Understanding and Improving your Sleep

By Greg Wells PhD and Fiona Callender

Ultra Runner Ray Zahab catching a few Z's during the Andes Run expedition (www.andesrun.com)Sleep is an imperative part of any person’s life; we can’t live without it. hormones have powerful effects on the human body. But did you know they are responsible for that drowsy feeling you get
in the evening? A hormone called melatonin is closely involved in the sleep process. It is secreted from the pineal gland, a tiny organ in the middle of your brain right behind the eyes. The production of melatonin is increased 50-fold at night. Levels of melatonin released from the brain increase during the course of the evening, peak during the night and then decrease during the day. Production during the day is decreased because the pineal gland is sensitive to bright light. There are direct nerve connections from the optic nerve to the pineal gland. This is why it is so important to keep your room dark at night, and why, if possible, you should avoid turning on lights during the night—for instance, when you’re going to the bathroom at 2 a.m. The light stimulus can turn off melatonin production and disrupt the quality of your sleep.

Sleep isn’t a reduction in neural activity; it is a change in neural activity. A widely accepted idea is that sleep allows the brain to restore biochemical or physiological processes that progressively degraded in wakefulness. Many hormonal processes take place while you are sleeping. The majority of growth hormone (GH) release occurs during sleep. Growth hormone is responsible for increasing glucose uptake in muscle, enhancing protein synthesis in the liver and muscle, and causing the breakdown of fat. Growth hormone also strengthens and increases mineralization of bone, increases skeletal muscle mass, reduces liver uptake of glucose, promotes glucose formation by liver, stimulates the immune system and contributes to the maintenance and function of the pancreatic islets. Simply put – when we sleep growth hormone is released, and growth hormone helps your body repair and heal itself.

Leptin secretion and regulation is also highly dependent on sleep duration. Leptin is a hormone released by fat cells that signals the feeling of “fullness” to the brain and therefore suppresses appetite. Low leptin levels make a person feel hungry even when they are full, leading to overeating and weight gain. This is how getting a good sleep can help people control their weight – if you get a good night sleep you won’t be as hungry during the day.

Here are some tips for getting a better night sleep:

Allow your body some down time before falling asleep. Prepare for bed 30 minutes before you plan to fall asleep and do something relaxing like reading a book.

Try to go to sleep and wake up at the same time everyday so that you get yourself in a good, constant sleep-wake rhythm. Having a consistent wake-up time will also help create a consistent sleeping pattern that will improve the quality of your sleep.

Avoid electronics right before bed and in the bedroom when you are trying to sleep. Screens on things like cell phones and televisions produce a constant high speed flashing of light and make it difficult to sleep. This artificial light reduces the production of the hormone melatonin, which as we discussed, promotes sleep.

Write down your to-do list for the next day so you don’t have to think about it as you are trying to fall asleep. Concentration or strong emotions, such as anxiety, can a keep you aroused and therefore awake. It is much easier to stay awake when you are sleepy than to fall asleep when you are wide-awake. Keep a note pad beside your bed to write things down so that you won’t forget them but you can not worry about them while you’re getting ready to sleep or if you wake up at night with an active mind.

Avoid caffeine for at least 6 hours before sleep (try not to have it after lunchtime). Caffeine blocks adenosine receptors in the brain, blocking adenosine’s inhibitory actions on your brain’s arousal centers. Adenosine concentrations rise the longer you are awake and help you fall asleep – but caffeine blocks their effects.

Have a small snack containing a small amount of protein with some carbohydrate. A good idea is some cereal and milk. Milk contains the amino acid tryptophan, which is used in the brain to make serotonin. Serotonin is a neurotransmitter that causes you to become sleepy. Eating carbs along with tryptophan containing foods raises insulin levels and makes it easier for the tryptophan to enter the brain.

Greg Wells PhD is an Assistant Professor in the Faculty of Kinesiology at the University of Toronto where he directs the Human Physiology Research Unit. He is also the author of Superbodies: Peak Performance Secrets from the Worlds Best Athletes. Fiona Callender is a nationally ranked track and field athlete who is currently studying Kinesiology at the University of Toronto.