Book SummarySpark, by John Ratey

1-Page Summary1-Page Book Summary of Spark

In Spark, John Ratey argues that exercise is not only good for the body, but it’s also good for the brain. Your brain is the dominant control center of your body, and its health directly affects, among other things, your mood, your attention, and your ability to learn. Ratey argues that your overall physical well-being is so intimately linked to brain function that maintaining it should be a top priority, and he hopes to convince us to make exercise a routine part of our lives.

Ratey is an associate clinical professor of...

Spark Summary Humans Are Built to Move: The Mind-Body Connection

Ratey argues that our brains are optimized by exercise because of the way humans evolved. When our ancestors ran down their prey in prehistory, their bodies and brains worked in concert. They not only had to sustain high levels of physical exertion, but they also had to read and respond to their environment quickly and accurately to survive. The brain and body, therefore, became well-conditioned to support each other in a virtuous circle.

Today, our brains still operate as our ancestors’ did. The same neurological systems they used to hunt and gather are the ones we use to program computers, and our minds still function best in a mode of persistent activity. However, in our modern era we no longer face the same challenges our ancestors did. We may not share our ancestors’ reasons for moving, but we do share their need to move on a fundamental, biological level.

**The Evolutionary Origins of...

Spark Summary Exercise Helps Us Learn

Ratey was inspired to study the connection between exercise and the brain after reading about Chicago’s Naperville public high school. Their novel fitness-first approach to gym class focused on getting students moving through regular exercise. A direct result of this improved fitness was significant gains in student performance. In a 1999 standardized test comparing Naperville students’ science and math knowledge with that of students from different countries, Naperville finished first in the world in science and sixth in math. Ratey concluded that the school’s focus on physical health was in large part the reason for their academic success.

Correlations Between Physical Activity and Academic Performance

Ratey’s conclusion that Naperville’s gym class model improved academic performance is supported by recent evidence—indicating that Naperville wasn’t a fluke.

In the time since the publication of Spark, national surveys by the Centers for Disease Control (CDC) have found significant correlations between physical activity and academic performance. A collection of ten intervention studies showed significant improvements in [academic performance as well as...

Spark Summary Exercise Regulates Our Stress Response

In addition to helping us learn, Ratey believes exercise has a powerful role in controlling the brain’s stress response system. To help readers understand this, he first offers a clear definition of the term stress.

Ratey defines stress as anything that initiates activity at the level of our cells. By this definition, our environments present countless stressors. For example, when we move, we stress both our muscles and the brain cells involved in controlling that movement. When we eat vegetables such as eggplant, our cells activate as they work to process toxins the plant has created to protect itself. When we hear an unexpected noise, our brains initiate a stress response as they work to assess the source of the noise and whatever threat it might pose.

(Shortform note: Another biological understanding of stress is that it’s anything that threatens homeostasis. Homeostasis is a state in which the body’s physical systems are in balance. So anything that disrupts that maintenance is a stressor.)

Under this narrow, biological definition, stress is neither inherently good or bad; it’s a fundamental...

Spark Summary Exercise Improves Our Mental Health

In this section, we’ll explore Ratey’s theories on how and why exercise benefits our mental health. We’ll first discuss neurotransmitters, which are largely responsible for psychiatric well-being, and then we’ll briefly touch on the various mental health conditions Ratey addresses, summarizing the main ways exercise helps. In each case, Ratey refers to the science and to stories from his clinical practice to make his point.

(Shortform note: Defining stress narrowly, in terms of cell biology, positions stress as a through-line in all the mental health concerns Ratey goes on to discuss. He isn’t as explicit about this as he could be, but bear in mind that each condition has some form of stress as a component—whether it’s a cause, a symptom, or some combination of the two. Accordingly, the way exercise combats the negative effects of stress generally applies to the other concerns he explores, such as anxiety, depression, and so on.)

Exercise Balances Neurotransmitters in the Brain

Neurotransmitters are chemicals that regulate the signals passing along the brain’s neural network.** When there's an imbalance of neurotransmitters we can experience difficulties such as...

Spark Summary Two Special Cases: Aging and Women’s Issues

We’ve seen how exercise helps us learn, regulate stress, and maintain mental health. Two significant consequences of this that Ratey discusses are that exercise protects the aging brain and helps regulate the unique hormonal fluctuations women face over the course of their lives.

Getting Old

For all of us, Ratey contends that the toll a lifetime of stress takes on the brain becomes hard to escape. Characteristic features of aging, such as cognitive decline, depression, and dementia, are at least partially caused by the body’s cells being worn down by the stressors of life.

Ratey argues that as your body becomes equipped to handle stress through exercise, it becomes better able to preserve its resources against the negative effects of aging. For example, as neurons wear out in the brain, the neural network thins—exercise counteracts this loss by supporting neuroplasticity and neurogenesis.

(Shortform note:...

Spark Summary Building a Routine and Making It Stick

We’ve seen numerous ways exercise supports brain health and contributes to our overall well-being—whether we’re facing anxiety, addiction, depression, or simply the desire to grow and learn, exercise helps.

In this final section of the guide we’ll look at the recommendations Ratey offers for building exercise into our life routines.

We’ll see:

• What form of exercise is best for reaping the benefits Ratey explores
• What your maximum heart rate is and how to use it to determine your most effective workout
• Some ideas for incorporating exercise into your daily routine

Aerobic Exercise Is Best

Ratey argues that not all forms of exercise are equally effective for optimizing brain function. Studies show that aerobic exercise is best. This isn’t to say that other forms of exercise aren’t beneficial, it’s just that aerobic exercise is currently understood to be optimal for tapping into the benefits we’ve explored.

(Shortform note: Researchers have demonstrated that both endurance exercise (e.g. running) and resistance exercise (e.g. weight lifting) [increased the release of factors such as brain-derived neurotrophic factor and [restricted term]-like growth...

Shortform Exercise: Take Action

At this point, we’ve seen numerous reasons to incorporate regular exercise into our lives. If you are like most other people and struggle to exercise regularly, let’s take a moment to consider how you can take action.

Think of an aspect of your mental life that you think could benefit from the effects of exercise on the brain. Do you struggle with depression, stress, lack of focus, or anxiety, for instance? Write about your most recent memories of a time when such a state of mind impacted your daily life.