It seams there is badly too little interest at this topic. Had hopes over time there will be some code (on the Marketplace for example), because it is over my skills to do this by my own. For Unity you find ANT+ Stuff, but not for UE4.
Bluetooth is great so far, but with ANT+ you get the actual Data faster.
Edit: Ok, I have googled a while and found this: Process In-Depth - DkIT Mahara
That looks promising.