AbstractAimsExergaming is a new tool to increase physical activity. This study aimed to determine the effects of access to a home‐based exergame (Nintendo Wii) in patients with heart failure (HF) on exercise capacity, self‐reported physical activity and patient‐reported outcome measures.Methods and resultsWe enrolled 605 HF patients in New York Heart Association functional class I–IV, independent of ejection fraction, in an international multicentre randomized controlled trial. Patients were randomized to exergame (intervention) or motivational support (control). The primary endpoint was change in submaximal aerobic exercise capacity as measured by the distance walked in 6 min (6MWT) between baseline and 3 months. Secondary endpoints included long‐term submaximal aerobic exercise capacity, muscle function, self‐reported physical activity, exercise motivation, exercise self‐efficacy at 3, 6 and 12 months. At baseline, patients on average walked 403 ± 142 m on the 6MWT. Patients in the exergame group walked further compared to controls at 3 months (454 ± 123 vs. 420 ± 127 m, P = 0.005), at 6 months (452 ± 123 vs. 426 ± 133 m, P = 0.015) and 12 months (456 ± 122 vs. 420 ± 135 m, P = 0.004). However, correcting for baseline 6MWT values by means of a linear mixed‐effects model revealed no main effect for the intervention on 6MWT. Small significant effects on muscle function were found. Statistically significant treatment effects were found for muscle function but after correction for baseline and confounders, only the treatment effect for the heel‐rise left at 6 months was significant (P < 0.05). No treatment effect was found for exercise motivation, exercise self‐efficacy, or self‐reported physical activity.ConclusionExergaming was safe and feasible in patients with HF with different profiles in different health care systems, cultures and climates. However, it was not effective in improving outcomes on submaximal aerobic exercise capacity. Subgroup analysis did not identify specific subgroups benefiting from the intervention.Clinical Trial Registration: ClinicalTrial.gov Identifier: NCT01785121.