Tara usually isn't the one to show off like this. But some experiments she did in her spare time let her to the discovery that allows her to convert air or water molecules into pure muscle mass. Wasting no time after this breaktrhrough she got to work on implementing the new technology into a simple looking valve. It may look unassuming but its stuffed full with her signature nanites that instantly fuse the plastic of it with the body of whover puts it on.
Of course Tara insisted oin testing it herself, and once she placed the valve over her belly button she firmly pressed down on it to initiate the nanites which quickly fused it with her skin. It felt rather nice to her, she would describe it as a warm tingling sensation. But as quickly as it started, it was over again. She let go of the valve between her fingers, and as expected it stayed put where it should. With a smile she gave her faint abs a good last look because they will be a lot bigger in no time.

After having changed into her sports clothes, Tara unwound the hose from the small portable air compressor. Opening the valve on her belly felt weird to say the least, she could feel herself tugging at it as if it were part of her body. But not to be deterred by the weird feeling she grabbed the end of the hose and shoved it inside the opening. It took her a few attempts because she had to fiddle with the nozzle to get it to stay inside. But once she managed to make it stay she flicked on the switch and the compressor sprung to life. Tara felt the air rushing inside her belly, it was a surreal feeling because her head expected her to inflate like a ballon, but isntead she was amazed at her abs which grew slowly but surely. As more and more air made its way into her she could feel all the muscles inside her body beginning to bulk up. Her previously tender biceps became big and defined, shoulders became wider and her legs became big meaty logs. Her poor little pants could barely contain the swelling mass inside them. Within a few minutes Tara went from small fit girl to big beefy body builder, and the huge grin on her face said it all. Once she was statisfied with her size she turned off the compressor and gave her new biceps a nice flex, all while admiring the newly added mass. Having finished admiring her new body she disconnected the hose and quickly closed the valve bevore all the air rushes out again.

"Now lest see what you can do"
She kissed both her biceps before grabbing the big set of dumbells she had prepared earlier.

---

A fun little idea i had and  Hitori_the_Artist did a great job with it.