The Biological Reason to Practice Gratitude To help improve your mood and not wake up anticipating stress, try this.

Excerpted from Game Changers, by Dave Asprey.

A top expert who taught me a lot about gratitude is Dr. Elissa Epel, who is a professor at UCSF who studies how stress can impact our biological aging via the telomere/telomerase system and how meditation modalities may buffer stress effects and boost physical and spiritual well-being.

Related: When You're Feeling Unmotivated, Remind Yourself to Be Grateful

Dr. Epel told me about a study she did with the mitochondria researcher Dr. Martin Picard at Columbia University. They examined participants' blood to determine the activity of their mitochondrial enzymes. These chemicals play an important role in producing energy for your cells. Dr. Epel and Dr. Picard found that as a group, caregivers -- such as mothers who had a child with a chronic condition -- had reduced enzyme activity. Yet, within that group there were some notable exceptions.

To learn the origin of these differences, the researchers took an inventory of the participants' daily lives and asked them questions such as: From the moment you wake up, how much are you looking forward to the day? How much are you worrying about the day? How happy are you? How stressed or anxious are you? They were looking not just for the participants' affect and emotion but for their appraisals of what was going to happen to them, good or bad. In other words, were they locked in a cycle of always anticipating a threat, or did they also experience hope and gratitude? They checked participants' mitochondrial enzymes in the morning, after a moment of stress, and then again in the evening. They found that the people with the most mitochondrial enzymes had a higher positive affect when they woke up and when they went to bed, especially around bedtime. It was their recovery mood and whether or not they held onto the residue of everything that happened to them throughout the day that determined how well their mitochondria were functioning.

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To help people improve their mood and not wake up anticipating stress, Dr. Epel suggests that they think of something they are grateful for in the evening before bed. That simple gratitude exercise could potentially boost the participants' mitochondrial enzymes and made them happier.

Although it's understandable that mothers of sick children might be prone to fearing the worst, Dr. Epel explains that many of us anticipate moments of stress without even realizing it. The question is: Are you carrying that perceived danger or threat with you throughout the day and ruminating over it? Are you putting yourself into a state of fight or flight by anticipating stress before it happens? Or are you bathing yourself in cues of safety by feeling grateful? An easy way to tell if you are spending your days anticipating threats is by paying attention to how you feel in the evening. At night, your mood is really important because it reflects how well you've recovered from your stress. How positive is your mood when you get home from work in the evening and before bed?

Several years ago, I instituted a gratitude practice at Bulletproof. Our weekly executive team meetings begin with each team member sharing what he or she is grateful for. Sometimes it's a big win at work. But, most often it's time with family, a volunteer project or maybe a Seahawks win. Starting a meeting with gratitude makes for a more powerful interaction and builds connection among the team members. I see it as an act of service I can offer to the people who so passionately support the company's mission: to help people tap into the unlimited power of being human.

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I value gratitude so much that I don't save it for Team Bulletproof. Every night before bed since my kids were old enough to talk, I've been asking them to relate an "act of kindness," something they did that day to help another person. Their vagal tone increases when they recall something nice they've done. We follow with a nightly gratitude practice. Lana and I ask them for three things they're grateful for. Sometimes it's a little thing, such as being grateful for having had grass-fed rib eye for dinner. (I love having foodie kids!) But, sometimes it's profound. Once when my son was five, he got a strange look on his face and said, "Daddy, I'm grateful for the Big Bang because without it there wouldn't be anything." Then he rolled over and happily went to sleep with his nervous system calm and his mitochondria running at full power. It works for adults, too. Try it.