Since one third of our lives are spent in bed, it is hard to overlook the significance of sleep.

Tips to improve sleep, from traditional Chinese medicine (TCM) theories to clinical practices, can therefore benefit your life.

TCM practitioners believe that spring and the liver have the same property of "mu" (wood), thus the liver tends to be over-active, making people touchy.

The stomach and spleens have the "tu" (earth) property and is the opposite of "mu". If the opposition between these two properties becomes too strong, people will feel uncomfortable.

"Obviously, being angry and uncomfortable makes it hard to fall into sleep," says Dr Li Haicong, director of the Office of Geriatrics at the China-Japan Friendship Hospital in Beijing, who is also an experienced TCM practitioner.

The solution is to calm down the activity of the liver, and to reduce the burden on stomach and spleen, which can be fulfilled by a light diet and gentle exercise.

"Do not have too much strong-flavored food. Avoid intake of stimulating food or drink, such as pepper, alcohol and coffee," Li says.

Strongly recommended food includes fish, pork, duck, lily root, Chinese yam, asparagus lettuce, lotus seed, apples and bananas.

Chicken, mutton, beef and oranges are not advisable in spring.

"Aerobic exercises, such as jogging, playing badminton and swimming, are also beneficial to good sleep," Li adds.

Aerobic exercises will improve oxygen consumption and will prepare the body for peaceful sleep. But it should be done at least three hours before going to bed.

Taking a nap between 11 am to 1 pm, a traditional practice in China, is healthy, too, although many people have dropped the habit due to their faster-paced life.

"A nap should not be too long. About 15 to 30 minutes is enough," Li notes. "The quality of sleep is more important than the length."

For the elderly, who often have insomnia, perhaps due to chronic diseases, a good night's sleep is extremely important.

Li and his colleagues have found that a restful sleep will improve the condition of patients, which will in turn improve the sleep. And vice versa.

"If patients cannot sleep well, taking some TCM will be helpful, but that must be conducted under a doctors' guidance," Li says.