Katie kept walking, pushing through her tween years. She got taller and thinner as the last of her baby fat drained out. As she finally hit her teen years at 13, she felt a tingle in her chest. She looked down to see that her nipples were making slight indentations in her tank top. As she walked, her nipples rubbed against her tank top more, feeling more sensitive as they did. The areas around them started getting more puffy as tissue began forming. "I'm growing boobies," said Katie, her mind expanding to explain what puberty is. The discomfort faded as a training bra appeared under her tank top, comfortably cradling her nascent breasts.
The beginning of puberty spurred Katie to walk even more, wondering how big she was going to get. As she continued through her teen years, she gained more height. Her legs became more shapely as her thighs and hips start filling out. She could feel her butt growing into a more appealing shape. Her tank top pulled up more, showing her belly button. Her training bra became a proper bra as her breasts expanded, putting her into the upper B's. Katie's face got prettier as her lips became fuller and her face started losing its roundness. Her hair grew longer before a band put it into a ponytail. At 16, Katie was becoming a looker and she knew it. "Sweet sixteen and ready to drive," she said proudly, her voice not sounding as high-pitched as before.
16 looked good, but there wasn't quite enough freedom for Katie. She pushed onward, going through the last of her high school years. She gained a little more height as her legs grew even more shapely. She could feel her hips and rear growing out to a childbearing form and a tingle through her groin told her she was fully ready to have children of her own. Her tank top fully slid up to reveal her flat stomach as it merged with her bra to become a sports bra. Her breasts swelled up to C cups as her cleavage became more displayed. Lipstick and earrings appeared as she pushed past what would have been her high school graduation. "I'm a legal adult," said Katie proudly, her voice dropping into a lovely tenor. At 18, she was now free to pursue adult interests.
18 may be the age where adult access is unlocked, but 21 is where the fun really starts. Katie pushed herself to reach that. Puberty had a last few gifts to give to her before it finished. Another two inches of height finished her growth. Her butt, no, her ass was now a perfect peach that any guy would look at. Though plenty of them would also be watching her tits especially as they swelled into the D class. Wilder thoughts entered Katie's mind as new possibilities open. "I'm going to party hard tonight," said the 21-year-old college girl.
Though Katie was a fully grown woman with a sexy figure, something intrigued her. After all her walking, her muscles weren't nearly as big as she expected them to be. She was hardly out of shape, but she would have thought all her walking would be reflected more. "Let's see if I can work on that," she said as she kept walking. As she walked, she gained more memories of fitness courses and knowledge about physical regiments. The changes soon became noticeable. Her shapely legs grew more toned as the years of walking became physically present. Her arms also thickened as years of workouts were added on. Her exposed midriff rippled before her abs pushed out, becoming more defined until a hard six-pack was formed. Katie felt a rush of power as she became a female bodybuilder at 25.
A small nagging thought came to Katie's attention. Her mom was bound to be waiting for her after she finished in the arcade. Of course, Katie was now way too old to possibly be her daughter. More likely, she'll be her sister, her younger sister. The thought rankled Katie a little over her former mother holding seniority over her. Maybe just a little more to meet her mother's age. A few more years meant more muscles being built. Her legs thickened even more, yet she retained enough to keep them from looking grotesque. Her arms grew even more bigger, a very considerable amount of strength being added. Her abs didn't look just sculpted, they looked carved. She had been able to build up a legendary 8-pack to the envy of both men and women. At 30, no one was going to be pushing Katie around. "Wait until 'Mom' sees her twin," she said smugly.
And yet being the same age of her former mother wasn't enough. Katie wanted to be superior. She wanted to be the older sister. Just a few more minutes. Her already Herculean body didn't change much as it was already at the peak of physical power. However, her skin darkened as she developed a deep tan. Of course, that was from all the bodybuilding competitions she's been to, most often at the beach. She also did some modeling work as she still had a womanly figure with D cups. When Katie hit 33, she finally hit the stop button and the treadmill leveled out. Katie looked down at the bronze goddess she had become. "Damn, I really grew up," she said as she felt her tight core. She wondered if she pushed herself too far. She was almost 5 times older than she was earlier.