Abstract：The overall demographic trend in Taiwan has seen a dramatic increase in the proportion of citizens who are elderly, and accompanying physical and mental health problems have increased economic stress on families and society as a whole. To achieve the goal of ＂successful aging＂ in life, we should focus on ＂front-end＂ precautionary measures that assist the elderly in maintaining good physical and mental health. This so-called ＂solving the problem at root＂ scheme helps us avoid the pressure of the current ＂back-end＂ medical healthcare measures. This article reviews the relevant literature to investigate the essence of therapeutic recreation. Its goal is to provide a reference for practice and academic research in the field of therapeutic recreation by outlining the implications of implementing principles of physical activity for the elderly. First, it discusses the essence of physical activity in therapeutic recreation for the elderly, leading into its core values and implications. Then it develops appropriate guidelines of physical activity in therapeutic recreation for the elderly based on the developed theory. We conclude that therapeutic recreation emphasizes ＂recreation.＂ Notable features include enjoyment, multisensory stimulation, unstable arrangements, and group interaction. Design principles for physical activities include intensity, type, experience, safety, freedom of choice, and alternatives among actions or movements. These comprehensive principles and practices for health-enhancement of the elderly through physical activity in therapeutic recreation may aid in eliminating the financial pressures and solving the aging problem for families, the society and the country. (Full text)