Can exercise make us smarter?
We hear so much about the physical benefits of regular exercise. But what effects do exercise and staying fit have on our cognitive function? Research has looked at how well people perform mentally, both while exercising and immediately after an exercise session. Other research has examined the association between fitness level and age-related cognitive decline.
Unlike physical measurements that can be taken with some precision, defining tests of mental performance and exercise to get reliable outcomes is a much greater challenge. Despite the obstacles, researchers have made some headway.
Mental performance tasks influenced by exercise
During a session of moderately intense aerobic exercise, mental performance improves in several measurable ways:
perception and interpretation of visual images
executive control processes
Of these, exercise exerts the most positive influence on tasks of executive control, such as:
coordination of people, places, events, etc.
working memory—the brain’s ability to temporarily store and manage the information required to carry out complex mental functions
inhibition—the ability to block out unnecessary distractions
How long does improvement take?
Improved cognitive function begins to show at about 20 minutes of moderate intensity aerobic exercise and will be maintained for about another 40 minutes. Beyond 60 minutes of exercise, fatigue is likely to become a factor. For very fit individuals, enhanced mental performance could continue beyond an hour.
Once fatigue sets in, you start to lose the mental edge you have gained. If exercise continues, then mental performance actually will decline to a level lower than where you started.
These positive cognitive effects of exercising for 20 to 60 minutes are primarily related to increase in blood flow to the brain and stimulation of nerve cells to release more neurotransmitters (chemicals that send signals between brain cells). These positive effects will be maintained for a short time after the exercise session as long as you have not become overly fatigued. If you expect to have a long and hard workout, don’t plan on doing any important decision making or complex mental functions immediately afterward.
Influence of exercise intensity
Moderate intensity aerobic exercise that keeps you breathing a little faster and makes you sweat is probably the optimal intensity level to get the mental boost. If you monitor your heart rate to guide your intensity level, you want to strive for about 75% of your maximal heart rate.
With moderate intensity exercise, your body is activating the sympathetic nervous system and raising levels of adrenalin. These are likely the two main factors driving improvements in mental performance.
At high intensity of exercise, you will perceive your level of exertion and this sensation will likely interfere with concentration and ability to perform mental tasks.
Fluid intake and exercise
Dehydration is associated with a marked reduction in mental performance, independent of whether it is exercise-induced or caused by other factors. Researchers have shown that the decreased cognitive function immediately after exercise-induced dehydration can be quickly reversed once fluids are given to return body weight to the pre-exercise level.
One study found that hyper-hydration, extra fluid beyond what is lost, improved mental performance more than just replacing fluid losses. This principle should not be taken to extreme since over-hydration with water during prolonged exercise can dangerously lower blood levels of sodium (a condition called hyponatremia).
Water and sports drinks are equally effective at maintaining hydration during exercise. Sports drinks that contain simple carbohydrates (sugar) may provide a mental advantage for other reasons.
Carbohydrates to feed the brain
The brain needs a constant supply of glucose to function normally. During exercise, the body preferentially uses glucose as the main energy source for contracting muscles, including the heart and the muscles used to expand the lungs. At moderate intensity exercise of 20 to 60 minutes, there is still plenty of sugar available to the brain to allow the improved mental performance noted above. If exercise is more prolonged, especially at a high intensity level, then the amount of blood sugar available to the brain may be an issue.
Studies have shown that cognitive function is better when fluids are replaced with a sugar-containing solution rather than a drink without any calories. However, when blood glucose levels are measured, they are not low enough to say that hypoglycemia is the explanation. More likely, the sugar-containing solutions improve endurance and lessen the perceived level of exertion. Improving both of these factors positively impacts mental performance.
Boosting cognition now and for the future
In the short run, each session of aerobic exercise on a stable piece of equipment such as a stationary bike, treadmill, or elliptical machine has the potential to give you a double benefit for your time spent. Not only will you be improving your fitness, your ability to concentrate on and perform mental tasks also will likely be enhanced.
In the long run, physical activity appears to be at least as important in staying mentally sharp as keeping your mind active and maintaining strong social connections. Multiple studies have shown that people who exercise regularly will have less age-related cognitive decline and lose less brain tissue, as seen on MRI and PET scans.
Here are five tips to create a healthful diet that you can enjoy.
Learn to think about food in a new way. Years ago, meat and potatoes were the American ideal. Now we know that vegetables, fruits, whole grains, nuts, and fish are best.
Experiment with new recipes and meal plans. Be creative and take chances. Instead of dreading your new diet, have fun with it.
Change slowly. By the time you are 40, you’ll have eaten some 40,000 meals—and lots of snacks besides. Give yourself time to change, targeting one item a week.
Start with breakfast, switching from eggs, bacon, donuts, white toast, or bagels to oatmeal or bran cereal and fruit. If you just can’t spare 10 minutes for a sit-down breakfast, grab high-fiber cereal bars instead of donuts or muffins.
Next, try out salads, low-fat yogurt or low-fat cottage cheese, tuna or peanut butter sandwiches, and fruit for lunch.
Snack on unsalted nuts, trail mix, fruit, raw veggies, Rye Krisp, or graham crackers. Try eating a few handfuls of a crunchy fiber cereal such as Kashi, or nibble on a cereal bar.
For dinner, experiment with fish, skinless poultry, beans, brown rice, whole-wheat pasta, and, of course, salads and veggies.
Fruit and low-fat frozen desserts are examples of desirable after-dinner treats. And there’s nothing wrong with the occasional cake, pie, or chocolates as long as the portions are moderate.
Be relaxed about your diet. You will never find a perfect food. Not everything on your plate needs to have a higher purpose. Take your tastes and preferences into account. If roast beef is your favorite food, it is okay to eat it—but try to make it a Sunday treat instead of a daily staple. The choices are your—and the better your overall diet, the more “wiggle room” you’ll have to indulge your passions.
Take a long-range view. Don’t get down on yourself if you slip up or “cheat” from time to time. Don’t worry about every meal, much less every mouthful. Your nutritional peaks and valleys will balance out if your overall dietary pattern is sound.
You aren’t thinking about yourself. You aren’t focused on your comfort, and you aren’t wondering how you look or how your actions will be perceived by others. Your awareness of yourself is only in relation to the activity itself, such as your fingers on a piano keyboard, or the way you position a knife to cut vegetables, or the balance of your body parts as you ski or surf.
Memory gets most of the attention, but executive function is another part of thinking affected by aging.
Most of us realize that our brains aren’t miraculously immune from the aging process. Along with creakier knees and thinner hair, we expect some forgetfulness. More often than not, forgotten names and other lapses can be ascribed to normal age-related memory loss (subtext: “don’t worry, it’s not Alzheimer’s disease.”) And there are some tried-and-true ways to compensate for these mental glitches (more on that below).
We worry a lot about memory loss and, understandably, it gets a lot of attention from doctors and researchers. But age-related changes in our brains also affect other cognitive processes. One of the most important is executive function, an umbrella term for the complex thinking required to make choices, plan, initiate action, and inhibit impulses. Executive function affects everything from walking speed and attention spans to friendships and family ties (as some inhibition is necessary for socially appropriate behavior). Not surprisingly, studies have shown that executive function is more important than many kinds of memory for managing the day-to-day tasks of independent living. In addition, diminished executive function in older people seems to be associated with a higher risk for falling, and a fall is often a calamitous event for an older person, ushering in ill health and disability.
Compared with all that has been written about memory, the advice on preventing and coping with the loss of executive function is pretty short. Children with attention deficit hyperactivity disorder (ADHD) have poor executive function, and researchers have studied whether methylphenidate (Ritalin, Concerta), the drug that’s most commonly used to treat ADHD, might help older people with executive function deficits. The results have been mixed, so pharmacology may have some answers, but it doesn’t look like it will produce a quick fix. (If you are interested in these studies, we’ve put some of the details on our Web site at www.harvard.health.edu/healthextra; look for the March 2010 issue.)
The good, if not terribly exciting, news is that the dos and don’ts of preserving executive function include many of the common precepts for staying healthy. For example, the to-do list once again includes exercise, as the evidence that older minds benefit from busier bodies continues to grow. A number of randomized controlled trials have shown that older people who exercise have better executive function than those who remain idle, and aerobic exercise (the kind that gets your heart going) may be especially beneficial. Results from a small study (33 people) published in Archives of Neurology in January 2010 showed that a fairly intense aerobic exercise program (four 45- to 60-minute sessions per week) improved the executive function of women with mild cognitive impairment. (The men weren’t so fortunate.)
That familiar nemesis, high blood pressure, affects both memory and executive function, but it seems to have a more pronounced effect on the latter. The road to blood pressure control is well-marked, if sometimes difficult to travel: lose weight, eat more fruit and vegetables, cut back on sodium. People often end up taking a blood pressure–lowering medication.
Lack of sleep scrambles many cognitive functions, including executive function, so you can probably add maintenance of executive functioning to the long list of reasons for getting good sleep regularly.
The boss of our thoughts
Executive function has been compared to the conductor of a symphony orchestra. The term represents the brain’s system for organizing and integrating other cognitive processes the way a conductor gets musicians to play together. That’s an imperfect analogy (most are), and comparisons to other authority figures — a boss, a coach, a director — might work just as well. The underlying notion is the same regardless. Executive function can be viewed as the higher-order tasks that impose some order on our unruly mental lives — the thoughts that keep the cognitive underlings in line.
When it comes to actually defining executive function, every researcher and textbook seems to do it a bit differently, but the ability to plan is almost always mentioned. Planning requires a whole set of interlocking cognitive tasks. You have to set a goal, direct attention to the task at hand while ignoring others, modulate behaviors so constructive action can take place, and control impulses that would otherwise get in the way of those constructive behaviors — and that’s just a partial list. Poor executive functioning may result from a deficit in any one of these areas. And while it’s useful for some purposes to tease memory and executive function apart, there’s also considerable overlap between them. It’s clear, for example, that some working memory — holding information “on line” for a short time — is necessary for us to plan. Memory and the ability to envision future events, a component of planning, are related. Results of a study published in 2009 showed that people with Alzheimer’s have trouble imagining future events, in addition to remembering past ones.
Some authors argue that executive function is an evolutionary advantage that allows higher organisms — particularly human beings — to take in new information, consider it, and choose from several available options, rather than depending on innate drives and reflexes. Another way to put it is that executive function allows us to decide rather than just react.
Researchers believe the area of the brain most involved in executive function is the prefrontal cortex, which, as the name suggests, is in the forefront of the brain. The prefrontal cortex includes the anterior cingulate gyrus, which has been associated with attention and response to stimulation, and the ventral prefrontal cortex, which has been associated with inhibition and social appropriateness. However, mapping executive function to only certain areas of the brain oversimplifies matters, because a complicated process like executive function depends on a network of connections to many other parts of the brain. Moreover, brain anatomy and function aren’t hard-wired. If one part of the brain isn’t functioning properly, another part can take over.
Dementia and executive function
Dementia is a word that gets tossed around a lot. It’s often equated with Alzheimer’s disease, when, in fact, there are several disorders (Lewy body disease, frontotemporal lobar degeneration) that harm brain tissue differently than Alzheimer’s does but also result in dementia. Moreover, many cases of dementia are vascular in origin: small areas of the brain die, are damaged, or don’t function properly because of inadequate blood flow from damaged or blocked blood vessels. To further complicate matters, the various causes of dementia often overlap, so, for example, people may have dementia from a mixture of Alzheimer’s disease and vascular deficits.
When dementia is being used to describe a state of mind and not the disease that is causing it, the term is sometimes used interchangeably for memory impairment. But that’s an oversimplification. According to the strict psychiatric definition, memory impairment is just one element, and a diagnosis of dementia requires memory impairment and at least one other cognitive “disturbance”: aphasia (impaired ability to use language), apraxia (impaired ability to perform simple movements despite having intact motor abilities), agnosia (failure to recognize familiar objects), or poor executive function.
In this definition, the memory impairment part of dementia affects the ability to learn new information, to recall previously “stored” information, or both. Executive function is said to require abstract thinking and to entail the ability to plan, initiate, and sequence behavior. So it’s easy to see how memory impairment would make good executive functioning very difficult, if not impossible. If you can’t gather or hold on to information, it’s hard to make a plan and maybe even harder to follow through on it.
Executive function isn’t a new concept, but researchers are beginning to make a point of considering it separately as they design studies and analyze data. This is particularly true for investigations into aging and cognitive function. Two examples published in 2009 were based on data collected for MOBILIZE Boston, a study of the risk factors for mobility and falls in older people (average age 78) that is funded by the National Institute on Aging and based at Hebrew SeniorLife, a Harvard-affiliated long-term care provider in Boston.
The first study compared people’s physical activity levels, as measured by a standardized questionnaire, with their scores on a battery of tests designed to measure different aspects of thinking. Statistical adjustments were made for age, sex, education, and cardiovascular disease. Right in line with results from other studies, the researchers found that people who were more active were also more likely to have well-preserved executive function. But when they looked at the tests for memory, they didn’t find a correlation between high scores and physical activity. Their tentative conclusion: physical activity has a specific biological benefit for executive function that it might not have for memory.
The second study used a statistical technique called latent class analysis that groups people into clusters based on whether they share some predetermined attributes. In this case, the researchers — most of whom are affiliated with Harvard — examined the results of brief tests that measure memory, executive function, walking speed, and depression. After crunching the numbers for about 580 participants in the MOBILIZE Boston study, they identified a cluster of 99 — about one in six people in the analysis — who shared three attributes: a very slow gait, depression, and poor executive function. Notably, memory deficits were not included. When the researchers dug a little further, they found that some of the classic cardiovascular risk factors — high blood pressure, diabetes — were associated with being a member of this low-performing group. They speculated that the triad of slow gait, depression, and poor executive function is a manifestation of a brain suffering from “vascular aging” — the slow accumulation of minor damage to the small arteries that supply the brain. Moreover, this vascular aging may have a specific effect on the part of the brain that controls executive function. This is the flip side to the first research group’s inference that physical activity might have special benefits for executive function.
Ways to improve your executive function
We’ve already mentioned the research that suggests that exercise, blood pressure, and sleep seem to have an effect on our inner CEOs. Avoiding excess stress and alcohol could probably be added to the list. These are generic, all-purpose risk factors, invoked over and over again, partly because doing so plays into the belief that we, as individuals, have some power to change them.
But is there anything more specific we can do for executive function? After all, millions of words have been written and spoken about techniques for preserving and improving memory. The standard advice includes building associations between new information and older memories and chunking information. We’ve posted descriptions of some of these techniques on our Web site.
In contrast, precious little has been said about keeping our executive functioning sharp. However, some of the common suggestions for memory preservation and enhancement are very much related to executive function and its various components. Here are a few examples:
Pay attention to paying attention. A common memory tip is to work on maintaining focus, because as we age, new information doesn’t seem to get “into” our memories as easily as it did when we were young and our brains spongier. Attention is a central part of executive function, so this memory advice is, in effect, asking us to dial up our executive functioning.
Say it out loud. Saying things out loud is another standard memory tip (“I am now putting my keys in my pocket”). Doing so encourages a person to pause and pay attention to what he or she is doing.
Make it a habit. Memory books typically suggest putting keys and other personal items in the same place so you don’t have to remember where you put them. That suggestion, plus others to reduce clutter and work on organizational systems, can be seen as ways of reducing demands on executive functioning. If the keys are always in the same place, we know automatically where they are and don’t have to get executive functioning involved to find them.
Write it down. Lists and plans of action are a way of “outsourcing” executive function from the brain to a piece of paper or a computer file. We may need executive function to create these lists, but having them recorded elsewhere allows us to go on autopilot a little bit, instead of redeciding everything over and over again.
Many people don’t realize that lack of sufficient sleep can trigger mild to potentially life-threatening consequences, from weight gain to a heart attack.
Anecdotal evidence supports the notion that when you’re tired and run-down, you’re more likely to get sick. A 2009 study in Archives of Internal Medicine offers some proof. Researchers tracked the sleep habits of 153 men and women for two weeks, then quarantined them for five days and exposed them to cold viruses. People who slept an average of less than seven hours per night were three times as likely to get sick as those who averaged at least eight hours.
Not getting enough sleep makes you more likely to gain weight, according to a 2008 review article in the journal Obesity that analyzed findings from 36 different studies of sleep duration and body weight.
The link appears to be especially strong among children. Lack of sufficient sleep tends to disrupt hormones that control hunger and appetite, and the resulting daytime fatigue often discourages you from exercising. Excess weight, in turn, increases the risk of a number of health problems—including some of those listed in the following paragraphs.
A 2009 report in Diabetes Care found a sharp increase in the risk of type 2 diabetes in people with persistent insomnia. People who had insomnia for a year or longer and who slept less than five hours per night had a threefold higher risk of type 2 diabetes compared with those who had no sleep complaints and who slept six or more hours nightly. As with overweight and obesity (which are also closely linked to type 2 diabetes), the underlying cause is thought to involve a disruption of the body’s normal hormonal regulation resulting from insufficient sleep.
Researchers involved in the diabetes study also evaluated risk of high blood pressure among the same group of people, which included more than 1,700 randomly chosen men and women from rural Pennsylvania.
As described in a 2009 article in the journal Sleep, the researchers found the risk of high blood pressure was three-and-a-half times greater among insomniacs who routinely slept less than six hours per night compared with normal sleepers who slept six or more hours nightly.
A number of studies have linked short-term sleep deprivation with several well-known risk factors for heart disease, including higher cholesterol levels, higher triglyceride levels, and higher blood pressure.
One such report, published in a 2009 issue of Sleep, included more than 98,000 Japanese men and women ages 40 to 79 who were followed for just over 14 years. Compared with women who snoozed for seven hours, women who got no more than four hours of shut-eye were twice as likely to die from heart disease, the researchers found.
One common cause of poor sleep, sleep apnea—a life-threatening condition in which breathing stops or becomes shallower hundreds of times each night—also raises heart disease risk. In the Wisconsin Sleep Cohort study, people with severe sleep apnea were three times more likely to die of heart disease during 18 years of follow-up than those without apnea. When researchers excluded those who used a breathing machine (a common apnea treatment), the risk jumped to more than five times higher. Apnea spells can trigger arrhythmias (irregular heartbeats), and the condition also increases the risk of stroke and heart failure.
A study of about 1,000 adults ages 21 to 30 found that, compared with normal sleepers, those who reported a history of insomnia during an interview were four times as likely to develop major depression by the time of a second interview three years later. And two studies in young people—one involving 300 pairs of young twins, and another including about 1,000 teenagers—found that sleep problems developed before a diagnosis of major depression and (to a lesser extent) anxiety. Sleep problems in the teenagers preceded depression 69% of the time and anxiety disorders 27% of the time.
In the Japanese heart disease study described above, short sleepers of both genders had a 1.3-fold increase in mortality compared with those who got sufficient sleep. Severe sleep apnea raises the risk of dying early by 46%, according to a 2009 study of 6,400 men and women whom researchers followed for an average of eight years. Although only about 8% of the men in the study had severe apnea, those who did and who were between 40 and 70 years of age were twice as likely to die from any cause as healthy men in the same age group.
Maybe you’ve gone into the kitchen and can’t remember why, or can’t recall a familiar name during a conversation. You may even miss an appointment because it slipped your mind. Memory lapses can occur at any age, but we tend to get more upset by them as we get older because we fear they’re a sign of dementia, or loss of intellectual function. The fact is, significant memory loss in older people isn’t a normal part of aging—but is due to organic disorders, brain injury, or neurological illness, with Alzheimer’s being among the most feared.
Most of the fleeting memory problems that we experience with age reflect normal changes in the structure and function of the brain. These changes can slow certain cognitive processes, making it a bit harder to learn new things quickly or screen out distractions that can interfere with memory and learning. Granted, these changes can be frustrating and may seem far from benign when we need to learn new skills or juggle myriad responsibilities. Thanks to decades of research, there are various strategies we can use to protect and sharpen our minds. Here are seven you might try.
A higher level of education is associated with better mental functioning in old age. Experts think that advanced education may help keep memory strong by getting a person into the habit of being mentally active. Challenging your brain with mental exercise is believed to activate processes that help maintain individual brain cells and stimulate communication among them. Many people have jobs that keep them mentally active, but pursuing a hobby or learning a new skill can function the same way. Read; join a book group; play chess or bridge; write your life story; do crossword or jigsaw puzzles; take a class; pursue music or art; design a new garden layout. At work, propose or volunteer for a project that involves a skill you don’t usually use. Building and preserving brain connections is an ongoing process, so make lifelong learning a priority.
2. Use all your senses
The more senses you use in learning something, the more of your brain will be involved in retaining the memory. In one study, adults were shown a series of emotionally neutral images, each presented along with a smell. They were not asked to remember what they saw. Later, they were shown a set of images, this time without odors, and asked to indicate which they’d seen before. They had excellent recall for all odor-paired pictures, and especially for those associated with pleasant smells. Brain imaging indicated that the piriform cortex, the main odor-processing region of the brain, became active when people saw objects originally paired with odors, even though the smells were no longer present and the subjects hadn’t tried to remember them. So challenge all your senses as you venture into the unfamiliar. For example, try to guess the ingredients as you smell and taste a new restaurant dish. Give sculpting or ceramics a try, noticing the feel and smell of the materials you’re using.
Myths about aging can contribute to a failing memory. Middle-aged and older learners do worse on memory tasks when they’re exposed to negative stereotypes about aging and memory, and better when the messages are positive about memory preservation into old age. People who believe that they are not in control of their memory function are less likely to work at maintaining or improving their memory skills and therefore are more likely to experience cognitive decline. If you believe you can improve and you translate that belief into practice, you have a better chance of keeping your mind sharp.
If you don’t need to use mental energy remembering where you laid your keys or the time of your granddaughter’s birthday party, you’ll be better able to concentrate on learning and remembering new and important things. Take advantage of calendars and planners, maps, shopping lists, file folders, and address books to keep routine information accessible. Designate a place at home for your glasses, purse, keys, and other items you use often. Remove clutter from your office or home to minimize distractions, so you can focus on new information that you want to remember.
When you want to remember something you’ve just heard, read, or thought about, repeat it out loud or write it down. That way, you reinforce the memory or connection. For example, if you’ve just been told someone’s name, use it when you speak with him or her: “So, John, where did you meet Camille?” If you place one of your belongings somewhere other than its usual spot, tell yourself out loud what you’ve done. And don’t hesitate to ask for information to be repeated.
Repetition is most potent as a learning tool when it’s properly timed. It’s best not to repeat something many times in a short period, as if you were cramming for an exam. Instead, re-study the essentials after increasingly longer periods of time — once an hour, then every few hours, then every day. Spacing out periods of study is particularly valuable when you are trying to master complicated information, such as the details of a new work assignment. Research shows that spaced rehearsal improves recall not only in healthy people but also in those with certain physically based cognitive problems, such as those associated with multiple sclerosis.
7. Make a mnemonic
This is a creative way to remember lists. Mnemonic devices can take the form of acronyms (such as RICE to remember first-aid advice for injured limbs: Rest, Ice, Compression, and Elevation) or sentences (such as the classic “Every good boy does fine” to remember the musical notes E, G, B, D, and F on the lines of the treble clef).
Change is an important part of living with heart disease or trying to prevent it. A jump in blood pressure or cholesterol earns you a lecture on healthy lifestyle changes. Heart attack and stroke survivors are often told to alter a lifetime of habits.
Some people manage to overhaul their exercise pattern, diet, and unhealthy habits with ease. The rest of us try to make changes, but don’t always succeed. Instead of undertaking a huge makeover, you might be able to improve your heart’s health with a series of small changes. Once you get going, you may find that change isn’t so hard. This approach may take longer, but it could also motivate you to make some big changes.
Here are 10 small steps to get you on the road to better health in 2010.
1. Take a 10-minute walk. If you don’t exercise at all, a brief walk is a great way to start. If you do, it’s a good way to add more exercise to your day.
2. Give yourself a lift. Lifting a hardcover book or a two-pound weight a few times a day can help tone your arm muscles. When that becomes a breeze, move on to heavier items or join a gym.
3. Eat one extra fruit or vegetable a day. Fruits and vegetables are inexpensive, taste good, and are good for everything from your brain to your bowels.
4. Make breakfast count. Start the day with some fruit and a serving of whole grains, like oatmeal, bran flakes, or whole-wheat toast.
5. Stop drinking your calories. Cutting out just one sugar-sweetened soda or calorie-laden latte can easily save you 100 or more calories a day. Over a year, that can translate into a 10-pound weight loss.
6. Have a handful of nuts. Walnuts, almonds, peanuts, and other nuts are good for your heart. Try grabbing some instead of chips or cookies when you need a snack, adding them to salads for a healthful and tasty crunch, or using them in place of meat in pasta and other dishes.
7. Sample the fruits of the sea. Eat fish or other types of seafood instead of red meat once a week. It’s good for the heart, the brain, and the waistline.
8. Breathe deeply. Try breathing slowly and deeply for a few minutes a day. It can help you relax. Slow, deep breathing may also help lower blood pressure.
9. Wash your hands often. Scrubbing up with soap and water often during the day is a great way to protect your heart and health. The flu, pneumonia, and other infections can be very hard on the heart.
10. Count your blessings. Taking a moment each day to acknowledge the blessings in your life is one way to start tapping into other positive emotions. These have been linked with better health, longer life, and greater well-being, just as their opposites — chronic anger, worry, and hostility — contribute to high blood pressure and heart disease.
Whether you’re 9 or 90, abundant evidence shows exercise can enhance your health and well-being. But for many people, sedentary pastimes, such as watching TV, surfing the Internet, or playing computer and video games, have replaced more active pursuits.
What exercise can do for you
Millions of Americans simply aren’t moving enough to meet the minimum threshold for good health — that is, burning at least 700 to 1,000 calories a week through physical pursuits. The benefits of exercise may sound too good to be true, but decades of solid science confirm that exercise improves health and can extend your life. Adding as little as half an hour of moderately intense physical activity to your day can help you avoid a host of serious ailments, including heart disease, diabetes, depression, and several types of cancer, particularly breast and colon cancers. Regular exercise can also help you sleep better, reduce stress, control your weight, brighten your mood, sharpen your mental functioning, and improve your sex life.
A well-rounded exercise program has four components: aerobic activity, strength training, flexibility training, and balance exercises. Each benefits your body in a different way.
Fighting disease with aerobic activity
Aerobic exercise is the centerpiece of any fitness program. Nearly all of the research regarding the disease-fighting benefits of exercise revolves around cardiovascular activity, which includes walking, jogging, swimming, and cycling. Experts recommend working out at moderate intensity when you perform aerobic exercise—brisk walking that quickens your breathing is one example. This level of activity is safe for almost everyone and provides the desired health benefits. Additional health benefits may flow from increased intensity.
Protecting bone with strength training
Strength or resistance training, such as elastic-band workouts and the use of weight machines or free weights, are important for building muscle and protecting bone.
Bones lose calcium and weaken with age, but strength training can help slow or sometimes even reverse this trend. Not only can strength training make you look and feel better, but it can also result in better performance of everyday activities, such as climbing stairs and carrying bundles. Stronger muscles also mean better mobility and balance, and thus a lower risk of falling and injuring yourself. In addition, more lean body mass aids in weight control because each pound of muscle burns more calories than its equivalent in fat.
Ease back pain with flexibility exercises
Stretching or flexibility training is the third prong of a balanced exercise program. Muscles tend to shorten and weaken with age. Shorter, stiffer muscle fibers make you vulnerable to injuries, back pain, and stress. But regularly performing exercises that isolate and stretch the elastic fibers surrounding your muscles and tendons can counteract this process. And stretching improves your posture and balance.
Preventing falls with balance exercises
Balance tends to erode over time, and regularly performing balance exercises is one of the best ways to protect against falls that lead to temporary or permanent disability. Balance exercises take only a few minutes and often fit easily into the warm-up portion of a workout. Many strength-training exercises also serve as balance exercises. Or balance-enhancing movements may simply be woven into other forms of exercise, such as tai chi, yoga, and Pilates.
Exercise at a glance
In a nutshell, exercise can:
reduce your chances of getting heart disease. For those who already have heart disease, exercise reduces the chances of dying from it.
lower your risk of developing hypertension and diabetes.
reduce your risk for colon cancer and some other forms of cancer.
improve your mood and mental functioning.
keep your bones strong and joints healthy.
help you maintain a healthy weight.
help you maintain your independence well into your later years.