The growing adoption of fitness wearables has resulted in the collection of extensive exercise and biometric data, with numerous studies highlighting the health benefits of such technologies. However, a persistent challenge remains: many commercial wearables lack long-term efficacy and motivational support, limiting sustained engagement and diminishing their overall impact on user health. This paper presents Synochi, an intelligent coaching system that integrates mainstream wearable devices with established sports science principles. The system aims to deliver adaptive training programs, personalised feedback, and sustained motivational support—addressing key limitations of existing wearables. Synochi features an adaptive training engine grounded in sports science literature and implemented using fuzzy logic and regression techniques to personalise and optimise training progression. A pilot qualitative user evaluation demonstrated positive user perceptions regarding both the system’s effectiveness and its ability to support motivation. These results suggest that the integration of sports science with wearable technologies offers significant potential to enhance long-term user engagement and maximise the health benefits of fitness wearables.