Get fit faster with MIO Alpha - The MIO Alpha is the world"s first sport watch to provide continuous, accurate heart rate monitoring at performance levels - without requiring a chest strap. This heart rate monitor uses optical sensors to measure the blood flow through capillaries in the wrist to determine heart rate. This stylish watch sits comfortable on the wrist - it"s not too big or heavy - and is stylish enough to be worn when not training as well. Training with a heart rate monitor sport watch helps attain specific fitness goals more effectively. Whether focused on fat-burning, aerobic conditioning, endurance, speed or general fitness - heart rate training is one of the most effective techniques that can be used. Alpha talks Bluetooth® Smart (4.0), so with a supported device, like an iPhone, you can connect wirelessly and keep a record of your heart rate during the entire length of your activities. This record can be analyzed to further improve the effectiveness of your fitness training.Customizable heart rate zones to suit your training prescription.Data review (total exercise time, average heart rate, time "in zone").Tested accurate at performance speeds.