Shortform Mini Book Guide: "Spark"

3 Lessons and an Action Plan

What if the key to sharper thinking, better mood, and lifelong mental health lies in your running shoes?

In Spark, John Ratey argues that while we all know exercise is great for the body, its actual, evolutionary purpose is to strengthen your brain. But in today’s sedentary world, it’s easy to forget that we’re made to move, and our brains are suffering from lack of movement, leading to cognitive decline and a rise in mental health disorders—and even measurable brain shrinkage.

In this Mini Book Guide, we’ll outline the basics of Ratey’s advice on using exercise to think better, feel better, and live better. For a deeper summary—plus analysis of his ideas—check out our complete guide.

Lesson 1: We’re Both Brains and Brawn

To survive, our ancestors had to not only be physically strong, but they also had to read and respond to their environment with insight, knowledge, and innovation. So, our bodies and brains evolved in concert to support each other in a virtuous circle.

Lesson 2: We Need to Move

Today, the neurological systems our ancestors used to hunt and gather are the ones we use for sedentary activities like computer programming. But while we no longer share their reasons for moving, we still share their need to move on a fundamental, biological level.

A Chicago high school unwittingly proved the link between moving and thinking when they revamped their PE program and their students suddenly shot to the top of global rankings in reading and math.

Research hints at why this is: Exercise has been shown to prompt neurons to sprout new branches, and MRIs reveal that after three months of exercise, the hippocampus—the brain’s memory region—can increase neuron production by 30%.

Lesson 3: Acute Stress Is Good

Exercise works its magic by providing short-lived, acute stress, prompting our bodies’ repair responses to clean up harmful toxins on a cellular level. This boosts neurological activity.

Exercise not only helps you learn and think better, it also helps manage a host of mental health struggles, including depression, anxiety, addiction, and ADHD. It has also been shown to help slow the cognitive decline that comes with aging.

(Shortform note: In Brain Rules, John Medina writes that the evolutionary reason acute stress improves brain function—like memory and problem-solving—is that we needed to think clearly and insightfully when faced with a danger, or we were far less likely to survive it.)

Action Plan

Ratey writes that the best type of exercise for optimizing brain function is aerobic exercise. It increases blood flow, spawns new neurotransmitters, and forms new blood vessels that bring oxygen to your brain. To get the most out of your efforts:

• Vary your workouts between low-, medium-, and high-intensity activities—for example, switch between walking, jogging, and running.
• Start slow—people who jump in at high-intensity levels often drop their routines because they end up feeling bad both physically and emotionally.
• Choose activities you enjoy—if you like to bike, do that.
• Exercise with others to increase the likelihood you’ll stick with it. For example, join a running club or pickleball group.

(Shortform note: In Awaken the Giant Within, Tony Robbins suggests you start with a moderate-intensity aerobic exercise routine that you keep up for two to eight months. Laying that groundwork will prepare you for higher-intensity workouts.)

Want More?

In our complete guide to Spark, we further discuss the evolutionary origins of the mind-body connection, how exercise strengthens your brain, and how you can incorporate aerobic activity into your life. Along the way, we look at advice from other health experts and update some of the scientific findings Ratey explores.