We designed an English as a foreign language (EFL) learning activity supported by smart watches to combine EFL learning with physical exercise such as walking around the school community. We tested the feasibility of our approach to facilitate EFL learning and make it healthy and enjoyable through single subject experimental design. In addition, we researched the affordances of smart watches for EFL learning and healthy and enjoyable living. We collected the following data: (1) student learning outcomes evaluations, (2) a questionnaire survey, and (3) interviews with the students. According to our results, the students performed the best on learning tasks when they used smart watches. The students perceived that smart watches were easy to use and useful for EFL learning. They also perceived that the learning activity supported by smart watches was useful for their health and positive emotions. The students mentioned several features of smart watches that were useful for EFL learning, physical activity, and positive emotions. For example, the dictionary in smart watches helped the students translate unfamiliar vocabulary, and the fitness tracking tool helped track and record the number of steps taken. The students were happy to learn EFL and to monitor their physical activity progress using smart watches. Furthermore, a significant correlation between learning performance and physical activity was revealed, suggesting that the students who did more physical exercise are those who demonstrate better learning performance. On the other hand, no correlation between learning performance and student perceptions and between physical activity and student perceptions was found, suggesting that most students, no matter how well they performed and exercised, had positive perceptions. Based on our results, we suggest designing learning activities combined with physical exercise supported by smart watches to facilitate EFL learning, physical activity, and positive emotions.