Healthy Brain, Happy Life (15 page)

From a neurobiological perspective, we know the most about the brain basis of mood from situations in which mood is altered—namely from the study of depression, one of the most common psychiatric conditions in first world countries like the United States. From studies of abnormal mood states, we know mood is determined by a widespread and interconnected group of brain structures together with interconnected levels of a set of well-studied neurotransmitters and growth factors. We talked about the role of the hippocampus in memory, and recent studies have shown that its normal functioning is also involved in mood. In addition, the amygdala, important for processing and responding to emotional stimuli, and the prefrontal cortex are both implicated in regulating our mood states. Furthermore, two other systems, which I describe in greater detail in later chapters—the autonomic nervous system including the hypothalamus (Chapter 7) and the reward circuit (Chapter 8)—are involved in regulating our mood. We also know that the appropriate levels of particular neurotransmitters are important for regulating mood. An influential theory of depression is that it is caused by a depletion of a category of neurotransmitters called monoamines. These include serotonin, whose low levels most of us associate with depression, but lowered levels of norepinephrine, another neurotransmitter, as well as dopamine are found in the brains of patients with depression. Therefore, the studies suggest that if you boost the levels of these neurotransmitters, you can boost mood.

Well, little did I know but I was getting a triple whammy of mood-boosting power with the intenSati workout. First, many studies have shown that not only does aerobic exercise improve measures of mood in subjects both with depression and without but that exercise boosts levels of the three key monoamines we know play a key role in mood: serotonin, noradrenaline, and dopamine. Besides these classic mood-associated neurotransmitters, exercise also increases levels of endorphins in the brain.
Endorphin
literally means “endogenous (made in the body) morphine.” It is a kind of morphine that has the ability to dull pain and provide feelings of euphoria. Endorphins are secreted by the brain’s pituitary gland into the blood, where they can affect cells throughout the brain that have specific receptors for them. Because endorphins are secreted into the bloodstream, they are categorized as a hormone; neurotransmitters, on the other hand, are released at synapses from the axon of the cells that synthesize them.

While most of us assume that endorphins are responsible for all or most of the high associated with some forms of exercise, the story is not as clear as all that. In fact, for many years there was a huge controversy in the neuroscience community (invisible to the popular press) over whether endorphins had anything to do at all with the so-called runner’s high. This was because, while there was good evidence that the level of endorphins increased in the peripheral bloodstream (that is, the bloodstream that courses through the body), it was not clear if exercise changed the level of endorphins in the brain, which is where they had to be working to produce the runner’s high. Only recently has a group in Germany provided evidence that running does activate the endorphin system in human brains and that the more profound the reported runner’s high, the stronger the activation. So neuroscience shows that a range of different neurotransmitters associated with mood and/or euphoria are increased with exercise and are likely causing at least part of the party mood caused by exercise.

The second mood-boosting whammy from intenSati comes from the spoken affirmations that are such a prominent part of this workout. A relatively large body of psychology experiments has shown that self-affirmations like the ones we were shouting to the rooftops in class help buffer people from a whole variety of different stressors, including peer-based classroom stress, rumination associated with negative feedback, and stress associated with social evaluation. One recent study reported that positive self-affirmations significantly improved mood in people with high self-esteem. We don’t know the brain and neurochemical changes associated with self-affirmations, but the behavioral evidence is quite clear that positive affirmations boost mood.

The third mood-boosting whammy of intenSati comes from the fact that during class, the physical moves that we perform are very strong and powerful; we are essentially in one power pose after another. The TED talk sensation Amy Cuddy, a social psychologist from Harvard, did a study in which she had some people pose in powerful positions with their arms behind their head and their feet up on a desk (the Obama pose) or with both hands leaning forward on a table in a pose of authority for just one minute and other people pose in nonpowerful positions, like sitting with the legs and arms crossed. The study showed that relative to the nonpowerful posers the power posers had increased levels of testosterone and decreased levels of the stress hormone cortisol in the bloodstream (after just one minute) as well as increased feelings of power and higher levels of risk tolerance. Indeed, recent studies in rodents confirm that exercise can increase testosterone levels in the blood, but other studies show that higher-intensity aerobic exercise
increases
circulating cortisol levels. These findings add to our knowledge of the powerful cocktail of brain and blood factors that can shift our mood after exercise.

This was also when I first started to see that while exercise is great for our bodies, when we make exercise both aerobic
and
mental—meaning you are fully engaged in the movement and/or feel passionately about it—we trigger another very powerful level of the mind-body connection. I call this
intentional exercise.
The key point is this: While the form of exercise I found in my gym was a fantastic example of intentional exercise, it is not the only one. I realized that you could make any workout intentional simply by bringing your own positive intentions, affirmations, or mantras to the class and focusing on those as you work out. Bring a positive affirmation like “I am sexy” or “I am graceful” to your next Zumba class. Choose a mantra like “I am strong” or “I am powerful” for a cardio/weight-training class or your next run. Adding your own personal affirmation or mantra to your favorite workout will do the same thing as what I experienced in the intenSati class. It will create the same positive feedback loop of affirmations and exercise, leading to good mood, leading to higher motivation, leading to higher levels of exercise, and leading to even better mood. You might need to play around with the kind of exercise you choose to optimize the effect. It has to be one you enjoy and that will allow you to get into the affirmations that really motivate you to do more. Try it out and see what works!

POWERFUL AFFIRMATIONS AND MANTRAS

People often tell me they can’t think of their own affirmations. Here are some to help inspire positive intentions during your own workout:

I am inspired.

I am grateful.

I am sexy.

I am confident.

I am Wonder Woman strong.

I am Superman strong.

My body is healthy.

My brain is beautiful.

I throw away the old and embrace the new.

I expand my comfort zone every day.

I was feeling great,
strong, happy, and motivated. I was making a powerful shift. Then I realized this shift in my mood was starting to change deeper things in me. While I thought I had high self-esteem, particularly around my work, I felt my exercise start to shift other parts of my self-esteem that had long been buried at the back of my closet, especially that part that was much more vulnerable in social situations. I looked better than I had in years and was in great shape, and my intentional exercise was starting to work on that negative part of my self-esteem in wonderful ways.

Yes, I had been a regular gym goer for several years by this point; but most of that time, I kept to myself at the gym. I came in, did my workouts with Carrie or in a class, and went home. With the positive effects of the intenSati class taking hold, I started making friends at the gym—maybe not lifelong BFFs, but friends nonetheless. It was quite a step for me because it was the first time I started making very exotic kinds of friends: non-scientists. It turns out, there was a whole world of people at the gym whom I had been standing next to in class for a couple of years; only with the influence of my intentional exercise, however, did I start to come out of my shell and begin talking to them. I met all sorts of new people, from stylists to actors to businesspeople to publicists. I found a new network of people to connect with, not just in the intenSati class but in all the classes I was taking. This new shift in my life started with fitness and weight, but it turns out that even more changes were a comin’.

Another noticeable shift came in a different area of my life: my teaching. Influenced by Marian Diamond and her wonderful teaching abilities, I have always loved and taken great pride in my teaching. I was as devoted to teaching as I was to setting up my lab in those early days as a new assistant professor at NYU, and I always brought great preparation, organization, and enthusiasm, if not a somewhat traditional approach, to the courses that I taught. Inspired by Diamond, I particularly loved teaching neuroanatomy and tried to bring a spark of interest to this rather daunting topic in the best way that I could. My efforts paid off because my teaching evaluations were always very strong.

But I can see now that all the shifts and changes that were happening in my personal life also affected my teaching in a similarly positive way. For example, one of the courses I teach to junior and senior neural science majors is called “Neurophysiology of Memory.” I have students read a series of carefully chosen papers, and we then go through the history of our understanding of how the cells of the hippocampus and related brain areas fire when we are learning or remembering something. I was looking forward to the class, but I wanted to get playful with my teaching; inspired by a class at the gym, I knew exactly what I wanted to do.

I was taking dance classes that often left me frustrated because I just could not learn the choreography as well as other people in the class. Granted, many of the other students were former or aspiring dancers, so I should not have been so hard on myself, but I was still frustrated. I realized that part of my problem was that I was trying to explicitly memorize the steps that the teacher was showing me using my favorite brain structure, the hippocampus. But then it hit me; I knew motor learning used different brain areas that were nondeclarative or unconscious. Think about it, you don’t have detailed conscious awareness of all the muscles you use for your golf swing. You learn it with practice in an unconscious way.

That was it! That was the answer! I was just using the
wrong
part of my brain to learn the dance! Now all I had to do was figure out how to use my basal ganglia instead of my hippocampus, and Alvin Ailey, here I come! I did stop trying to memorize the dance moves and just tried to focus on moving my body in the way the teacher was showing and kind of going with the flow, which definitely improved my choreography learning curve noticeably. This was a real breakthrough in my own personal understanding of how memory works. I knew theoretically the differences between the two memory systems, but this was personal, real life, and the realization really helped me dance better in class. I had to try to focus on the right brain system and stop trying to overuse my not-so-great declarative memorization skills.

Even more important, this breakthrough inspired a new lecture session in my “Neurophysiology of Memory” class, which I could not wait to do. The idea was to teach students about the two different learning systems (and the neurophysiological studies that had been done on these two systems), contrasting declarative memory for facts and events with unconscious motor system–based learning (for example, learning the physical movements used to play the piano or tennis). I wanted to give the students the same experience of discovering the difference between the two different types of memory, so I had them learn a dance routine in class. It was a speed-dial version of the discovery I made after many, many dance classes, but I thought I could pull it off.