The gym.

Samus wanted to know just what her new glutes were capable of. She walked down the corridor, jiggling all the way, until she found the perfect place to test them.

It was a gym. It was large, much larger than Samus would have thought it would be, filled with both simple weights of all sizes as well as some of the most advance workout machines she had ever laid eyes on. The walls were lined with mirrors, meaning she always had the opportunity to get a good look at herself. Her eyes wandered between all the equipment, picking out everything that could give her padded legs and butt a good workout.

As she entered the chamber, the AI took the time to speak up. "Might I provide a suggestion? If you plan to get some exercise in, then I recommend you pick up the upgrade on the console next to the door. It will configure your suit into a more appropriate and comfortable form for working out. You may also use the console to play any music you'd like, if you wish."

Samus looked around, and saw the console immediately to her side. Conveniently sticking out of it was an upgrade chip, just like the AI described. Samus picked it up and inserted it into her suit without hesitation. She yelped as she felt her suit suddenly snap into its new configuration.

After the surprise wore off, she jogged up to a mirror, quite aware of the clapping her cheeks made with each step. Checking herself out, she saw just what had changed. No longer was she wearing a full body suit. In fact, most of her skin was now exposed. Covering her breasts was a snug sports bra, still blue, keeping her tits under control but still allowing some cleavage to show. Covering her ample rear were some incredibly tight, blue spats. They formed an indent in her thighs and pushed each cheek up like a bra for her butt. She could also practically see her pussy under the fabric. The outfit reminded her of one of her own, something she would often wear in casual situations. She saw she had also been given some comfortable shoes as well as an orange sweatband on her forehead.

"Do I look good, or do I look good?" she said to herself, slowly turning to see how her curves were on display. She gave her hearty booty a firm smack, and watched as her cheeks jiggled and wobbled like gelatin, before slowly settling down.

Ready for a good workout, Samus walked back to the gym console. Flipping through the song selection, she picked out a playlist that she thought sounded perfectly appropriate: Booty Bops for Twerking Out.

As the beats began to play from speakers around the gym, Samus looked over the various exercise equipment available. "What do I use, first?" she wondered aloud.