Exercise can be effective at reducing symptoms of depression among people with the condition, according to a new review of studies published in The Cochrane Library, but researchers say more studies are needed on the relationship between depression and physical activity.

A team from the University of Edinburgh examined 39 past studies on depression and exercise, which included 2,326 people with depression, to find that exercise moderately benefited depression symptoms. However, “we can’t tell from currently available evidence which kinds of exercise regimes are most effective or whether the benefits continue after a patient stops” exercising, study researcher Gillian Mead, of the university’s Centre for Clinical Brain Sciences, said in a statement.

The researchers also found studies that suggested exercise was as good as antidepressants or therapy for depression, but the quality and size of those trials was both low and small. When researchers looked only at what they considered high-quality trials — six of the trials met their criteria — the association between exercise and decreased depression symptoms was weakened.

Of course, research has shown that exercise can positively affect the brain in so many other ways, beyond potentially decreasing symptoms of depression. Here’s some ways exercise can do your brain good:

1. It Sharpens Thinking

Earlier this year, Dartmouth researchers added support to mounting evidence about the way that exercise affects learning and mental acuity: it boosts the production of “brain derived neurotrophic factor” — or BDNF – a protein that is thought to help with mental acuity, learning and memory.

2. It May Alleviate Childhood ADHD Symptoms

In the same Dartmouth study, the researchers discovered that, thanks to the BDNF boost, exercise also helped to alleviate ADHD-like symptoms in juvenile rats. Since BDNF is involved in the brain’s development and growth of new cells, the effect was more profound on the younger rats, with their still-developing brains and more rapid cell turnover, compared to adult rats.

3. It Helps You Learn New Tricks

Even one exercise session can help you retain physical skills by enhancing what’s commonly known as “muscle memory” or “motor memory,” according to new research published in PlosOne.

As the New York Times reported, men who were taught to follow a complicated pattern on a computer and subsequently exercised were better able to remember the pattern in subsequent days than the men who didn’t exercise after the initial squiggle test.

4. It Supports Problem-Solving

In one study, mice that exercised by running not only generated new neurons, but those neurons lit up when the mice performed unfamiliar tasks like navigating a new environment.

5. It Helps Alleviate Symptoms Of Depression

When you exercise, your pituitary gland releases endorphins to help mitigate the physical stress and pain you are experiencing. But those endorphins may play a more important and longer-lasting role: they could help alleviate symptoms of depression, according to a Mayo Clinic report.

6. It Reduces Stress

Although exercising raises our levels of cortisol — the hormone that causes physical stress and is even associated with long-term memory impairment — its overall effect is one of a stress reducer. That’s because exercise increases the body’s threshold for cortisol, making you more inured to stressors.

7. It Helps Delay Age-Associated Memory Loss

As we get older, an area of the brain called the hippocampus shrinks. That’s why age is associated with memory loss across the board. However, profound memory loss — such as in dementia and Alzheimer’s disease patients — is also contributed to by accelerated hippocampus shrinking. Luckily, the hippocampus is also an area of the brain that generate new neurons throughout a lifespan. And, the research shows, exercise promotes new neural growth in this area.

Source: Huffington Post
September 15, 2013