While people try various products and services to help them get better sleep, they most likely ignore a key remedy - their biological clocks.

A recent survey shows that online shopping, chatting on social media and enjoying videos form the most popular pre-bedtime entertainment, on which people spend an average of 65 minutes daily.

"These activities cause longtime excitement of the cranial nerves, and in turn cause sleep difficulties," says Gao Xuemei, the vice-chairman of the Chinese Sleep Research Society, which released the survey.

The survey, released at a news conference on March 17, was jointly conducted by the society and De Rucci, a Chinese corporation dedicated to improving lifestyles and sleep, and was based on big data from more than 515 million Chinese internet users collected over a period of two years.

Speaking about the survey's findings, Gao says that between 10 pm and 11 pm, which is supposed to be an ideal time to go to bed, is both the peak hour for online shopping and watching short videos.

Chen Yannan, who recently graduated from university, habitually chats with friends or watches videos for an hour or so before sleeping.

"Often, before I am aware, it is already late. And sometimes I get so excited that I cannot sleep well," says the 22-year-old from Quanzhou, in Fujian province.

Chen adds that she now finds it difficult to change her habits. "Sometimes, even though I force myself to go to bed early, I cannot fall asleep until it is 2 or 3 am," she says.

Chen also says that she expects the situation to get worse as she plans to look for a job. And she admits that she's kind of anxious and lost, and believes that this has also affected her sleep.

Speaking about the problems she faces, Chen says that she suffered from insomnia for about one month, and it had obvious health consequences, including an inability to focus during the day.

Meanwhile, the survey shows that more than 80 percent of those surveyed pay attention to their sleep quality, and pressure at work remains the major factor affecting it.

More than half of those surveyed say they sacrificed sleep hours to complete work assignments.

The survey also showed that those in "high-tension" sectors such as finance, suffered from more sleep problems.

Gao's society - founded in 1994 by the China Association for Science and Technology - also says the China theme for World Sleep Day (March 21) is "Keep Good Hours, Get Healthy Sleep".