A Lifestyle-based, PhysiCal AcTIVity IntErvention for Patients With Symptomatic Atrial Fibrillation (the ACTIVE-AF Study).

The physical activity intervention is designed to increase physical activity towards a weekly target of 210 minutes of moderate-intensity (Rating of Perceived Exertion <14 or <75% Heart rate reserve) physical activity. Vigorous activity (Rating of Perceived Exertion >14 or >75% Heart rate reserve), such as running may be used to substitute moderate activity at a ratio of 1:2 (i.e. 10 minutes of vigorous activity would equate to 20 minutes of moderate activity). This level of activity exceeds the American Heart Association Physical Activity guidelines (Haskell et al., 2007). The rationale for this intervention is based on the LOOK AHEAD study in which a target of 200 minutes per week was used, resulting in significant weight loss and improvements in cardiorespiratory fitness and traditional cardiovascular risk factors (Jakicic et al., 2009; Wing et al., 2013). The incremental benefit on health with a higher exercise dose is also supported by large epidemiological studies (Wen et al., 2012, Lancet). The program includes a weekly, 45-minute individual session (0-3 months) with an exercise physiologist (Dr Elliott), decreasing to fortnightly from 3-6 months. Within each session, participants will undertake supervised exercise training, discuss strategies to improve weekly PA and goal setting will be agreed between the health professional and the patient. Patients will maintain a journal detailing their physical activity and exercise habits. If required, additional sessions will be scheduled. 24-hour telephone and email support will be accessible to the patient. Participants will be asked to maintain a food diary and to adopt a diet consisting of high protein, low glycemic index foods.