The smartwatch features sensors for stress management and a new ECG app.
The new model features built-in GPS and a new Active Zone Minutes feature.
The new model has updated sensors and up to 7 days of battery life.
The leader in fitness wearables takes aim at Apple.
The hugely popular activity tracker gets a sequel.
The company's newest activity tracker keeps its simple and stylish.
Fitbit challenges the Apple watch with a new fitness smartwatch.