Exercise for improved memory and cognition

We all know exercise is essential for staying fit, but it can also help stimulate our brains. The following guidelines will show you how exercise can help improve memory function and cognition.

When you work out, whether it's walking through a forest or lifting weights in a gym, you're doing more than just strengthening muscle. You're also stimulating numerous areas in your brain and central nervous system, each of which controls one tiny portion of the movement.

Plus, you're stimulating the release of a variety of chemicals, including human growth hormone (HGH). Yes, this is the same hormone given to kids who don't grow; the same one that certain "anti-aging" doctors give to patients at their clinics, even though it's usually illegal to use it for that reason.

Among its youth-promoting benefits, HGH triggers a hormonal and biochemical cascade that releases brain-derived neurotrophic factor (BDNF), a hormone that helps your brain sprout new synapses, or connections between neurons. One study of 59 healthy but sedentary people ages 60 to 79 found that working out aerobically for six months (and we're not talking about marathon training!) increased their brain volume, an improvement missing in a control group that didn't work out. It's probably why several studies find that regular physical activity significantly slows mental decline in people who already have Alzheimer's or other forms of dementia.

It's also why the more BDNF you have circulating in your brain, the greater your ability to learn and remember stuff. The less BDNF, the less learning sticks.

We've fallen away from our genetic tendency to be physically active nearly 100 percent of the day, and the resulting loss of BDNF and the neurotransmitters it affects, including serotonin, contributes to our current high rates of obesity, forgetfulness, dementia, and depression.

Another benefit:

• High levels of BDNF control appetite and reduce the risk of obesity.
• They also stimulate the release of neurotransmitters in the brain, such as serotonin and dopamine, that control mood and play a role in depression.

Scientists suspect that these exercise-induced BDNF boosts may partially explain the benefits of exercise on people with depression. Upping your BDNF levels doesn't take much; for rats, a week of running on a wheel is enough. In humans, a single high-intensity workout triggers results. Of course, the increase is short term, which is why regular physical activity is so important.In fact, some researchers suggest that what we think of as "age-related" mental decline — memory loss, some slowing of our thinking, etc. — is actually "revenge of the sit."

Now, we're not suggesting that you buy yourself a human-size hamster wheel or begin testing your blood levels of BDNF after every two-mile jog. Focus on the visible benefits.

• Walking briskly for 45 minutes three days a week for six months can make a huge difference in the kind of mental acuity that allows you to be more attuned to the world around you.
• It can even reduce the effects of a traumatic brain injury if begun two weeks after a serious concussion.

So stick with an exercise program for just three months and see what kind of memory, learning, and decision-making benefits you get from it!