These wrist bands are all the rage for helping you stay fit. Overall demand for such personal devices is growing so fast that the industry is expected to be worth 34 billion US dollars by 2020. 

Wearable technology departments in many stores are packed with products as popularity increases for smartwatches and fitness and health trackers. Wearables will be the top fitness trend for a second straight year in 2017. That's according to the American College of Sports Medicine. 

Wearable technology includes activity trackers, smart watches, heart monitors and GPS tracking devices. People now enjoy gathering their own health data to make lifestyle choices, and the most successful wearables today are those for the wrist.