Hands-on with TomTom's new Spark GPS running watch (pictures)

The TomTom Spark is a line of six running watches, all of which include GPS, all-day activity tracking (steps, distance, calories burned, active minutes), automatic sleep tracking, Bluetooth to connect with smartphones, interval training and a water-resistant rating of 5 ATM.

The entry-level TomTom Spark only includes the features listed above. The TomTom Spark Cardio adds a built-in optical heart rate sensor. The TomTom Spark Music doesn't include a heart rate sensor, but does include 3GB of storage for songs. If you want both heart rate tracking and music storage, there's the TomTom Spark Cardio + Music.

TomTom is also offering two additional models of the TomTom Spark Music and the TomTom Spark Cardio + Music that will come bundled with a pair of TomTom-branded Bluetooth headphones.

This is the TomTom Spark Cardio + Music. It features an optical heart-rate sensor on the back and has 3GB of space to store up to 500 songs right on your wrist.

It's looks similar to TomTom's current running watch, the TomTom Runner Cardio.

The watch can sync wirelessly with Android and iOS devices. You can also pair a Bluetooth heart-rate strap to the entry-level model, which doesn't include the built-in optical sensor.

TomTom said that an update slated to arrive by the end of 2015 will also add smartphone notifications and continuous heart rate tracking.

The TomTom Spark Cardio + Music is available now for preorder in the UK for £190. Preorders will start on October 1 in the US for $249. The full range of Spark watches will be available for purchase on October 15.