隨著年紀增長，老年人罹患疾病的風險也跟著提高，尤其肌肉減少症(sarcopenia) 及較差 的功能性體適能被認為是衍生許多慢性疾病的開端。肌肉減少的問題會發生在40 歲之後，肌肉 質量每10 年大約減少8%，70 歲後更會增加至每10 年減少15%，並可能發生在體重穩定的老年 人身上。另一方面，老年人的綜合性問題，包含肌力與其功能的下降、內分泌的改變、活動量變 少和全身低度的發炎反應，會導致肌肉減少症，並進一步形成衰弱症候群(frailty syndrome)。因 此，老年人衰弱現象造成身體器官功能下降及骨骼肌肉的減少，容易促使身體遭受病毒或細菌的 感染及執行日常生活的功能性衰退，尤其會間接帶來骨質疏鬆症、營養不良等影響，以及增加跌 倒與骨折的風險，最終提高死亡率。結語：老化的過程所引起的肌肉減少是無可避免的現象，然 而，身體活動量的高低才是促使提升功能性體適能的表現，進而改善衰弱程度與死亡率的風險。

The prevalence of chronic diseases increases markedly with advancing age. In particular, the reasons for many chronic diseases in elderly are complex and include sarcopenia and low activity lead to poor functional fitness performance. The loss of muscle mass that occurs with after approximately 40 years of age, is accompanied by 8% per decade decline in muscle mass until 70 years old, as well as raise to 15 % after 70 years old and observed in stable-weight older people. In addition, frailty syndrome is a condition described in aging and characterized by decreased muscle strength and function, endocrine changes, lack of physical activities and chronic low-grade systemic inflammation. Therefore, frail older adults are a group increased risk of serious adverse clinical outcomes, including viral and bacterial infections, loss of independence, osteoporosis and increase risk for falls and fractures. Age-related loss of skeletal muscle mass and prevalence of chronic disease combined may lead to increased frailty, then raise risk for mortality. Regular physical activity increases exercise capacity and plays a role in both functional fitness performance and frailty prevention of mortality.