How to Power Through the Day Without Any SleepAlthough sleep is important to productivity, here's how to power through the day even without a full night of z's.

We all know the importance of getting a good night's sleep. Lack of sleep can cause anxiety, irritability and affect your ability to retain information, all impairing your productivity. But as all busy entrepreneurs know, sometimes getting a full night of shut-eye just isn't possible, leaving you with no choice but to try to power through the day on little rest.

Open your curtains.

Getting exposure to light as soon as you wake up is important for giving you energy to kick-start your day. "Sunlight will decrease the release of melatonin, a hormone that makes us sleepy," says Steve Orma, clinical psychologist and co-author ofStop Worrying and Go to Sleep: How to Put Insomnia to Bed for Good. To help fight that sleepy feeling, try working by a window or take frequent breaks to get outdoors. "Exposure to natural light throughout the day would help keep you more awake," says Orma.

Take a cold shower.

Dr. Mark Kovacssays a 30- to 60-second cold shower stimulates adrenaline (your body's fight or flight response), getting your nerves ready for the day.

Breathe.

Breathe in through your nose slowly for five seconds, then exhale through the mouth for two seconds. Repeat this exercise five times. "This works on simultaneously decreasing and increasing heart rate," says Kovacs.

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Avoid having a power lunch.

If you're short on sleep, eating smaller meals throughout the day can help you sustain your energy. "When you're already limited in sleep, taking any large meals is not a good idea," says Kovacs, as eating a large meal puts a strain on your body's organs, causing you to feel even more tired.

Power up with protein.

While it can be tempting to go for a coffee-and-donut combo,Dr. Jo Lichten, author of重启:如何启动你的精力,专注和公关oductivity说,一顿饭的20-35g蛋白质将帮助keep you more alert than a high carb meal which will simply give you an initial energy spike followed by an immediate crash. Eggs, Greek yogurt or a piece of meat about the size of the palm of your hand are good healthy options for a pick-me-up snack.

Don't fill up on coffee.

Hanging around the coffee machine all day isn't going to do much to give you sustained energy to make it through the day. While you may think gulping down caffeine will help you feel more alert, too much caffeine can cause you to feel jittery and anxious rather than focused. Dr. Lichten says 50mg to 100mg of caffeine is the optimal dose for alertness and focus. Opt for a short cup of coffee every four hours during the day, stopping at 4pm to prevent another poor night of sleep.

Power up with a caffeine nap.

You may not think caffeine and a nap go together, but experts say a cup of coffee before a nap is the key to boosting your brain power. Kovacs recommends ordering a double espresso, set your alarm for 25 to 30 minutes and take a nap. "Once you awake the caffeine will have started to work and you can push through the remainder of the day," he says. The reason the caffeine-nap combo is so effective is that caffeine takes about 45 minutes to be absorbed, so taking a nap while the caffeine is making its way through your system allows you to awake when the alertness effect of the caffeine has kicked in.

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