Many would argue (including myself), that his previous look is much more aesthetically appealing.

Whilst no one would disagree that the effort required to build such a massive physique for a single role is astounding, at the end of the day, he probably won't choose to keep up his mass-building regime and stay the size he was in Thor.

Knight auditioned as an extra, and a half hour later he was part of the film.
While on set, he found himself doing what he does best - talking to other extras and actors about nutrition, diet and workout methods. He spoke with Red Dawn's lead actor, Chris Hemsworth, about the training needed to get him ready for his next role as Marvel Comics' Thor.

It wasn't long before Chris was a huge fan and became a key client.

The brilliance of Knight is, that he varies his workouts to the point where Chris wouldn't know what's coming next which keeps the interest levels high.

The key to Hemsworth's success is the fact he trained with more basic mediums.
Seldom working out with machines, Knight made him train with logs, kettle bells, ropes and other alternative methods which train the core (probably fit balls too)

Over a period of 6 months, Hemsworth trained with Knight, and also did plenty of on set lifting and carrying other cast members around which kept him in a constant state of 'pumped-and-swollen-goodness'