RecruitingBehavioural interventionMOVE-HF MOtivating Physical Activity With BehaVioral Economics in Heart Failure With Preserved Ejection FractionThis is a three-arm, randomized, controlled trial to test the effectiveness of gamification plus a social incentive - either social support or competition - to increase adherence to physical activity among individuals with HFpEF. There will be a 2-week run-in period to obtain baseline measures of physical activity, followed by a 6-month intervention period and then a 3-month follow-up period.