隨著高齡者參與戶外活動的比例漸增，當今對於高齡遊客的研究與設計已成為熱門議題。在增進高齡遊客的使用者體驗方面，服務設計是常用的設計方法。然而，多數的服務設計流程是從使用者行為分析的角度執行，鮮少從生理負荷的層面著手；尤其從事戶外活動，若忽略遊客的生理負荷，可能會造成遊客體驗上的影響，對於生理機能退化的高齡者而言會更加顯著，因此服務設計流程應從更多元的觀點切入。本研究目的是從生理負荷的觀點，探索高齡遊客的需求，進而執行服務設計流程。透過監測受測者於戶外旅遊環境下的生理數據變化，並對照半結構式訪談和參與式觀察結果，分析高齡遊客活動時的生理狀態及行為模式，並以此需求完成服務設計流程。研究結果發現高齡遊客在活動時有「動態的體能變化」、「體能狀態變化的連續性」以及「個體之間不同程度的體能狀態變化」三個現象。本研究以這三個現象作為需求探索階段的成果，並提出評量旅客狀態和環境難度的模型，可協助預測遊客的狀態並提供適當的服務設計。

The proportion of elderly people who choose outdoor activities for leisure has increased and this has drawn attention from those who study elderly tourists and plan services for them. To enhance the user experience of elderly people during outdoor activities, service design that incorporates the concept of "user centricity" and "co-creativity" may be the best design solution. However, most methods for service design are based on behavior analysis; only a few use physiological load as a basis. Neglecting the level of physiological load during outdoor activities may affect user experiences, especially for elderly people, whose physical functions diminish with age. The purpose of this study is to demonstrate a service design process and execute demand searching from the aspect of physiological load. In this study, we embarked on the demand searching stage by observing physiological data of elderly tourists during outdoor activities. We then analyzed the results of physiological load using the results of semi-structured interviews and participant observation to ascertain demands from the aspect of physiological load, after which we proposed service design content. From the experiments, we discovered three phenomena – "dynamic status change", "effect of previous activities on stamina" and "variation in degree of status change under same environment" – that describe the stamina status of elderly individuals during outdoor activities. We then developed a model for evaluating tourists’ status and the difficulty of an environment that helps service designers craft appropriate services for elderly tourists.