BEIJING, March 21 (Xinhua) -- On the World Sleep Day on Thursday, Chinese experts reminded people to improve their quality of sleep amid concerns over unhealthy sleeping habits.

A recent survey conducted by the China Sleep Research Society (CSRS) revealed that only 29 percent of respondents reported habitually going to bed before 11 p.m., while 47 percent usually fall asleep after midnight.

The survey also showed that college students tend to spend a significant amount of time on their mobile phones daily and have a tendency to stay up very late.

Lu Lin, president of the Peking University Sixth Hospital and member of the Chinese Academy of Sciences, cautioned that unhealthy sleeping habits could increase the risks of developing cardiovascular, cerebrovascular, endocrine and many other chronic diseases.

It's not just about the duration of sleep, but the quality, depth and continuity of sleep are also crucial factors to consider, said Ou Qiong, an expert with the CSRS. "Sound sleep helps improve the immune functions of our body."

The experts have advised people to reduce their consumption of caffeine and cigarettes before bedtime, maintain a regular schedule for work and rest, engage in regular exercise, and refrain from using electronic devices before sleep.

They also recommended incorporating meditation and yoga into daily routines to alleviate stress.