There's a heavy emphasis on Gym Battles in Pokémon Sword and Shield as trainers must be endorsed to qualify for the Galar region's Gym Challenge. Trainers must also wear a Gym Challenger Uniform while competing at each Gym.
Trainers earn a new uniform from each Gym Leader they defeat, and there's an option to buy more uniforms from a shop within most of the Gyms. After obtaining a new uniform, trainers eagerly head to the next Gym expecting a selection of uniforms to choose from. To many's dismay, trainers are led directly into the Gym's mission without the opportunity to switch out of their original Challenger Uniform.
Exhausting The Possibilities
Several methods of changing uniforms for the Gym Challenge came to mind, so I set to work exhausting the possibilities. It just didn't make sense trainers could earn new uniforms from every Gym Leader and buy them in shops with no real purpose of wearing them. But all attempts were made in vain.
Trying to manually access the Gym's changing room isn't possible and there's no difference between uniforms earned as rewards or bought from the store. None of them grant the option to switch up the uniform used in Gym Challenges.
Maybe there was a way to set the active uniform trainers would change into before entering each challenge? But scouring the uniform shop didn't reveal any such mechanic. Running all over the Gym lobby, clicking frantically to incite possible interactions yielded no results either.
In a desperate last attempt, I tried changing the trainer's outfit in the local boutique before entering the challenge. Though it gave townsfolk an eyeful seeing the trainer run through town in Nessa's water-type crop top and short shorts uniform, it was back to the old gym sweats once inside the challenge.
It's Just Not Possible
Many attempts have been made to change the Gym Challenger Uniform, but it seems it's just not possible. This is an odd choice in mechanics given that a new uniform is rewarded from every Gym Leader defeated. It's incredibly peculiar considering the advances to character customization in the game overall.
For many trainers who only care to wear these uniforms while competing in challenges, this missing feature means every uniform won from a Gym leader will just junk up the wardrobe. Though trainers who could care less about outfit coordination could find these to be a fun alternative to other clothing options. Being they're one-piece outfits, there's no matching required to rock one of these type-specific looks.
All in all, not being able to cycle through challenge uniforms isn't a huge deal, but it is rather unhygienic. Less fashion-conscious trainers may not even notice the lack of options in the changing room. However, a collection of trophy uniforms will only clutter the wardrobe and serve as a repetitive let down every time players scroll past them- especially if money was spent on store-bought uniforms.
Let's just hope the Gym League staff are keeping on top of the laundry.