There are lots of clever charging mechanisms for wearables. The ends of some straps turn into USB cables; others use clip-on charging docks that hook into the underside of your wearable; some actually have little micro USB sockets built in.
However, wireless charging is generally limited to fancier 'smartwatches' like the Moto 360 and Apple Watch. Pretty much all of them are based on the Qi standard (although Apple has locked you down to only using its proprietary docks... grrr), meaning you can use lots of third-party charging plates and not have to worry about cables anymore. Bliss.
We'd like to see this migrate down to smaller, more affordable trackers. Please.