Study aim: The purpose of the present study was to investigate the impact of a social media exercise platform (HeiaHeia, Helsinki, Finland) on the level of physical activity, physical fitness, wellbeing and body weight of the service users. Material and methods: The subject group consisted of 2862 individuals who voluntarily participated in a web survey. Their age, gender, body mass index, physical fitness level and activity information were self-reported. Results: Most of the service users (78.1%) exercised more than three times a week. About 75% of the users reported that they were in good or excellent physical fitness, while about 50% were overweight. More than half (64.6%) of the service users reported that they had perceived an increase in their level of physical activity; and 46.4% of them reported that they had perceived an advance in their physical fitness after using the social media service. In addition, 54.0% of the users perceived an increase in their wellbeing. Every fifth (21.3%) user reported a decreased body weight after using the service. Those users with lower levels of physical fitness, lower physical activity and who were overweight were more likely to report that the use of the present service was beneficial. In total, about 75% of the service users reported at least one benefit after using the service. Conclusion: The present study demonstrated that the use of the social media exercise service can lead to an enhanced perceived level of physical activity, fitness and wellbeing. It also impacts positively on the users’ body weight. Thus, the present social media service can be recommended for use, especially for overweight, unfit and sedentary customers.