Wherever he is - warming up a crowd of marathon runners in Tiananmen Square, or leading a pack of joggers in a Beijing park - Linus Holmsater is easy to spot.
A shock of blond hair, a pair of fluorescent pink shorts and a voice that bursts with enthusiasm are the unmistakable trademarks of the Swedish fitness instruction entrepreneur. He is a man on a mission to prevent China becoming a nation of computer-screen-watching fatties, intent on persuading people, by vigorous action and loquacious exhortation, that fitness can be fun, whether it is a gentle run around the local park or a mass aerobics session.
If Holmsater fails, it will not be for lack of effort or commitment. So far his mass exercise businesses, Heyrobics and HeyRunning, which are offered at cheap prices or even for free, are proving to be hugely popular, initially with the expatriate community in Beijing and, increasingly, with local Chinese.
Holmsater, 28, quit a well-paid job in finance to start Heyrobics, initially running it as a non-profit organisation seeking to get people off their couches. The long-term aim is to build a database of subscribers with commercial value, offer premium paid-for fitness programmes and tailor-make courses for corporations.
For now, though, Holmsater is focusing on increasing the number of participants and gaining wider exposure. Having tentative official blessing has helped - he led the Tiananmen Square warm-up for 30,000 participants in the Beijing marathon one year - along with appearing on local television. Regular HeyRunning sessions in the city's largest downtown park, Chaoyang, can attract a summertime crowd of up to a hundred people, while scores take part in the twice-weekly Heyrobics gym sessions involving work-outs with a strong social and networking element.
"I think the old people in China understand the importance of exercise and health but the young ones don't, unless they have been abroad," says Holmsater, whose father was the original founder of the Heyrobics exercise system. "I think exercise is super important, it will make you live longer and avoid illness.
"In China, people are not so interested in their health. They are more interested in showing off, buying nice products and having an expensive gym membership than actually going to the gym and using it.
"That is a big difference compared to Sweden, Britain and even Hong Kong, where people are looking at quality in a different way. It is coming to China - in just three years I have seen a big change - but they are still a few years off."
The boss practises what he preaches, running about 60 kilometres a week, plus spending hours exercising in the gym and on the odd game of football. He has a personal marathon best time of two hours, 31 minutes, which puts him squarely in the elite category of amateur athletes.
But keen runners such as him have limited opportunities to test their speed skills: for a major world city, Beijing has pitifully few races. Runners in Paris, New York, London or Hong Kong have a choice of road or trail, with competitions most weekends.
That is an issue Holmsater is trying to address by putting on regular five kilometre and 10 kilometre events - not officially classified as competitive races - in the city's splendid Olympic Forest Park, or downtown Chaoyang Park.
The downside to running outdoors is the dreadful pollution that can descend on the city for days or even weeks; keen runners always check with the United States embassy website, which measures the potentially lung-damaging fine particulates in the air and classifies the air from good (0-50) to hazardous (301 to 500).
Says Holmsater: "If it is over 300 we determine how it looks on the day; if it is over 200 we might reduce the intensity level; if it is higher, it is tougher on the heart.
"We connect our runners to the stores which supply masks that take out almost everything. But that is not ideal, I realise. I may wear a mask if I am in intensive training or else do a Heyrobics class instead."
Despite the risks, Beijing-based American doctor Richard Saint Cyr, a community health expert, says that venturing out for a jog on (relatively) clean air days is likely to do much more good than harm. But he does recommend being at least 100 metres from busy roads and, if there is even mild pollution, to consider wearing an N95 mask, a device originally designed to protect health workers from exposure to airborne diseases.
"The best research seems clear that the long-term benefits of exercise are still much greater than the long-term risks from pollution, traffic accidents and other concerns," he says. "Heart disease is still the world's top killer and exercise is crucial to protecting your heart."
Regular Heyrobics participant Lexie Morris, a Hong Kong-raised entrepreneur, ensures the pollution reading is below 300 before lacing up her running shoes. On a typical week, she spends a total of six hours at various HeyRunning sessions or Heyrobics classes.
Says Morris: "First and foremost it is so much fun! The first session I went along to absolutely killed me physically, and yet I smiled throughout the entire thing and had an awesome time."
Holmsater has hit the spot with his business, appealing, in particular, to young urban professionals. He also seems to have a way with officialdom, which is so vital for a successful business in China. But even he falls victim to mainland regulations. He recently finished high up in a race, but was disqualified because he was wearing the wrong colour shirt. "They do things by the book," he adds.