Yes, you can upload workout data directly from a training device to iQO2.
iQO2 is compatible with more than 60+ devices including Garmin, SRM, CycleOps, Mio and Pioneer.

Garmin:

Devices using a USB cable to download files: Forerunner/Edge 10,110, 210, 220, 620, 500, 705, 800, 810, 1000, 920XT

Devices using Ant Agent to download files: Forerunner 50, 60, 70, 310XT, 405, 405CX, 410, 610, 910, 910XT, and Garmin Swim.

SRM:
Power Control 6,7,8

CycleOps:
Joule GPS, Joule, Joule 2.0, Joule 3.0

Pioneer:
Pioneer SGX-CA900, SCX-CA500

Mio:
Mio Cyclo 105 HC, Mio Cyclo 305 HC

Polar and Suunto products will not directly upload to iQO2. You can upload files from the manufacturer software.