China's marathon boom shows no sign of abating but, spurred by new government guidelines, the industry's focus is now on providing runners with an improved race-day experience.

Even with a spring chill and intermittent smog in the air, Beijing's dedicated army of runners pack the tracks and trails of Olympic Forest Park on weekends.

"It's been part of my weekend routine," said Hao Liang, a regular runner at the park, where a 10 km plastic runway encircles a lake, a legacy of the 2008 Olympics.

"If I missed the running exercise with my fellow club mates on Saturday, I would feel like I've missed the whole weekend.

"It's not just about staying fit, it's more important to hang out with same-minded guys to escape from your life pressure at least for a while. It's addictive," said Hao, who has completed 22 marathons and is a co-founder of Beijing-based Maker Run club.

Hao is typical of the health-conscious urbanites who have caught the running bug in major cities such as Beijing, Shanghai and Guangzhou.

According to the Chinese Athletics Association (CAA), nearly 5 million people took part in 1,102 registered running events in China last year, almost 20 times the 2014 number.

This Sunday, at least 40 races across the country will start at roughly the same time, indicating that the marathon calendar is becoming increasingly crowded.