This paper studied why middle-aged group is using active wear as casual wear. First, we can think of 'comfort', 'ideal body shape', 'trend', 'functionality', 'economy' for the reasons. We categorized the incentives as 'comfort/functionality pursuits', 'trend/economy pursuits', and 'ideal body shape pursuits'. Studies showed that statistically significant number of men pursue comfort and functionality, and statically significant number of women pursue trend and economy. Second, this study shows that the number of consumers who use the active wear in daily lives is greater than that of those who use it only for outdoor activities. The difference was statistically significant in T-shirts and pants. The most frequent usage was in social activities, and the next frequent usage was in cultural activities. The reason is that currently, middle-aged consumers are actively participating in social gatherings than any other activities. Especially, considering that the men wear active wear more than the women do, development of the product as men's casual wear that is compatible with other apparels will be necessary. We expect this study will be used as the preliminary data for a marketing strategy targeting the middle-ages.