In this exploratory analysis of the AstraZeneca DETERMINE trials (Dapagliflozin Effect on Exercise Capacity Using a 6-Minute Walk Test in Patients With Heart Failure), we examined the effect of the SGLT2 (sodium-glucose transporter 2) inhibitor dapagliflozin on a range of accelerometer-based measures of physical activity in people with HF across the whole spectrum of left ventricular ejection fraction (LVEF).