Catching more Zs can help you be healthy

By MJ Stevens

Monday, July 13, 2015 | 2 a.m.

Too little, and you feel like a zombie. Too much, and you end up groggy. Most people know a regular sleep schedule is important, but many fail to make it a priority. With busy calendars, distracting technology and energy drinks that can keep us awake for hours, sleep quickly can fall to the wayside. But it’s vital to a person’s overall health and well-being.

Sleep makes people more alert, more energetic, happier and better able to function. Scientists found that after 17 to 19 hours without sleep, people performed on tests as if they had a blood-alcohol content of 0.05 percent. After 20 hours, the level increased to 0.1 percent. Response speeds were up to 50 percent slower and accuracy levels were poor.

A lack of sleep has been linked to heart disease, diabetes and obesity. On the other hand, sufficient sleep can improve your sex life, lower your risk of injury, aid in pain relief and improve memory and cognition.

How to sleep better

1. Stick to a sleep schedule, even on weekends. Go to bed and get up at the same time every day. Consistency reinforces your body’s sleep-wake cycle.

2. Get up if you are tossing and turning. If you don’t fall asleep within about 15 minutes, get up and do something relaxing, then go back to bed when you are tired. If you agonize about falling asleep, it can make the task more difficult.

3. Practice a relaxing bedtime ritual. Do the same each night to signal to your body it’s time to wind down. Take a bath or shower, read a book or listen to soothing music.

4. Exercise daily. Physical activity can promote better sleep. However, if you exercise too close to bedtime, you might find yourself too energized to sleep. If that’s the case, exercise earlier in the day.

5. Create a comfortable environment. Buy a mattress and pillows that feel right for you. Keep your room cool, dark and quiet. Consider using room-darkening shades, earplugs and a fan.

6. Avoid caffeine and alcohol, particularly in the evening and at night. Stop drinking caffeinated beverages six hours before bedtime and alcohol three hours before bed.

7. Turn off electronics. Experts recommend powering down at least an hour before hitting the sack. That applies to computers, television, cellphones, tablets and other electronic devices.

Why? Light promotes wakefulness. Photoreceptors in the retina sense light and dark, signaling a person’s brain about the status of the outside world and aligning his or her circadian rhythm to the day-night cycle. Light helps us be alert, dark helps us fall asleep. Studies have shown that even small electronic devices emit sufficient light to stimulate the brain and promote wakefulness.

What happens when you sleep

Both quantity and quality are important when it comes to sleep. If sleep is cut short, the body doesn’t have time to complete all of the phases needed for muscle repair, memory consolidation and the release of hormones that regulate appetite and growth, even in adults.

When you sleep, your body cycles between REM (rapid eye movement) sleep and non-REM sleep. The cycle typically repeats every 90 to 110 minutes. Non-REM sleep, which starts when you begin to doze, accounts for about 75 percent of your sleep.

There are four stages of sleep.

Oversleeping

Too much of a good thing — sleep, in this case — can be just as dangerous as not enough.

Scientists have found that adults who sleep more than nine hours each night are at higher risk for depression, stroke, diabetes, heart problems, memory loss and mental impairment.

Stage 1

This is light sleep, when you drift in and out of sleep and can be awakened easily. Physiologically, your eyes begin to move slowly and muscle activity wanes. During this stage, many people experiencing a sensation of falling and have sudden muscle contractions in response — the feeling of jumping awake. People awakened during this stage may remember fragmented visual images or snippets of conversations.

Stage 2

This is the official onset of sleep. Eye movements stop, brain waves slow, breathing and heart rate regulate, and body temperature drops. You become disengaged from your surroundings as your body prepares for deep sleep.

Stage 3

This is the deep-sleep stage, which is the most restorative. It is harder to rouse you, and if someone did, you’d likely be disoriented for the first few minutes after awakening. During this stage, there is no eye movement or muscle activity; your body is fully relaxed. Blood pressure drops, breathing slows, and blood supply to your muscles increases. As a result, tissue, bone and muscle growth and repair occurs, the immune system is strengthened, and energy is restored. Also, hormones essential for growth and development are released.

Stage 4

The first REM sleep period typically occurs about 70 to 90 minutes after falling asleep. Subsequent REM cycles repeat throughout the night, getting longer through your slumber. REM sleep accounts for about 25 percent of a person’s total sleep.

Muscles are turned off, meaning limbs temporarily are paralyzed, and the body becomes immobile and relaxed. But the brain is active, and dreams occur. When people awaken during REM sleep, they often describe bizarre and illogical dreams.

Breathing becomes more rapid, irregular and shallow; eyes jerk rapidly in different directions; heart rate increases, and blood pressure rises. REM sleep helps provide energy to the brain and body, and supports daytime performance.

Sources: National Sleep Foundation, Mayo Clinic, Harvard Medical School, National Institutes of Health