By Xinhua photographer and writer Qin Lang

NEW YORK, Nov. 4 (Xinhua) -- The just-concluded New York Marathon saw some 224 Chinese participants fly across the globe to take part in the prestigious event. With interest in marathon among Chinese athletes (both professional and amateur alike) at an all-time high, it is a good time to take stock of what is causing this surge in interest in the sport.

The rapid expansion of marathon running among the Chinese public is a surprising phenomenon for many observers. The country, although boasting a robust and varied mass-sports and public fitness tradition, has lacked a running culture for most of its modern history.

So what explains the growth of marathon in this country of 1.4 billion people? The answer can be broken down to three factors.

Firstly, an economically-developing country like China must, out of necessity, find new and innovative ways to promote healthy-lifestyles among an emerging middle-class who likely spend much of their day sitting at desks in white-collar offices. To this end, both the public and private sector in China have taken steps to spur interest in marathon running.

Public sector efforts to this end are mainly being waged by local governments, who are eager to promote fitness among the general public and to take advantage of the significant tourism and economic development boost that hosting even low-level marathons can bring to a locale.

Private-sector efforts have been spearheaded by Chinese conglomerate Wanda Group, who last year inked a partnership with the Abbot World Marathon Majors that will eventually see a major world marathon come to a first-tier Chinese city.

This is an understandable development, but its importance cannot be overstated. Chinese companies are increasingly aware of the huge commercial potential for marathon-running in a country that is taking ever-more strident efforts to promote public fitness.

Sponsorship opportunities in the next several years will be rife, and companies are eager to position themselves well in order to capitalize on them.

The reason that commercial and marketing opportunities will be so widespread is closely linked with the second major factor behind the growth of marathon running in China: marathon is a mass, egalitarian sport with very few barriers to entry.

Anyone willing to go the distance can stand at the starting line with the giants of the sport, and sheer determination and grit can help one perform well or even come out on top.

Unlike many other sports that have significant hurdles that need to be cleared in order to participate at the highest-levels, marathon requires only a willingness and drive to train oneself mentally and physically to compete. Anyone with a place to run and the mettle to work hard can make it happen.

Finally, marathon running provides an easy way for China's best professional and amateur athletes to gain valuable international experience running in a wide variety of conditions and locales.

The London marathon, for example, saw a record-number of Chinese participants this year, and figures are bearing out similarly for a number of top international marathons around the globe. With runners, businesses, and the public sector in China all showing that they are ready to go the distance, it is clear that interest in marathon running is only going to increase exponentially in the future.