Thor was a big turning point for Marvel Studios, as they went from focusing on an Armoured Avenger to a God of Thunder. The hero's origin story was effectively told, and while he was decked out in regular clothes on Earth thanks to Odin stripping him of his powers, Thor remained in his Asgardian costume (sometimes without the cape) while on Asgard.
Now, though, Marvel Studios Head of Visual Development Charlie Wen has shared another early design for Thor's costumes which was created before Chris Hemsworth boarded the project.
Designed as a "training outfit" for the character, Wen explains that, "We spend much of our lives 'in training.' We’re always getting better at something. Hopefully, it’s getting better at something we are striving for, or getting better at being the kind of person we want to be. That was Thor’s journey too. He had to learn to live for something beyond himself in order to be ready to be a leader to Asgard."
It definitely would have been interesting to see Thor "in training," but it's clearly a sequence which ended up on the cutting room floor as the movie continued to be developed over the years.
Check out the concept art below: