BEIJING, China - I hauled myself out of bed at 6 a.m. Sunday to set out for something I'd never done before–run a race in the Beijing marathon.

Jaime FlorCruz, far right, joins Zhang Lianqi, center, and another runner at the finish line.

I’ve been prepping for this day, on and off, for three months since I signed up to run 9.6K as part of the 2009 Beijing International Marathon, the full length of which is a little more than 42 kilometers.

My 58-year-old body seemed fit enough to run the distance, but I woke up with pinching pain on my left knee. For one brief moment, I thought that was a good reason to back out.

I decided to go and run. I had my muesli and banana, took a painkiller and proceeded to Tiananmen Square. Nearly 30,000 people, professionals and amateurs, had gathered there for the 29-year-old annual event. Foreigners paid $100 to register; Chinese paid 150 yuan ($22). Everyone gets a packet, including a runner's bag and bib, an official T-shirt and a certificate of participation.

At the starting line, some came in groups — high school and college students, factory workers, corporate employees, and members of runners’ club from various parts of China. Others came alone or with running buddies. Many joined to challenge themselves. Others, like the nine Chinese nuns from Henan province, run to support charity. Several runners wore distinctive T-shirts emblazoned with company logos ("Bimbo" Bread stands out) and uplifting message (the Obama slogan “Yes We Can” was eye-catching, if a bit tired).

I can too, I thought, as I jogged past Chairman Mao’s portrait soon after the start. Forty minutes and four kilometers later, however, my energy and enthusiasm started to flag. I puffed and winced, as I watched rabbit-like runners overtake me and deflated stragglers fall off behind me. Can I go on for five more Ks?

Just as I was losing confidence, I noticed an elderly man in red shirt, red shorts and blue sneakers, running just ahead of me. I sidled up and politely asked his age. "I’m 76,” he says, smiling.

Zhang Lianqi, it turns out, is a running aficionado. "I've been joining long-distance runs in Beijing since 1956," he recalls, keeping a slow but steady pace. “Once, I finished 37th.” He retired from his transistor-factory job 16 years ago but still jogs two to three kilometers three times a week.

That explains Zhang’s good form. "I've gained a bit of weight but I can still run," he quips. Along the way, he served as my mentor and inspiration. “Let’s not run in the middle of the street,” he suggests, so we avoid runners who are too fast or too slow. He took out two squares of chocolate from a yellow plastic bag and handed me one. “Don’t swallow, just let it melt in your mouth.” Soon, we passed 6K!

Impetuously, I picked up speed, inspired by periodic cheers ("Persistence means victory!") from onlookers and volunteers who’d lined the streets. “Pace yourself,” Zhang warned me. “Don’t run too fast.” Badly dehydrated, I fetched a bottle of water from a volunteer. “Don’t drink too much,” he says. “Just sip.” His most telling unsolicited advice involved attire. “Next time wear running shorts,” he admonished me. “Sweatpants drag you down.” Like a tour guide, he narrated a bit of history of Diaoyutai, as we ran past China's state guest house. He probably just wished to distract me. By the time he finished his spiel, we were only 600 meters away from our goal.

Literally shoulder to shoulder, we crossed the 9.6K finish line. As we posed for souvenir pictures and exchanged phone numbers, I felt especially exhilarated to have found in Mr. Zhang a running companion, a mentor and another Beijing friend. I am glad he pushed me to the finish line.