變與否的分界點，分為閒暇時間身體活動不同的4組，且持續追蹤樣本存活情形至2007年止，將所有資料登錄並以Cox正比例涉險模式分析後發現：在閒暇時間身體活動改變上，由低提升為高身體活動量組及維持高身體活動量組之死亡風險皆顯著低於維持低身體活動量組，而由高減為低身體活動量組則並不顯著。綜合結果，本研究結論發現對於中年及老年人在閒暇時間身體活動改變上，由低提升為高身體活動量及維持高身體活動量顯著影響全因死亡率之差異。

It has been well documented that physical activity is associated with reduced risk of death. However, reports are still equivocal whether physical activity changes in later life is associated with mortality in older adults. This study aimed to examine the relationships of changes in leisure-time physical activity with mortality among middle-aged and older Taiwanese. The analyses were performed based on the national representative data from the Taiwan's Health and Living Status of the Elderly Survey conducted in 1996, 1999 and 2007. The data collected from the cohort of 5,131 participants, aged 50 years or above at baseline in 1996, and continued with 11 years of follow-up. Participants, engaging in at least three activity sessions per week were classified as being physically active. Based on the physical activity status in 1996 and 1999, activity status was classified into four categories (low/low, low/high, high/low and high/high). Cox's proportional hazards models were adopted to assess the associations between the changes in physical activity and all-cause mortality. Results indicated that the risk of death was significantly reduced in participants with increased and remained high physical activity levels compared to those with low physical activity levels. This study concludes that population engaging in regular physical activities in later life had lower risk of mortality.