The alarm goes off. You get dressed, grab your coffee, and head to work. But by lunchtime, you start to feel disorganized. You reread emails because you lack focus and mental clarity.

There's nothing worse than brain fog. In addition to stress and lack of sleep, it can be caused by the immune system creating an inflammatory response in the brain. This can lead to symptoms like poor concentration and memory, or difficulty making decisions.

As a neuroscientist, I study the causes of brain fog and forgetfulness. To avoid them, here are four things I never do:

1. I never let my body get tense for too long.

Even if you think you're relaxed, your body may be physically tense (e.g., stiff neck, back or shoulder pain). This can be a result of stress from things like unfinished tasks or looming deadlines.

So when I notice that my body is tense, I immediately do an exercise called "box breathing":

1. Inhale through your nose as you slowly count to four seconds.
2. Hold your breath for a count of four seconds.
3. Exhale through your nose, releasing all the air from your lungs, as you slowly count to four seconds.
4. Hold your breath for a count of four seconds.
5. Repeat for at least four rounds.

Box breathing is a simple way to help calm your brain. Studies also show that it can reduce levels of cortisol, which is the chemical produced when the body is under stress.

2. I never use screens one hour before bedtime.

As tempting as it might be to scroll through Instagram or watch TV before bedtime, these activities can be too stimulating for the brain.

Instead, I try to read a book before turning out the lights. If that doesn't help me sleep, I do a "relaxation body scan," squeezing and releasing muscles — starting at my toes and all the way up to my head.

Ideally, we need about eight hours of sleep a night. More than that can lead to a depressed mood, and less than that doesn't give the brain enough time to rest and reset.

3. I never load up on glucose.

If your gut isn't healthy, your brainpower can falter, too. I strengthen my gut-brain axis by maintaining a diet rich in hydrating foods, healthy fats and digestible protein.

Most important of all, I try to avoid sugar. Your brain uses glucose (sugar) as fuel, but refined carbohydrates like high fructose corn syrup found in sodas are not good sources of fuel. Your brain gets a burst of too much glucose, then too little.

This can lead to irritability, tiredness, mental confusion, and impaired judgment.

I also eat foods rich in magnesium — whole grains, leafy greens, dried beans and legumes — to help regulate my mood and sleep cycle. And I make sure to have my last caffeinated drink of the day before 10:00 a.m.

4. I never go a day without meditating.

I meditate for at least 12 minutes a day.

Doing this at nighttime can help mitigate brain fog the next day:

1. Remove all distractions from your room.
2. Sit or lie down in a comfortable position.
3. Take deep breaths.
4. Quietly observe your thoughts.
5. Whatever thoughts come, simply acknowledge them return your focus to your breathing.

If you don't like to meditate, you can do a mindful activity such as cooking or taking a quiet walk.

I also recommend coming up with a mantra that you can say in the morning, like: "Brain fog is a state of mind. I will go to bed early tonight and be fine tomorrow."

By articulating your goals to yourself out loud, you can start to be more intentional about changing your habits. And through that repetition, your brain and body will start to follow suit.

Dr. Tara Swart Bieber is a neuroscientist, medical doctor and senior lecturer at MIT Sloan. She is the author of "The Source: The Secrets of the Universe, the Science of the Brain," and hosts the podcast Reinvent Yourself with Dr. Tara. She works with leaders to help them achieve mental resilience and peak brain performance, improving their ability to manage stress, regulate emotions and retain information. Follow her on Twitter and Instagram.

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