Mobile Health Technology

Tailored text messages are initially sent daily, then reduced to weekly frequency after 4 weeks. During workouts, the watch provides visual and haptic alerts indicating whether the participant is in the correct heart-rate zone. Message selection follows a decision tree based on watch-recorded adherence, including completed sessions, session duration, and time in the prescribed heart-rate zone. The exercise specialist uses post-session feedback, daily physical activity data, and exercising heart-rate data to modify and progress the programme. The MOTAFIT intervention uses three linked tools: Polar Flow for Coach for the exercise specialist, the Polar Flow smartphone app for participants, and the Polar Ignite 2 fitness watch.