From WSJ.com:

As millions of Americans flock to the gym armed with New Year’s resolutions to get in shape, medical experts are offering an additional reason to exercise: Regular workouts may help fight off colds and flu, reduce the risk of certain cancers and chronic diseases and slow the process of aging.

Physical activity has long been known to bestow such benefits as helping to maintain a healthy weight and reduce stress, not to mention tightening those abs. Now, a growing body of research is showing that regular exercise—as simple as a brisk 30- to 45-minute walk five times a week—can boost the body’s immune system, increasing the circulation of natural killer cells that fight off viruses and bacteria. And exercise has been shown to improve the body’s response to the influenza vaccine, making it more effective at keeping the virus at bay.

“No pill or nutritional supplement has the power of near-daily moderate activity in lowering the number of sick days people take,” says David Nieman, director of Appalachian State University’s Human Performance Lab in Kannapolis, N.C. Dr. Nieman has conducted several randomized controlled studies showing that people who walked briskly for 45 minutes, five days a week over 12 to 15 weeks had fewer and less severe upper respiratory tract infections, such as colds and flu. These subjects reduced their number of sick days 25% to 50% compared with sedentary control subjects, he says.
[INFORMED]

Medical experts say inactivity poses as great a health risk as smoking, contributing to heart disease, diabetes, hypertension, cancer, depression, arthritis and osteoporosis. The Centers for Disease Control and Prevention says 36% of U.S. adults didn’t engage in any leisure-time physical activity in 2008.

Even lean men and women who are inactive are at higher risk of death and disease. So while reducing obesity is an important goal, “the better message would be to get everyone to walk 30 minutes a day” says Robert Sallis, co-director of sports medicine at Fontana Medical Center, a Southern California facility owned by managed-care giant Kaiser Permanente. “We need to refocus the national message on physical activity, which can have a bigger impact on health than losing weight.”

Regular exercise has been shown to combat the ongoing damage done to cells, tissues and organs that underlies many chronic conditions. Indeed, studies have found that exercise can lower blood pressure, reduce bad cholesterol, and cut the incidence of Type 2 diabetes.

Building on that earlier research, scientific studies are now suggesting that exercise-induced changes in the body’s immune system may protect against some forms of cancer. For example, Harvard Medical School’s consumer Web site (hms.harvard.edu/public/consumer) notes that more than 60 studies in recent years taken together suggest that women who exercise regularly can expect a 20% to 30% reduction in the chance of getting breast cancer compared with women who didn’t exercise. While researchers are still studying the molecular changes caused by exercise and how they affect cancer, the studies suggest the outcome could be due to exercise’s ability to lower estrogen levels.

One study of 3,000 women being treated for breast cancer, published in the Journal of the American Medical Association, showed that for those patients with hormone-responsive tumors, walking the equivalent of three to five hours per week at an average pace reduced the risk of dying from the disease by 50% compared with more sedentary women.

Researchers are also investigating whether exercise can influence aging in the body. In particular, they are looking at whether exercise lengthens telomeres, the strands of DNA at the tips of chromosomes. When telomeres get too short, cells no longer can divide and they become inactive, a process associated with aging, cancer and a higher risk of death.

In a study published in November in Circulation, the medical journal of the American Heart Association, German researchers compared two groups of professional athletes (32 of whom were in their early 20s, and 25 who were middle-aged) with two groups (26 young and 21 middle-aged) who were healthy nonsmokers, but not regular exercisers. The athletes had significantly less erosion in telomeres than their more sedentary counterparts. The study concluded that physical activity has an anti-aging effect at the cellular level, suggesting exercise could prevent aging of the cardiovascular system.

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Health Column

* Why You Should Step Up Your Workout

Wake-Up Call for Couch Potatoes

The federal government, which issued its first physical-activity guidelines for Americans in 2008, is developing a national plan to encourage their use. Here are recommendations for adults:

* At least two hours and 30 minutes a week of moderate-intensity, or one hour and 15 minutes a week of vigorous-intensity aerobic physical activity, or a combination of moderate and vigorous activity. Aerobic-activity episodes should last at least 10 minutes, preferably spread through the week.
* Additional health benefits are gained from as much as doubling the minimum recommended time spent each week in moderate or vigorous aerobic physical activity.
* Muscle-strengthening activities for all major muscle groups two or more days a week.
* Moderate activity can include ballroom and line dancing; biking on level ground or with a few hills; canoeing; gardening (raking, trimming shrubs); tennis (doubles); brisk walking; water aerobics.
* Among vigorous-activity exercises are aerobic dance; biking faster than 10 miles an hour; heavy gardening (digging, hoeing); tennis (singles); jumping rope; swimming laps; hiking uphill; race walking, jogging or running.

– U.S. Dept. of Health and Human Services

Efforts are underway to get sedentary Americans moving. The federal government issued its first national exercise guidelines in 2008. Now it is working with a number of medical and fitness groups to develop a National Physical Activity plan, to be released early this year, to encourage Americans to adhere to the guidelines.

The guidelines, developed by the Department of Health and Human Services and available online at health.gov/paguidelines, recommend that adults get at least two hours and 30 minutes weekly of moderate-intensity aerobic physical activity, or one hour and 15 minutes a week of vigorous-intensity aerobic exercise, or an equivalent combination of both. The guidelines also say that additional health benefits can be had from as much as doubling the minimum recommendation for aerobic exercise. Also recommended: muscle-strengthening activities two or more days per week, which protects against a decline in bone mass, especially that experienced by post-menopausal women.

Kaiser Permanente’s Dr. Sallis also is chairman of Exercise is Medicine, a two-year-old program developed by the American College of Sports Medicine and the American Medical Association to encourage doctors to assess and review each patient’s physical activity program at every visit. A survey by the ACSM, whose members include physicians and exercise-science professionals, found that only four out of 10 doctors talk to their patients about the importance of exercise, and they don’t always offer suggestions on the best ways to be physically active.

Kaiser Permanente’s California facilities last year began rolling out exercise counseling to eight million members as part of their regular doctor visits. The company also has set up a toll-free telephone line to help members create a personal-fitness plan incorporating favorite activities like gardening. “Exercise can be used like a vaccine to prevent disease and a medication to treat disease,” says Dr. Sallis. “If there were a drug with the same benefits as exercise, it would instantly be the standard of care.”

While some patients may have risk factors such as heart conditions that could lead to heart attacks and sudden cardiac death with physical exertion, physicians can screen for such risks before prescribing an exercise program. Also, the exerciseismedicine.org Web site includes videos and self-assessment tools for consumers on how to start an exercise program, including how to exercise with diseases such as asthma and heart disease, and exercise following a stroke or heart attack.

Starting an exercise program can have benefits at any age, but is particularly important for those over 40, when physical strength, endurance, flexibility and balance begin to decline, says Pamela Peeke, a Bethesda, Md., physician and fitness expert who is the author of “Fit to Live,” an advice book on how to create and stick to a fitness plan.

Naomi Henderson, 66, says Dr. Peeke gave her an exercise prescription several years ago, when she weighed 220 pounds. The plan called for Ms. Henderson, who owns her own market-research company, to start by walking on a treadmill five minutes a day and gradually increase the duration as her fitness level improved. Eventually she was able to walk in a marathon. Ms. Henderson says she has slimmed down to a size 12 from an 18 and says she is rarely ill. “I look at exercise as no different than a drug I have to take to stay healthy,” she says.

Lisa Callahan, co-director of the Women’s Sports Medicine Center at New York’s Hospital for Special Surgery, says her patients are often only partially aware of the benefits of exercise.

They may know that it is helpful in reducing their risk of osteoporosis, for example, but they usually don’t know that a combination of strength training, aerobic exercise and balance training is most effective at staving off the disease, says Dr. Callahan, who is the author of “The Fitness Factor,” a guide for women.

Dr. Nieman, of Appalachian State University, says that during exercise, two types of immune cells circulate more freely in the blood, neutralizing pathogens. Although the immune system returns to normal within three hours, the effect of the exercise is cumulative, adding up over time to reduce illness rates, he says. He compares the process to “a cleaner who comes in for an hour a day, so by the end of a month, your house looks much better.”

But, Dr. Nieman says, high-intensity exercise over long periods, like running a marathon, can “take a good thing too far.” Such exertion can induce the release of stress hormones in the body that damp some functions of the immune system temporarily, increasing susceptibility to infection for short periods. He cites a five-year study he conducted on 350 athletes who completed an ultra-marathon 160-kilometer race in the Sierra Nevada mountains. Among the contestants, one out of four reported sickness in the two weeks following the races.

Still, says Robert Mazzeo, a professor in the department of integrative physiology at the University of Colorado in Boulder, although a single bout of intense exercise can suppress the immune system, long-term training in marathoners and other athletes can boost their baseline immunity and ability to respond to the stress of intense exercising.

Rather than worrying about super athletes, however, “my concern is the sedentary people who start out pumping the Stairmaster too hard, then get sick and stop working out,” says Dr. Mazzeo. “If you’ve made a New Year’s resolution to get in shape, don’t try to do it all at once,” he says.

From Forbes.com:

One day in the summer of 2001, Dan Radin decided to run to the end of his block. For many, that short distance might be conquered in a minute or two. But Radin, a 21-year-old who weighed nearly 275 pounds at the time, barely made it–and hobbled back to his doorstep. Yet, he refused to quit and increased his distance daily; it was three months before he ran a mile, but the challenge changed his life.

Now, Radin, a marketing copywriter in Los Angeles, exercises for an hour most days of the week. He is a lean, muscular 170 pounds. At an annual checkup, his physician remarked that his low blood pressure and cholesterol were likely an improvement from even before he gained excess weight in the late 1990s.

In Depth: Why Skipping Exercise Can Be Deadly

“Losing a lot of weight and changing your body has a profound impact,” Radin says.

More than he may expect, it turns out. According to a study of more than 4,300 people published this summer in the journal of the American College of Sports Medicine, the least-fit individuals had a three-fold increased all-cause mortality risk and a nearly four-fold increased cardiovascular mortality risk when compared to the most fit. In other words, improving your fitness level can better your chances for a longer life.

That study is just one in a recent spate of research in children and adults that draws connections between physical inactivity or obesity and poor health outcomes. It’s no secret that exercise is critical to excellent health, but many of us let the week slip by with nothing more than a brisk walk to the parking lot. Yet, neglecting one’s weight and fitness is a certain path to increased risk for life-shortening ailments and conditions.

Exercise as Medicine
While physical activity is just one component of developing fitness–the others include overall health and genetic predisposition–exercise is essential.

The ideal amount, says Jonathan Myers, Ph.D., a co-author of the ACSM study and a health research scientist at the VA Palo Alto Health Care System in northern California, is a half-hour of moderate-intense activity five days of the week. Even better is an hour of exercise most days of the week.

When Myers and his co-authors separated their 4,300 participants into different fitness quintiles and studied them for nearly 20 years, the ones that performed the best reached that five-hour-a-week threshold. Those with the poorest fitness had a three-fold increase in overall mortality risk; 170 participants in this category died of all causes while only 55 in the highest quintile died.

“We’ve been chasing this for the last 20 years or so,” Myers says of the results, “and we’ve seen it over and over again.” Fifty years of epidemiological studies, he says, have demonstrated that people who are more fit or are more physically active have lower mortality rates.

A study published last week in the British Medical Journal found a similar correlation between weight gain and maintaining optimal health into old age. Of the 17,000 women who participated in the 20-year observational study, those who were overweight at age 18 and gained more than 22 pounds by 50 had the worst odds for optimal health. For every 11 pounds gained during that time, the chances for “healthy survival” decreased by 5%.

But it’s never too late to start exercising. Myers’ research shows that there are tremendous benefits to be had for the worst-off individuals who can change their ways. When the co-authors compared the least-fit group to the next least-fit group, they noticed a striking difference: The two-fold increase in mortality risk was predominantly due to variations in physical activity, not other risk factors like hypertension and diabetes.

“We don’t know yet why exercise has such protective benefits,” says Myers, “but your fitness level can outperform the traditional risk factors”–such as smoking and high blood pressure–”in predicting mortality.”

The Kids Aren’t Alright
Though fitness often becomes a major concern in adulthood, when aging and the onset of chronic disease makes exercise imperative, there’s increasing evidence that physical activity in childhood has significant long-term implications for health.

Kathleen F. Janz, a professor in the departments of Health and Sport Studies and Epidemiology at the University of Iowa, found in a recent study that children who lead less active lives are more likely to be overweight years later.

Janz studied 333 5 year olds over eight years by monitoring their physical activity with a device known as an accelerometer and measuring the subjects’ fat mass with body imaging. The protective benefit of physical activity, according to Janz and her co-authors, continued through childhood; the most active children at age five had significantly lower fat mass at eight and 11 compared with those in the lowest quartile.

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“It’s not unusual that there are windows of opportunity for critical periods where it’s most important to do it right,” says Janz. Childhood is one of them, she adds.

It’s not just fatness that matters, either. A recent study in Circulation found that some Type 2 diabetic and obese teenagers have a thicker carotid artery, an association that had only been seen previously in adults and one that may put them at greater risk for stroke and heart attacks later in life.

Yet, like Jonathan Myers at the Palo Alto Health Care System in northern California, Janz says the protective benefits of exercise are immediate, regardless of how long it’s been since the last workout. Certainly, Dan Radin considers himself an example of what can be accomplished with enough determination and direction.

“I hadn’t grown up playing sports,” he says. “Exercising was something I had to figure out.”

But he’s far beyond using the corner block as a benchmark or gateway to a longer, healthier life; his next target is a triathlon.

Studies suggest that people might have a genetic predisposition to enjoying exercise.

From LATimes.com:

For decades, fitness gurus have admonished sofa spuds to adopt a can-do attitude toward exercise, as if the only thing keeping them from the gym or walking path was the right attitude.

Yet a growing body of evidence suggests that it’s not merely motivation but also genetics that separate slouches from fitness fanatics, and at least some of these genes appear to act on the brain’s pleasure and reward center.

Though the science doesn’t imply that people disinclined to exercise can’t get moving, it helps explain why some people find it more difficult than others to “just do it.”

“We all know people who can’t sit still and we all know people who can’t get off the couch,” says J. Timothy Lightfoot, an exercise physiologist at the University of North Carolina in Charlotte.

Studies of twins suggest that some of the differences between these types of people come down to genetics. A 2006 Swedish investigation looked at leisure-time physical activity in 5,334 identical and 8,028 fraternal twins. The findings revealed that the exercise habits of identical twins were twice as closely matched as those of fraternal twins.

Fraternal twins share half their genes on average, whereas identical twins are genetic duplicates, so the finding implies that genes account for much of the variability in physical activity levels between people.

Likewise, a 2006 study that pooled data on exercise participation in more than 37,000 twin pairs from seven European countries calculated the genetic influence on physical activity at somewhere between 48% and 71%.

And these are not isolated findings.

“We now have more than 20 twin studies showing almost unanimously that [identical] twins are more alike in their physical activity than [fraternal] twins,” says geneticist Claude Bouchard, executive director of the Pennington Biomedical Research Center in Baton Rouge, La. The studies make a compelling case that the inclination to exercise runs in families, he says.

Studying mice

In an effort to find the genes involved, physiologist Theodore Garland at UC Riverside turned to rodents. He placed exercise wheels in the cages of ordinary mice and measured how often they scurried around in the wheels.

“This was voluntary exercise,” Garland says. “It’s sort of like how some people jog and others don’t.”

Researchers then selected the mice who ran the most and bred them with other so-called “high-runners” and repeated the experiment for more than 50 generations.

The result was a strain of high-runner mice that run as many as eight hours per night.

Garland’s next step was to find out what caused the mice to want to run. He found clues in the brain.

In a study published in 2003, his group showed that high-runner mice and regular mice respond differently to stimulants such as cocaine and Ritalin. Regular mice would run more when plied with the stimulants. “But we’ve never found a drug that will increase running in high-running mice,” he says. Whatever those drugs do in the brain seemed to be already turned on in the high-runner mice.

Because cocaine and Ritalin alter levels of the brain chemical dopamine, a neurotransmitter involved in pleasure and reward, the drugs’ different effects on the two breeds suggest high-runner and regular mice may process dopamine differently in the brain — and that may dictate how much pleasure they get out of running.

Other studies have also linked physical activity to dopamine.

For instance, a 1998 study showed that mice deficient in a receptor involved in processing dopamine, the D2 receptor, are less active than those with normal D2 receptor levels.

More recently, Lightfoot and his colleague Amy Knab found that two other dopamine-related genes were less active in their high-runner mice.

Says Knab, who is an exercise physiologist at Appalachian State University, “There’s something inherently different in the dopamine systems of the high-runners versus low-runners.”

Human studies have also linked exercise frequency to dopamine. Bouchard’s research team studied physical activity levels in a sample of 721 volunteers from 161 families in Quebec, Canada. They found that variations in the dopamine D2 receptor gene correlated to physical activity levels in women, but not men.

It’s a start

Bouchard says the study is an intriguing start — but he speculates that there are many more genes that influence exercise inclination.

Environment still plays a major role in how much someone exercises, though. “You can’t blame being lazy on your genes,” Knab says.

In fact, a twins study published last year suggests that environment trumps genetics when it comes to the kind of exercise needed for good health.

When University of Washington exercise physiologist Glen Duncan and his colleagues examined data from the university’s twin registry they found that genetics did predict the propensity to exercise up to 60 minutes per week.

But at 150 minutes or more — the amount of exercise that public health officials recommend — “the genetic component went away and the environment was the bigger factor,” Duncan says. For example, if people walk into a building and see a set of stairs first thing, they will probably take them. But if there’s an escalator front and center, they’ll take that instead, he says.

Researchers are now trying to tease out the ways that genes and the environment combine to turn one person into a marathon runner and another into a couch potato. By doing so, they may discover more effective ways to encourage exercise among those not naturally inclined.

“It’s really hard to change people’s physical activity levels,” physiologist Joey Eisenmann at Michigan State University says.

“There are a lot of people working on interventions to increase physical activity, and for the most part they haven’t been shown to be highly effective. As we learn more about genetic factors, that may shed light on why these programs don’t work as well as we’d like.”

Some of this research may eventually lead to more individualized approaches to fitness.

Or — failing that — researchers may even learn to enhance exercise’s gratifying effects with drugs.

“Some day,” Garland says, “we could be giving people pills to make it more pleasurable to run.”

From LATimes.com:

If people would just do four things — engage in regular physical activity, eat a healthy diet, not smoke and avoid becoming obese — they could slash their risk of diabetes, heart attack, stroke or cancer by 80%, a new report has found.

But less than 10% of the 23,153 people in the multiyear study — published in Monday’s Archives of Internal Medicine — actually lived their lives this way.

“The study has such a simple straightforward focus on making the point that prevention works in preventing serious disease,” said Dr. J. Leonard Lichtenfeld, deputy chief medical officer for the American Cancer Society.

“What really has been difficult is trying to figure out how to get people to take notice of the message and engage in healthy behaviors.”

Researchers at the U.S. Centers for Disease Control and Prevention and in Germany examined the habits of German men and women ages 35 to 65 from 1994 and 1998. At the start of the study, the scientists measured participants’ heights and weights and asked them about their diseases, lifestyle habits and diets.

Healthy factors included never smoking; engaging in physical activity for at least 3 1/2 hours each week; eating a diet low in red meat and high in fruits and vegetables; and having a body mass index lower than 30. (A person with a BMI of 30 or above is classed as obese.)

About 9% of participants practiced all four healthy lifestyle choices.

Four percent practiced none.

Roughly 35% followed two of the healthy practices.

Researchers reviewed participants’ medical records about eight years later, on average, looking for diabetes, heart attacks, strokes or cancer. People who followed all four healthy practices were at far lower risk compared with people who followed none: 93% lower risk for diabetes, 81% for a heart attack, 50% for a stroke and 36% for cancer.

For people who had never smoked and who maintained a BMI under 30, the risk of chronic disease was reduced 72% — the most dramatic reduction of any dual combination of healthy factors.

The scientists also found that each healthy factor reduced chronic disease risk.

A BMI under 30 lowered overall disease risk most — particularly for diabetes.

Never smoking reduced heart attack risk the most of all four factors.

“All of them are important, and trying to pick one is like asking someone to pick their favorite child,” said study coauthor Dr. Earl S. Ford, a senior scientist in the CDC’s Division of Nutrition, Physical Activity and Obesity.

Dr. Vyshali S. Rao, chairwoman of cardiology at Huntington Hospital in Pasadena and an American Heart Assn. spokeswoman, said the study underscores that shifting to a healthier diet helps the heart even if a person remains overweight.

However, she said, people who alter their diets often find they lose weight as a side benefit.

“Cardiologists try to stress to their patients more and more [that] cardiovascular disease is in hands of each individual patient to change,” Rao added.

The study’s findings, which are consistent with investigations that started in the late 1990s, are likely to apply to people living in the United States as well as those in Germany.

“The strongest reductions in risk for diabetes and [heart attack] are not surprising,” said Dr. Rachel Ballard-Barbash, associate director of the National Cancer Institute’s Applied Research program. “Even within a few years’ time, we can see changes in these diseases associated with these health behaviors,” such as lowered levels of LDL cholesterol and blood pressure.

“For stroke and cancer,” she added, “most studies would suggest it would take longer to see changes.”

Heart disease, cancer and strokes are the top three causes of death in the United States, killing an estimated 1,328,643 people every year, according to the CDC. Diabetes is the sixth cause of death, killing 72,449 annually. Many additional people live constrained lives in poor health because of these illnesses.

From LATimes.com:

When Gaetano Vaccaro meets with depressed patients at Moonview Sanctuary, he sometimes moves part of the session outside, taking a walk while talking. The result: “People’s state of mind can shift.”

Depression can spawn a spiral of lethargy and hopelessness, so that the last thing someone wants to do is exercise. But regular, moderate physical activity may lessen depression symptoms as much as some medications.

“On its own, exercise does appear to have significant effects in terms of elevating mood,” says Dr. Andrew Leuchter, professor of psychiatry at the UCLA Semel Institute for Neuroscience and Human Behavior. Physical activity, he adds, is often used to augment treatments such as medication and cognitive behavioral therapy. “If people are on medication or in treatment and haven’t had a complete recovery from depression, exercise is useful in getting them all the way there.”

Exercise affects the brain in several ways. “People with depression tend to become somewhat inert, and they don’t engage in their usual activities, and exercise gets people back to their usual level of activity,” Leuchter says.

That can prompt an upward cycle, inspiring people to return to work and connect again with friends and family, ultimately providing motivation to stay on course. Such connections are crucial for depressed people.

“The psychological benefits make a big difference from my perspective,” says James Blumenthal, professor of medical psychology at Duke University in Durham, N.C. “People have a greater sense of being in control. They feel better about themselves and have more self-confidence.”

A physical change can instigate a mental change, says Vaccaro, director of development at Moonview Sanctuary, a psychological treatment center in Santa Monica. “When you’re getting somebody to move and getting them to change a pattern in their life, just that little bit of pattern change can relate to a mood change, and they start to see themselves as a person who is active, not just a couch potato. They change their perception.”

There may be direct physical effects on the brain as well.

The treatment center encourages exercise — yoga in particular — as a way to manage many types of mood disorders. Besides having a strong mind-body connection, “yoga is something that can be modified to someone’s activity level and is something they can do throughout their life,” Vaccaro says.

Mood elevation

Several studies illustrate the benefits of exercise. In one, published in the journal Psychosomatic Medicine in 2007, 202 men and women with major depression were randomly assigned to participate in a supervised exercise program in a group setting, do home-based exercise, take an antidepressant medication or take a placebo pill. After 16 weeks, 41% were in remission, meaning they no longer had major depressive disorder. Those who were in the exercise and medication groups tended to have higher remission rates than the placebo group.

Another study examined how much cardiovascular exercise was needed to see changes in mood among those with mild to moderate major depressive disorder. The 80 men and women who took part in the research were randomly placed in four exercise groups that varied in the number of calories burned and the frequency of the activity. A placebo group did flexibility exercises three days a week.

Those in the group that exercised at moderate intensity three to five days a week for about 40 minutes (consistent with public health recommendations) showed the biggest decrease in depressive symptoms compared with those who exercised less, or just did stretching. The 2005 study appeared in the American Journal of Preventive Medicine.

Other pieces of the puzzle are still missing, however. Scientists aren’t sure what changes happen in the brain — and why — when people exercise.

Many scientists and physicians believe that exercise increases levels of serotonin, a neurotransmitter thought to be linked to mood regulation. However, most of the studies supporting this have been done on animals.

“It’s hard to quantify it in humans for a number of reasons,” Leuchter says. “We don’t entirely understand exactly why patients get depressed in the first place. We have theories, but it’s hard to know in individual cases. And we don’t have a good way of looking at [changes] in the brain.” Scientists do know that exercise causes an increase in blood flow to the brain and raises the amount of energy the brain uses. And even though the link between blood flow and mood isn’t known, Leuchter says, “the brain in general seems to be in a healthier state.”

Activity is key

Exercise may be key in fighting depression, but no generic prescription fits everyone. Overall health and exercise history factor into what kind of regimen might be prescribed.

“If someone was a runner, I’d get them back to running,” Leuchter says. “If not, I’m not going to have the goal of turning someone into a major athlete. I’d simply want to get them active, and even walking around the block might be good.”

Those who aren’t currently in treatment for depression should consult with a physician before exercising to make sure they have no underlying health problems. Patients who are on medication or in therapy for depression shouldn’t consider exercise a substitute for either treatment.

“The key,” Blumenthal says, “is really maintenance. You have to do it on an ongoing basis. You should find something you enjoy, but doing something is better than nothing.”