As business owners, we understand what overwork feels like. We throw ourselves into growing and promoting our businesses, we devote ourselves to our customers and clients — and yes, we end up exhausted.

That tired feeling that weighs you down might come from any of several sources. Once you understand why you're so tired, you can start to make some changes to give you the energy you need to run your business. Take a look at some of the sources of exhaustion as well as some tips to boost your energy so you can accomplish what you set out to do.

What's Making You So Tired?

When we're honest without ourselves, we can usually pinpoint the reasons we're tired. But sometimes they're not so obvious. Generally, that fatigue you feel boils down to one of three reasons:

1. You're Not Taking Care of Yourself

Are you eating well, sleeping well, taking time for yourself? As entrepreneurs, sometimes we don't even know the answer to those questions — but the answers can have a profound effect on our energy level. Maybe you're giving yourself a boost with sweet snacks, relying on the sugar high to keep you going.

And then there's caffeine. Yes, that cup of coffee in the morning gets you going — but if you're drinking more four cups a day (that's the equivalent of two energy drinks, by the way), the crash you feel when the caffeine wears off can be exhausting.

How about your sleep habits? Do you stay up scrolling through social media and realize you're going to bed an hour (or two) later than you should? If you don't practice good sleep hygiene, you can't expect to arrive at your office with the energy you want.

2. You're Stressed

You might be proud of how many hours you work per week to keep your business thriving — but those long hours are the primary cause of your exhaustion. And when you don't give your body time to unwind, it forgets how to do relax. How many nights have you spent staring at the ceiling in an ending cycle of stress as you review everything that went wrong yesterday and all the things that might go wrong tomorrow.

Stress affects your body's hormones in a negative way, so the problem feeds on itself. When you're stressed, your body produces cortisol, often known as the "stress hormone" — and its presence in your system keeps you awake, which makes you more exhausted, which makes you more stressed — and the vicious cycle continues.

Of course, the workplace isn't the only source of stress. If your relationships or home life causes stress, or if your personal to-do list is piling up, you'll find yourself surrounded by negative emotions in all directions.

3. Your Body is Working Against You

We talked about cortisol, the stress hormone, above. But other hormonal imbalances can also make you fatigued and irritable. Estrogen, progesterone, melatonin and thyroid imbalances should all be treated by a physician. Various auto-immune diseases, such as lupus, fibromyalgia, Lyme disease, and Hashimoto's thyroiditis, can all affect your energy level. Once you've made the appropriate lifestyle changes, if you're still feeling regular exhaustion, don't try to diagnose yourself, but head to your doctor's office for diagnosis and treatment.

How to Boost Your Energy During the Work Day

Fortunately, there are proactive steps you can take to end fatigue and regain energy. Take a look at some small things you can do to boost your energy levels.

• Unwind before bedtime. Turn off your screens — TV, computer, and smartphone — at least two hours before you go to bed.
• Take breaks during the workday. Many people finding that taking just a few minutes for deep breathing and meditation helps refocus their mind and their energy.
• Clean up your sleep hygiene. Abstain from caffeine before the evening, and go easy on alcohol. Turn your bedroom into a haven, with blackout curtains and a noise machine if needed — and don't lounge on your bed outside of your normal bedtime.
• Hand off tasks other people can do. If you're working 60 to 80 hours a week, ask yourself how much of that time is spent doing things only you can do. Delegating routine tasks to others will help rejuvenate your energy and your mindset.
• Get some exercise. Climb the stairs to your office. Park as far from the front door as possible. Take a walk at lunch. Exercise releases all sorts of good chemicals that boost mood and energy.
• Get outdoors. Sometimes staring at the same four walls produces exhaustion (even if one of those walls is a window). Make sure you get outside your office for part of your workday each day.