Background: Physical activity is often described as being important for people of all ages, but what different people mean when they talk about physical activity is unclear. Method: A phenomenographic method was used to analyze how 13 older people and 17 professionals answer the question, “If I say physical activity, what does the concept mean to you?” as part of semi-structured interviews conducted in four assisted living facilities in two different municipalities. Results: We identified a number of different perceptions of physical activity, with the older people and professionals having different responses. Elderly and professionals alike, define physical activity as a requirement for life and as an opportunity to maintain the body although they define the concepts in different ways. Elderly define the concept as a way to create meaning and the professionals have the attitude that the concept means everyday activities. Conclusion: The concept of physical activity may be defined in many different ways. This study has shown that elderly and professionals do not define physical activity in the same way. Therefore, professionals need to be aware of these differences when talking with elderly about individual needs in everyday life.