By Dr. Mercola

There are many reasons to exercise. Protecting your brain health and optimizing your thinking ability is one of them. In fact, there's compelling evidence that exercise produces large cognitive gains, improves memory, and helps fight dementia.

For example, a 2010 study¹ on primates revealed that regular exercise helped the monkeys learn new tasks twice as quickly as non-exercising monkeys, and researchers believe this might hold true for people as well.

Exercise helps protect and improve your brain function by:

• Improving and increasing blood flow to your brain
• Increasing production of nerve-protecting compounds
• Improving development and survival of neurons
• Reducing damaging plaques in your brain
• Altering the way these damaging proteins reside inside your brain, which appears to slow the development of Alzheimer's disease

Lifting Weights Boosts Memory

Strength training in particular has been shown to have a very beneficial impact on brain function and memory. In one study² — featured in the video above — just 20 minutes of strength training was found to enhance long-term memory by about 10 percent.

In this experiment, 46 volunteers were randomly assigned to one of two groups — one active, and one passive. Initially, all of the participants viewed a series of 90 images. Afterward, they were asked to recall as many images as they could.

Next, the active group was told to do 50 leg extensions at personal maximum effort using a resistance exercise machine. The passive participants were asked to let the machine move their leg, without exerting any personal effort.

Two days later the participants returned to the lab, where they were shown a series of 180 pictures — the 90 original photos, plus 90 new ones. Interestingly, even though it was two days since they performed the leg extensions, those in the active group had markedly improved image recall.

The passive control group recalled about 50 percent of the original photos, whereas the active group remembered about 60 percent of the previously shown images.

As reported by The Epoch Times:³

"Our study indicates that people don't have to dedicate large amounts of time to give their brain a boost,' says Lisa Weinberg... who led the project.

Although the study used weight exercises... resistance activities such as squats or knee bends would likely produce the same results. In other words, exercises that don't require the person to be in good enough to shape to bike, run, or participate in prolonged aerobic exercises..."

The Intriguing Link Between Leg Power and Brain Function

Another recent study supports these findings, and suggests that working your leg muscles helps maintain cognitive function as you get older. According to the authors, simply walking more could help maintain brain function well into old age.

This study^4,5,6,7 followed 324 female twins, aged 43 to 73, for a decade. Cognitive function such as learning and memory was tested at the outset and at the conclusion of the study. Interestingly, as reported by MedicineNet.com:⁸

"The researchers found that leg strength was a better predictor of brain health than any other lifestyle factor looked at in the study.

Generally, the twin with more leg strength at the start of the study maintained her mental abilities better and had fewer age-related brain changes than the twin with weaker legs...

'It's compelling to see such differences in cognition [thinking] and brain structure in identical twins, who had different leg power 10 years before,' [lead author Claire] Steves add 

'It suggests that simple lifestyle changes to boost our physical activity may help to keep us both mentally and physically healthy.'"

Previous research has demonstrated that exercise promotes brain health by releasing hormones from the muscles, which encourage the growth of new brain cells — a process known as neurogenesis or neuroplasticity.

Your brain's hippocampus, i.e. your memory center, is particularly adaptable and capable of growing new cells throughout your entire lifetime, even into your 90s, provided your lifestyle supports it.

For example, one year-long study found that adults who exercised regularly were actually enlarging their brain's memory center by one to two percent per year, where typically that center shrinks with age.

The study on twins is said to be the first showing a specific link between leg power and cognition in normal, healthy people, and this is great news, as your leg muscles are among the largest in your body and can be easily worked, either through seated leg exercises, or by standing and walking.

Exercise Boosts Brain Performance Among Students and Employees

The hippocampus belongs to the ancient part of your brain known as the limbic system, and plays an important role in the consolidation of information from your short-term memory to your long-term memory, as well as spatial navigation. Previous animal research⁹ has found that not only does exercise activate hippocampal neurons, it actually promotes their growth. In one study,¹⁰ exercising mice grew an average of 6,000 new brain cells in every cubic millimeter of tissue sampled.

The growth occurred in the hippocampus, the memory center of the brain, and the mice showed significant improvements in the ability to recall memories without any confusion.  A number of other studies have investigated the impact of exercise on brain performance and IQ. Some of the research highlights¹¹ include:

• Among elementary school students, 40 minutes of daily exercise increased IQ by an average of nearly four points
• Among sixth graders, the fittest students scored 30 percent higher than average students, and the less fit students scored 20 percent lower
• Among older students, those who play vigorous sports have a 20 percent improvement in Math, Science, English, and Social Studies
• Students who exercised before class improved test scores 17 percent, and those who worked out for 40 minutes improved an entire letter grade
• Employees who exercise regularly are 15 percent more efficient than those who do not, which means a fit employee only needs to work 42.5 hours in a week to do the same work as an average employee does in 50

To Optimize Your Health and Longevity, Stay in Constant Motion

The type of exercise program that will benefit your brain is identical to the one that will benefit the rest of your body. Ideally, you'd want to strive for a comprehensive routine that includes high-intensity interval exercise (HIIT), strength training, core work, and stretching. Then, in addition to a well-rounded workout routine, I also recommend standing up as much as possible to avoid the well-documented hazards associated with chronic sitting, and walking 7,000 to 10,000 steps a day.

Daily walking has been found to trigger an anti-aging process, and recent research suggests it may add anywhere from three to seven years to your lifespan. It's clearly an essential movement we all require, ideally in addition to a regular exercise program. And, once you've eased into a daily walk routine, you can easily turn it into a high-intensity walking workout, which may be especially beneficial if you're elderly or unable to engage in other forms of high-intensity exercises.

Best of all, you can benefit from walking no matter what age you get started. Study author Sanjay Sharma, professor of Inherited Cardiac Diseases in Sports Cardiology at St. George's University Hospitals NHS Foundation Trust in London, told The Independent:¹²

"We may never avoid becoming completely old, but we may delay the time we become old. We may look younger when we're 70 and may live into our nineties. Exercise buys you three to seven additional years of life. It is an antidepressant, it improves cognitive function, and there is now evidence that it may retard the onset of dementia."

Everyone Can Benefit from More Walking

Part of what makes walking so beneficial is that when you're walking you can't be sitting. Sitting for more than eight hours a day is associated with a 90 percent increased risk of type 2 diabetes, along with increased risks of heart disease, cancer, and all-cause mortality.¹³ I personally walk about two hours a day; about 60 miles per week.

I do this barefoot without a shirt on at the beach — this way I'm able to get my sun exposure at the same time, which is an added benefit. I also like to read while I walk and this allows me to read two or three books a week. Multi-tasking like this allows me to easily justify the time investment and reap the many benefits that daily walking offers. I have been doing this now for more than a year and have logged 3,000 miles, which is the distance of walking across the US.

Consider High Intensity Exercises for Maximum Health Boost

In addition to these daily walks, I also do some form of regimented exercise each day. This includes strength training four times a week. My current goal is to deadlift 400 pounds. Got up to 340 but have a ways to go. I also do a daily 30 minute stretching routine on the Power Plate.  

HIIT, which is a core component of my Peak Fitness program, maximizes your human growth hormone (HGH) secretion, optimizes your metabolism, and helps regulate your insulin and blood sugar. And nothing beats it in terms of efficiency. You can complete an entire Peak Fitness workout in 20 minutes or less.

My previous article, "Peak Fitness: Reap the Benefits of High-Intensity Interval Training," details the benefits of HIIT and offers guidance, instructions, and demonstrations for how to perform HIIT with or without equipment.

Strength Training Becomes Increasingly Important with Age

Getting back to strength training and working your muscles is important not just for its brain-boosting effects. It produces a number of molecular, enzymatic, hormonal, and chemical changes that help slow down and even reverse a number of diseases, including type 2 diabetes, osteoporosis, and heart disease. And, contrary to popular belief, strength training is particularly important for the elderly.

By strengthening muscles, connective tissues, tendons, and ligaments, strength training helps you maintain a stable body position, and allows you to perform everyday activities like climbing stairs and getting out of a chair with greater ease. This freedom of movement adds to your quality of life, but the benefits don't end there. One study showed that strength training in the elderly genetically turned back the biological clock about 10 years!

So where do you start?

If you're elderly and have been sedentary for some time, I suggest you begin by taking a look at my "Basic Exercise Guide for Older Seniors and the Infirm". It contains basic seated and standing exercises that can help improve balance and coordination. My article "Easy Strength Training Moves for Seniors" contain beginner's level strength training exercises, which you can then move into.

For the rest of you, I suggest reviewing my "Beginners Guide to Strength Training," which lists a number of strength training options, such as body weight exercises, kettle bells, resistance bands, medicine balls, resistance machines, and more.

How to Get the Most out of Your Strength Training Routine

Last but not least, you can also turn your strength training routine into a high-intensity exercise. This is done by slowing down your movements. Super-slow weight training is a particularly well-suited form of high-intensity exercise for older individuals, as it actively prevents you from accidentally harming your joints or suffering repetitive use injury.

In the video below I discuss and demonstrate the proper execution of a number of different super-slow weight training exercises. They can all be done using either free weights or machines. The benefit of using a quality machine is that it will allow you to focus your mind on the effort, as opposed to the movement.

The typical super-slow resistance workout can be completed in about 15 minutes. Just one or two of these workouts are needed each week, as you need to make sure you've sufficiently recovered between sessions.