Nairobi, July 11 -- Most people walk into a gym hoping to lose weight. Keziah Wambui walked in hoping for nothing at all. In fact, the gym was never part of the plan.

"I was such a tiny girl that exercise had never even crossed my mind. It wasn't something I imagined myself doing," she says.

When you look at Keziah, the first impression is that of a woman who has already achieved every fitness goal.

The 30-year-old spends most of her days behind her laptop, writing code, fixing malfunctioning software, and building systems.

After work, she transforms into a dedicated athlete whose lower body, chiselled core and defined arms bear the unmistakable stamp of years of heavy lifting and punishing CrossFit workouts.

"That's what happens whe...