The Effect of Exercise Prescription and Delivery in Congenital Heart Disease – The Congenital Heart Fitness Intervention Trial: CH-FIT

Eligible participants will be randomised to either a supervised (or partially) physical activity and exercise program of moderate to vigorous intensity, followed by an 8-month maintenance period; or usual care (control) group. Throughout the intervention period, participants in the intervention groups will also receive education to promote a healthy lifestyle. In the intervention groups, a 5-10 minute warm-up and cool down will be performed before and after each session. Adherence will be monitored by recording session attendance. Sessions in the 4-month supervised (or partially supervised) phase will be delivered by exercise professionals (e.g., exercise physiologists, physiotherapists) in small groups. Adolescents and adults with biventricular congenital heart disease will be randomly allocated to a telehealth exercise training group or usual care group; Fontan participants may also be allocated to a traditional exercise training group. Children will be randomly allocated to a physical activity and exercise training group or usual care group. The exercise intervention in the traditional exercise group will involve supervised aerobic (e.g., cycling) and resistance exercise (e.g., leg press, chest press) training 3 times a week for 4 months. Sessions will be ~60-75 minutes and supervised by exercise professionals. Aerobic exercise will commence at 40%-50% of heart rate reserve (HRR) and progress to 70%-80% HRR, as tolerated. The resistance exercise component will involve 3 sets of 8-12 repetitions at 60% of one-repetition maximum (1RM) and progressed to 70% 1RM. The telehealth exercise training group will perform supervised resistance exercise 3 times a week for 4-months on Zoom. Each supervised resistance training session will be ~45-60 minutes in duration. Participants will perform 3 sets of 8-12 repetitions of various exercises using bodyweight or a Gymstick. Resistance exercise intensity and progression will be monitored by rating of perceived exertion on the OMNI scale. Participants in the telehealth exercise training group will also be asked to perform 20 minutes of aerobic exercise training (e.g., walking) independently 3 times a week for 4-months. Aerobic exercise intensity will be monitored by HRR and is consistent with the traditional exercise training group. Children allocated to the intervention group will participate in a 4-month supervised physical activity and exercise training program. Participants will attend a community or fitness facility once a week for ~90 minutes to perform an interval exercise circuit, practice foundational movement skills and engage in physically active games. The average target exercise intensity for the exercise circuit will be 40%-50% HRR initially and will progress to 70%-80% HRR, as tolerated. In addition, children will be provided with tasks to complete at home (e.g., calf raises) that supplements the physical activity program and promotes a healthy lifestyle. During the 8-month maintenance phase, adolescent and adult participants allocated in the exercise intervention groups will be encouraged to continue exercise training independently at least 2 times a week. Children will be encouraged to be physically active and join sports clubs. Follow-up phone calls will be conducted monthly to facilitate ongoing physical activity participation. Participants in the usual care group will continue with routine clinical care and attend testing visits at baseline, 4-months, and 12-months.