RIYADH — The shops have not yet opened, but the air-conditioned concourse of a Riyadh shopping mall is crowded anyway — a haven for walkers and joggers grateful for somewhere cool to exercise.

The early-morning crowd includes 55-year-old engineer Mohammed Sultan, in a white T-shirt and black trainers, doing laps around the mall trailed by his niqab-wearing wife.

“It’s too hot outside to exercise. The weather here is cold and does not cause thirst,” Mr Sultan says, noting that even in October, the end of the hot period in Saudi Arabia, daytime temperatures can still approach 40°C.

“Walking in gyms (on a treadmill) is very boring,” he adds with a laugh.

It is a scene replicated daily in malls across the Saudi capital, highlighting how a growing interest in physical fitness in the Gulf kingdom has collided with a dearth of suitable spaces for working out.

Long popular in the United States, another car-centric country with an obesity problem, mall-walking is increasingly becoming a Saudi sport.

Roughly one in five Saudi adults is obese, according to an in-depth study published by the World Bank last year that described the issue as “alarming”.

To help bring that percentage down, the Saudi Sports for All Federation now organises races such as the Riyadh Marathon, which this year drew thousands of runners onto the capital’s streets.

But such events are fairly irregular, and new gyms sprouting up in Riyadh often charge steep fees — a turn-off for Saudis who spurn fancy machines and simply need space to stretch their legs.

Officials have begun work on a 135km Sports Boulevard in the capital featuring foot, cycle and horse-riding paths.