Watches

Wearing a smartwatch during sporting activities, can help to monitor your body and provide feedback to improve performance, etc.  Garmin is a premier manufacturer of sports and fitness watches/trackers, their watches can monitor your heart rate, SpO2, VoMax; as well as counting steps, calories burnt, etc.

They can even provide you with a fitness plan to follow, so it's like having a personal trainer on your wrist; with the ability to sync all the data to your mobile device and the cloud.