Meet the Mio VELO: a wristband that enables cyclists to monitor their heart rate as they exercise. There is no need to rely on a chest strap to read accurate heart rate data when you have one of these wearables. The device transmits data from ANT+ speed and cadence sensors directly to smartphone apps. You get 5 configurable heart zones to customize your workouts.
The Mio VELO has LED that flashes to show your current heart rate zone. You can use various fitness apps to put this wearable to good use. The battery life is good for up to 8 hours. The Mio VELO is water resistant. You can get it for under $130.