HOW HEART RATE HELPS MEASURE CALORIE BURN & HEART HEALTH
Your muscles need oxygen to burn calories and generate energy. Since exercise requires more energy, your heart beats faster to deliver more oxygen through the blood.
By measuring how fast your heart is beating, Fitbit trackers with PurePulse technology can more accurately gauge how many calories you’re burning.
As fitness improves, your heart becomes more efficient, and is able to pump more blood and oxygen to your muscles with every beat—which is why a decrease in resting heart rate suggests improved health.