Widget accessible while recording an activity?

According to this video (in German) it is possible to access widgets in watch mode by Long-pressing "menu". See Minute 8:06.

http://www.youtube.com/watch?v=O9nSZR_UyVo

But I do not know if it has some downsides on having to insert for example a map in a widget than as a data field oder app...

Those are simply data fields at the time you indicate, not widgets.

Right now, the watch and widget loop isn't accessible on devices while recording an activity. I don't know whether this will change in the future.

It would be extremely nice if widgets would be accessible during activities as this could give us a simple way o provide feedback in the activity - something that is not possible right now.
But given that data fields and widgets have very different permissions, this will probably not happen any time soon :-(

In the video at the time I cited above it is said (in German) that by longpressing the "menu" button you can acces the widgets (it is not shown in the viedo but it is said). Don't know maybe it is a wrong Information...