It's no secret that exercise is good for both your brain and your body.

But the past decade has seen an explosion of research into just how transformative it can be, whether it’s improving academic performance in children, boosting mood and memory in adults, or even protecting us from cognitive decline . “It seems to be one of the most important things you can do for your brain,” says David Lubans at the University of Newcastle, Australia.

Understanding the Connection Between Exercise and the Brain

Scientists like Lubans are now turning their attention to how and why exercise has such powerful effects on the mind. What they’re discovering is revealing what really works and showing us how we can harness the brain-boosting powers of exercise.

One of the first pieces of evidence linking exercise and the brain dates back to the 1990s, when geneticist Fred Gage discovered that exercise could lead to the growth of new brain cells in mice.

Since then, studies have shown that exercise produces chemicals that facilitate communication between new brain cells and that it is one of the few things that can stimulate the growth of new brain cells in humans , particularly in areas of the cortex vital to learning, memory, and mood.

Exercise as a Treatment for Mental Health

Mood is a good place to start if you want to see how exercise can impact your brain.

As anyone who exercises regularly can attest, moving the body provides an instant tonic for the mind . Even a single session can leave people feeling more positive for hours and more energetic.

Chekroud’s study found that all types of activity were associated with a reduction in poor mental health days . The strongest link was for team sports, followed by cycling, aerobic exercise, and gym workouts. But even lighter activities like walking or doing housework mattered, reducing the number of poor mental health days by 17.7 percent and 10 percent, respectively. The benefits were comparable to, and often greater than, other predictors of good mental health, such as higher education or higher household income.

Strength training , such as lifting weights or doing push-ups, has also been found to reduce anxiety in adults, help ease symptoms of depression, and boost self-esteem.

Childhood and Old Age

Most research has focused on childhood and old age, since these are the periods when the greatest changes occur in the brain – and therefore also the periods when the influence of environmental factors is particularly strong.

During childhood, our brains are developing rapidly, building connections that allow us to master new skills . During this window, the brain is especially sensitive to the impact of movement. Inactivity is associated with poorer academic performance in children as well as lower scores on standard cognitive tests.

A small amount of exercise can make a big difference.

In 2009, Charles Hillman of Northeastern University in Boston and his colleagues were the first to show that if school-aged children around age 9 did a single bout of moderate exercise — walking for just 20 minutes on a treadmill — they saw almost instantaneous improvements in brain function, cognition, and academic performance, scoring better on math and reading tests than if they sat still.

Other research has found that when children ages 8 to 10 took a 15- to 20-minute walk or run before school, they showed better behaviors , such as listening or following rules, than on days when they didn't walk or run.

Preventing dementia

The cognitive effects of exercise are not limited to children and adolescents.

Research has found that staying active can improve all kinds of thinking skills in adults, including memory, concentration, and creativity, supporting the idea that taking time off from work to exercise could make us all more productive.

It could also be one of the best investments for our future.

“We’ve seen that exercise could potentially be one of the biggest factors in preventing Alzheimer’s disease and other types of dementia,” says Eef Hogervorst, who studies exercise and cognition at Loughborough University in the UK. And unlike a healthy diet and quitting smoking, which have the greatest impact on the brain if done before you develop symptoms of dementia, Hogervorst says, exercise is beneficial until you die .

Hogervorst emphasizes that exercise is one of the few things you can do to not only help prevent dementia, but also slow its decline if you’re already experiencing symptoms. In people with and without dementia, memory improves as early as 24 hours after a single resistance band exercise session, and results are even better after several weeks.

One of the most familiar explanations is that "what's good for the body is good for the brain."

The brain is voracious, burning a tremendous amount of energy and requiring a constant supply of oxygen and nutrients to be delivered through the circulatory system. Exercise helps keep this network of blood vessels healthy and blood pressure low.

The important thing is to move

When it comes to choosing the best exercise for you , you may want to consider who you do it with. Chekroud and his colleagues found team sports to be the most beneficial for mental health , which makes sense since social activity promotes resilience to stress and reduces the risk of depression. The social side of team sports may also help reduce the social withdrawal and feelings of isolation that often go hand in hand with depression and other mental health issues.

There is also a school of thought that says the best exercise is one that is cognitively stimulating or, to put it another way, one that makes you move and think at the same time, like rock climbing or martial arts.

This may have roots in how our ancestors evolved to be active. When they began walking on two legs and hunting for food over long distances, the simultaneous demands of navigating, communicating, and scanning the environment while moving would have placed a huge new cognitive load on our species.

Finally, whatever you choose, make sure it's something you enjoy.

Not surprisingly, studies show that people who are forced to exercise in laboratory experiments experience a decline in their mood.