great prodict used with irunner logs all your activities from running, bike, gym sessions. i bought it as i have a heart condition and it records your heart rate even when i have an attack and max heart rate was 236!!! used it for 2 years and it keeps a log of all work outs calories burned etc when conected to iphone app. workouts also available to log max vo2 etc in app . top kit and batteries last ages.