Bai Jinqin, 71, exercising at a gym in Tianjin. [Photo provided to China Daily]

When thinking of physical fitness, the image of a muscular young man in a gym may come to mind at first, rather than that of an elderly person with gray hair exercising on fitness equipment. However, fitness doesn't just belong to the younger generation in China. Seniors are also active in fashionable fitness routines, such as working out in gyms and running marathons.

Bai Jinqin, 71, from the northern port city of Tianjin, has been working out since 2005, when she began practicing yoga: "I had a severe sickness that year. After leaving the hospital I started doing physical training. Regaining my health made me realize how important and precious it is."

She now visits a gym six times a week, receiving professional training for an hour every session: "I've made big progress this year - my muscles are growing, my fat levels are falling and my cardio-pulmonary function is becoming stronger. As a result of being fit, I seldom catch cold and I maintain a good figure."

In the past five years, Feng Kaichen, from Hangzhou, Zhejiang province, has completed 25 full marathons and more than 10 half marathons.

"I had a chronic skin disorder for a long time, but running has strengthened my immunologic functions and the skin condition has cleared up. Even better, running keeps me from smoking and drinking," the 64-year-old said, adding that since taking up running he has lost 16 kg and his bulging stomach has flattened out.

The physical and psychological health of senior citizens is attracting considerable attention, especially as China's population is aging rapidly, according to a survey conducted on Oct 9 by the Office of the National Committee on Aging.

By the end of last year, the proportion of the population aged 60 or older had reached 16.15 percent, among which only 32.8 percent considered themselves to be in good physical condition.

However, as the fertility rate remains low and families get smaller, an increasing number of seniors are suffering from loneliness.

Bai believes it's important for seniors to meet new people when exercising to keep their minds young and healthy. "If the old always stay at home, they may become isolated from society and will feel lonelier. I enjoy communicating with young people - it makes me feel energetic and happy," she said.

The rapidly rising senior population is also providing a huge market for the anti-aging industry. Yang Yansui, a professor at Tsinghua University and an expert on social security, used the term "silver economy" to refer to the potential opportunities offered by China's aging population. According to a recent survey of seniors' living conditions in urban and rural areas, the per capita consumption of senior citizens has reached 14,764 yuan ($2,149) a year, resulting in total consumption reaching 3 trillion yuan annually, and older people are now spending more on cultural and leisure activities.

Bai spends 10,000 yuan on her fitness every year, and she considers it to be money well spent: "If you want a personal trainer, you pay 600 yuan for each session. That's three times the price of a group lesson, but the trainer instructs you one-to-one, points out your problems, helps you correct them and makes your training more efficient and effective."

Feng also spends a considerable amount of money on marathons every year, including entry fees and equipment costs. "You have to pay much more to enter a marathon abroad. If you don't qualify for free entry through your marathon times, the charity entry fee alone will cost you more than 10,000 yuan," he said, referring to the practice whereby those who complete marathons in China in a specified time gain cheaper entry to races overseas.

Although Feng wants to run a marathon abroad, he realizes that his speed will have to improve before that can happen.

The work of Liu Zhengzuo, general manager of Taizhou Vitality Fitness Equipment Marketing Co in Zhejiang province, revolves around the fitness of senior citizens. "Ten percent of our company's fitness equipment is designed for elderly people. In recent years sales have risen noticeably," he said.

Liu has long dreamed about opening a gym solely for seniors, but the high cost and other factors mean it has yet to become a reality: "At present, there are not many facilities for senior citizens, but I can see great market potential. Anyway, the physical condition of senior citizens is different from that of the young. The key to seniors' fitness is to do it step by step and achieve progress gradually," he said.

Chai Pingyan contributed to this story

Feng Kaichen, 64, with his finishing time after a marathon in Beijing. [Photo provided to China Daily]