Nairobi, July 18 -- Ask Wairimu Keriri about the fitness routine that has made her have an athletic physique of someone decades younger, and she won't name just one exercise.

Hockey. Swimming. Marathons. Triathlons. Boxing. Strength training. Calisthenics.

The director of the Nairobi Institute of Technology is a fitness junkie, and it has paid off.

"I turn 50 in five months," she says with a chuckle as she unpacks her gym bag at Hood Gym along Nairobi's Naivasha Road, an unassuming place that could easily be mistaken for a neighbourhood garage.

It may not be as sleek as many gyms in malls, but inside, the clang of metal plates and weights hitting the floor as fitness enthusiasts lift, push, and pull is a reminder that this is a place ...