Two very different circumstances might cause you to search for ways to have more energy.

One is if you’re generally feeling rundown; there are many possible causes for that. They include age, medical conditions or illnesses, depression, hormone imbalances, and nutritional deficiencies.

A long-term decline in normal energy levels almost always calls for a visit to a healthcare and/or mental health professional before taking other steps.

The other type of energy deficiency? Most of us are familiar with that one.

It’s the problem we have to deal with in the morning, when we were drinking alcohol the night before and haven’t gotten a good night’s sleep. It’s the problem when the boss tells us we have to work late for the third night in a week. It’s the problem that leads to exhaustion after a few days of juggling complicated work and family issues.

Those situations don’t call for medical advice. They call for a quick energy boost that helps you fight fatigue.

We’ll discuss long-term energy in a bit, but let’s talk first about how to have more energy in a hurry.

We’ll start with the method that more than one-third of all Americans between the ages of 18 and 49 rely on. That’s right, energy drinks.

1. Energy Drinks

The primary reason why energy drinks are able to provide a quick energy boost is no secret: it’s caffeine.

The most popular energy drinks contain between 115 and 300 milligrams of caffeine, which is anywhere between three and ten times the amount of caffeine that there is in a can of soda.

Caffeine provides an immediate pick-me-up that peaks in an hour and can last several more. A lot of caffeine provides an even more powerful boost – but it’s important to not overdo it. Once you get more than 400mg of caffeine a day you’re risking caffeine toxicity, which typically causes jitters and insomnia, and possibly even headache, anxiety, increased heart rate and chest pain.

There are other supplements in energy drinks, of course. Collagen and ginseng can contribute to alertness, focus, muscle recovery and mood, and B vitamins may help the body best utilize the glucose it gets from dietary carbs.

One other ingredient you’ll find in almost all energy drinks is sugar – and lots of it. That’s a double-edged sword, though.

Sugar doesn’t really increase available energy. It elevates mood, which is why you get the well-known “sugar boost” after half an hour or so. Within an hour, however, sugar actually slows the body’s energy production, which causes the equally well-known “sugar crash.”

Put all of that together, and you’ll understand why the energy drinks that give you quick, effective energy contain caffeine but not sugar. We happen to like Super Energy from the people who produce Super Coffee; they use monk fruit extract and stevia instead of sugar, for a longer-lasting supply of energy.

What about energy shots? They do basically the same thing as energy drinks but in a much smaller drink, making the danger of overdoing the caffeine even greater.

2. Coffee

Most people who don’t reach for an energy drink when they’re fighting a lack of energy reach instead for a cup of coffee.

An eight-ounce cup contains about 90 milligrams of caffeine, much less than a powerful can of Monster, Bang or Rockstar. However, coffee’s temporary ability to ease tiredness and boost focus is familiar to tens of millions of us, whether we’re trying to shake off sleepiness in the morning or combat mid-afternoon low energy levels.

If you prefer tea, it’s a poor second choice. Tea is just as good for your health as coffee (both have been linked to a lower risk of heart disease, for example) but it contains less than half the amount of caffeine. Its energy boost will last for a much shorter period.

3. A Glass of Water – or Two

This won’t get everyone energized, but you’d be surprised how many peoples’ lack of energy is caused by not drinking enough water.

Drinking water every hour or two can prevent dehydration from cropping up and bringing you down. But downing a couple of glasses can quickly relieve the decrease in energy caused by poor hydration. Even walking to the fridge or water fountain can help wake you up a little.

Speaking of which…

4. Exercise

If you need more energy during the workday, the boss probably isn’t going to let you head to the gym for a workout whenever you’re feeling tired.

That’s OK. Taking a ten-minute break for a brisk walk outside can work wonders. A few minutes of yoga or just pacing around the office while thinking about a thorny problem will usually help as well.

That’s because any type of exercise delivers oxygen-rich blood and nutrients to the heart, brain, muscles and other parts of the body. Extra oxygen helps the cardiovascular system and lungs work more efficiently, providing extra energy.

And needless to say, physical activity is also great for overall health.

5. Have a Snack – But Not Just Any Snack

Grabbing a candy bar from the machine might perk you up, but not for long.

We’ve already mentioned why anything loaded with sugar will give you the illusion of extra energy for a little while but will quickly lead to a sugar crash.

Instead, snack on a combination of carbohydrates and protein. It could be crackers and cheese, peanut butter on a slice of bread (whole grains are best), a few handfuls of pistachio or macadamia nuts (they contain lots of both macronutrients) or a protein bar.

Why carbs and protein? Hunger makes a problem with low energy worse, so protein helps keep you full. Carbs provide your body with additional energy.

(And to prevent hunger from tiring you out during the day, the best gift you can give yourself is a good breakfast that includes protein, fiber, and fruit.)

6. Scents Make Sense

There’s a good reason why experts suggest aromatherapy for enhanced energy. Peppermint, spearmint, lemon, eucalyptus and rosemary are among the essential oils that have been shown to relieve fatigue and improve focus.

You may not be somewhere where you can easily fire up an essential oil diffuser, but even sniffing a stick of cinnamon or chewing some peppermint gum can work as energy boosters, reviving flagging attention and providing a brief energy surge.

7. Breathing Exercises

Mindfulness and meditation are great, but those aren’t the only ways that controlled breathing can make you feel better. Just one minute’s worth of deep breathing increases the amount of oxygen in your blood, reduces your heart rate, allows your body to work more efficiently, and relieves stress – giving you the extra energy you need to stay alert and focus.

Here’s a one-minute breathing exercise that can do the trick. Slowly take five deep breaths, with each inhale lasting two seconds. Each time you breathe out, increase the length of the exhale by one second. The first exhale will last two seconds, the second will last three seconds, and so on.

A minute later, you’ll feel more rejuvenated and energetic.

8. Open the Shades

Studies have shown that the amount of light exposure people receive is directly related to their vitality. If you customarily work (or live) in a dark room, that environment can negatively impact your energy level.

Open the shades or blinds, or if that’s not possible, turn on more lights. Even better, go outside for a few minutes if the sun is shining. It could vastly improve your mood and productivity.

9. Take a Nap

We know that most people aren’t fortunate enough to be able to lie down for a power nap whenever they feel their energy flagging. If you’re one of the lucky ones, though, a 20-minute nap is enough to recharge your batteries.

Don’t nap for much longer than that, however. Once you get into a deep sleep you’ll feel drowsy or sluggish when you wake up.