Running, even for short distances, can be a lonely activity. Some people can cope, but others find it easier if they can find companionship.
Which accounts for the popularity perhaps, of a 'running companion service' set up in Shanghai.
But it's far from being a 'get rich quick' profession. These companions don't charge much, and most see it as a sideline to their regular jobs.
More important is the chance to share their passion for running and to offer some professional guidance at the same time.
In 2015, Chen Ming, was working for a foreign company in Shanghai, and set himself up as a running shop on an online platform, just for fun.
"There are many people who are not familiar with the idea of running, their choices of running equipment are limited, but I have a lot of ways to help them by offering the service," says Chen Ming.
He charges a one-off price of 200 yuan (USD 30) regardless of time or distance, but is open to negotiation.
Many people approached him for a consultation, but due to problems of finding the time and places to run, and trust issues, his business didn't thrive, and he was only able to make a maximum of two or three thousand yuan a month.
"I don't run with people to make money. That's not my purpose," says Chen.
Many people who provide such 'running companion' services have full time jobs, such as Han Tianhao, who does it in his spare time, while working in a family run company.
"How much I charge doesn't matter, I need to run anyway," Han Tianhao admits.
Jiang Xiaoxue, a second-year student, says she posted her running companion services online for about 3 months, but only 5 people came to her, "I only make pocket money by doing this."
As with all the 'Companions,' Han Tianhao's passion is running, and all he wants is to encourage those around him to exercise together.
"The key to running is mainly encouragement. Many people are lazy and feel bored when they run alone. When someone else is around, they feel secure and can carry on. In fact, I would love to be seen as a friend who runs along with them."
Jiang Xiaoxue, who offers a running companion service as a part-time job, says that after entering college, she moved less and less, so she had her own reason to take up exercise.
Jiang says you can look at the service as mutual supervision and companionship.
Chen Ming believes, "Running by oneself actually feels quite lonely. Men are sluggish by nature, and whether we go to the gym or play golf, we like to have a coach, because we want someone to accompany us. It's hard for a single person to persevere with something."
In addition to companionship, many runners need professional expertise. Chen Ming usually tailor-makes running programs for his customers, such as introducing them to the basics, or teaching correct running posture to more experienced runners, or advising on running equipment.
During the sessions, he determines the appropriate distance and speed, arranges a training plan and diet, as well as offering advice on injury prevention and treatment.
Some customers, he says, just want bespoke professional guidance that fits into their hectic schedules.
Similarly, Susan, who lives in Shanghai's Minhang district, teaches beginners 5 minutes of stretching before and after running.
During the run, she also adjusts their breathing and corrects their running posture.
The road to success is not always easy. Some running companions encounter trust issues.
One running client admitted, "In the beginning, I wasn't too sure, so I waited and observed Han Tianhao's running service for a long time. Eventually, after talking to him for a while, I felt he could be trusted. Plus, the place we agreed to run was on the University sports field, and I felt safe."
With the help of Han Tianhao, her wrong running posture was corrected and she developed the habit of regular exercise. "I'm very grateful to him."
Although Chen Ming sometimes gets calls from potential clients who don't trust his running companion service, he is not deterred, and waits patiently to establish the basic trust between him and his customers.
Senior running coach Wang Xiaogang said, "At the moment, such 'running companion' services are in their infancy. There is no industry standard to follow. It is only a private agreement between two parties, and such an agreement does not have a legal effect."
However, Wang Xiaogang is positive about the future of the industry. With the improvement of living standards, the public's health awareness is becoming stronger and stronger.
Wang says, "Any running companion service needs to provide professional advice and knowledge of optimizing posture, injury prevention, training plans, nutrition, weight loss, muscle strength training, and equipment."
He says that "there are nearly 1000 internationally certified running coaches, compared with less than 100, years ago."
The demand for running coaches in the domestic market is very large and is expected to rise at an alarming rate over the next few years.
Wang Xiaogang believes that, driven by the huge demand, the development of the industry is also very promising.
However, he warns that inevitably problems will emerge, such as disorderly competition, lack of unified management and a certification authority. Customers still need to be wary.