How to stay awake and boost energy when you're sleepy

• To stay awake, you can drink more water, try some caffeine, or eat a healthy snack like fruit.
• Sunlight and exercise, like taking a brisk walk outside, can also boost energy levels.
• This article was medically reviewed by Julia Blank, MD, family medicine physician at Providence Saint John's Health Center.
• Visit Insider's homepage for more stories.

Experts recommend that adults get 7 to 9 hours of sleep each night, but for many people — especially those who work night shifts or irregular hours — that's next to impossible.

About one-third of Americans don't get enough sleep, and tired employees cost the economy billions of dollars each year.

While enough sleep is the best way to combat fatigue during the day, some other strategies that can help you stay alert include drinking more water, consuming a bit of caffeine, and getting plenty of natural light. Here's the best tips to stay awake.

What to eat and drink to stay awake

If you need to stay awake, start by drinking a big glass of water. "Dehydration commonly causes brain fog and fatigue," says Soma Mandal, MD, a board-certified internist in New Jersey.

• Fluids. Since your brain is about 75% water, being properly hydrated is essential to proper brain function. Even mild dehydration can impact your mental abilities, so be sure to drink enough fluid. How much do you need? Divide your weight (in pounds) by two to determine how many ounces of water you need. So, if you weigh 150 pounds, you should aim for 75 ounces of water per day.
• Caffeine. Next, consider some caffeine, which is a stimulant that boosts activity in your brain and central nervous system. Coffee is a well-known source of caffeine, says Erin Nance, MD. Nance says to skip soda or energy drinks that contain caffeine because the added sugar will result in a crash after an initial boost of energy. Instead, choose healthier options for caffeine consumption, like green tea, she says.
• Snacks. A small snack — rather than a large meal or no food at all — can also help boost alertness, according to a 2019 study done on night shift workers. The workers were split into three groups, and ate either a full meal, no food or a small snack containing 10% of their daily recommended calories. The snack group reported less sleepiness during their shift. Mandal recommends fruit, since you'll get the benefits of sugar, but with fiber that will help you avoid a sugar crash. Avoid simple carbs, such as white bread, chips or candy, since "these types of foods are inflammatory and can lead to fatigue and grogginess," she says.

Get outside and get moving

Exposing yourself to natural light is another great way to boost alertness. In fact, Vitamin D deficiency is often caused by a lack of sunlight, which can result in fatigue.

"Natural light can get absorbed through the skin, where the body can make vitamin D," explains Mandal. "Vitamin D is one of the vitamins that can help increase energy levels. Natural light can also reduce eye strain, which is also a culprit for fatigue and decreased alertness."

For example, research has found that increased office lighting can boost alertness among workers.

Moreover, just getting outdoors, even just for a brisk walk, is key in boosting alertness, Mandal says. A 2014 study found that people who climbed stairs, raising their heart rates to 50% to 70% of their recommended maximum, performed better on a cognition test immediately after the exercise. Mandal recommends walking to increase energy levels and stay awake longer.

"Sitting for long periods of time denies your body the cardiovascular challenge it needs to pump blood through your system," Nance says. "The brain needs oxygen to support the metabolism necessary to stay focused."

Napping and other tricks to boost energy

For some people, naps can help with energy levels. According to a small 2019 study of 17 physically active men, napping for 25, 35, or 45 minutes in the daytime after about seven hours of sleep all resulted in better performance on a five-meter shuttle run test.

Many people find other hacks to help keep themselves awake, like splashing cold water on their faces, listening to music, or using aromatherapy with peppermint or lemon scents, Mandal says.

In the end, it's worth trying a few of these strategies to gauge what works best for you, as everyone's body and energy levels can respond differently.

• Why am I always tired? The main causes of sleepiness and fatigue
• How melatonin can make you sleep better: what it is, how much to take, and the health benefits
• Is too much sleep bad? How oversleeping could signal something is wrong
• A consistent lack of sleep can potentially cause heart disease
• How to get better sleep with anxiety or stress, in 5 different ways
• Why depression makes you tired and how to deal with fatigue