ZigBee sounds a bit strange but Bluetooth is not better, right? However, the promotors of ZigBee tell us that it is not competitive to Bluetooth cause of it's specifications. And there are some interesting advantages for wearable applications namely in the industry sector:

ZigBee is the only wireless standards-based technology:

• that addresses the unique needs of remote monitoring & control, and sensory network applications.
• enables broad-based deployment of wireless networks with low cost, low power solutions.
• provides the ability to run for years on inexpensive primary batteries for a typical monitoring application.

It's initial marktes are home-, building- and industrial automation. Some products are already available.