By Dr. Mercola
Nearly 80 percent of Americans do not get the recommended amount of aerobic and muscle-strengthening activity recommended for optimal health.1
Far from being only a matter of weight loss or aesthetics, exercise is a crucial element of disease prevention and management, with the "side effect" of helping you maintain a healthy weight.
There's a reason why the late Dr. Neil Butler, gerontologist and psychiatrist who founded the International Longevity Center (ILC), said, "If exercise could be purchased in a pill, it would be the single most widely prescribed and beneficial medicine in the nation."2
Harvard Medical School also states, "Decades of research have determined that regular exercise is one of the most important factors in warding off cardiovascular disease, many types of cancer, diabetes and obesity."3 Simply by getting moving, you, too, can reap the many scientifically proven benefits that exercise has to offer.
Lack of Exercise Linked to Hard-to-Treat Heart Failure
If you have heart failure, it means your heart isn't pumping as well as it should be and, as a result, your body is probably not getting enough oxygen. In other words, you have a weak heart.
Once-simple activities, like walking or carrying groceries, may become difficult, and you may also experience fatigue, shortness of breath, fluid build-up and coughing.4
A 2017 study published in the Journal of the American College of Cardiology found a strong, dose-dependent association between low levels of physical activity, higher levels of overweight and obesity (as measured by body mass index [BMI]) and risk of overall heart failure.5
However, the risk was most pronounced with one subtype of heart failure — a particularly hard-to-treat variety known as heart failure with preserved ejection fraction (HFpEF), in which the heart becomes stiff, resists expansion and doesn't fill up with enough blood.
Many of the risk factors for heart disease, including high blood pressure, diabetes and obesity, were also lower among people who exercised more.
Overall, those who exercised the recommended amounts lowered their risk of HFpEF by 11 percent, while those who exercised more than the recommended amounts lowered their risk by 19 percent.6
There are few effective treatments available for this type of heart failure, and the five-year survival rate is just 30 percent to 40 percent,7 which highlights the importance of preventive strategies like exercise and healthy weight management.
Past research has also found that people who engage in at least 150 minutes of moderate exercise, or 75 minutes of vigorous exercise a week (the recommended amount), had a 33 percent lower risk of heart failure than inactive people.8
Exercise Improves Heart Disease Risk Among Obese Middle-Agers and Seniors
People who are overweight or obese are at an increased risk of heart disease, but being physically active might help to reduce or even negate this risk, according to research published in the European Journal of Preventive Cardiology.9,10
The study included more than 5,300 participants aged 55 years and older, who were categorized as having high or low levels of physical activity. During 15 years of follow-up, overweight and obese participants with low exercise levels had a higher risk of heart disease than normal-weight participants with high levels of activity.
However, overweight and obese participants who exercised often did not have a higher heart disease risk compared to the normal-weight frequent exercisers. This emphasizes that physical activity may matter more than body mass index when it comes to gauging your heart disease risk.
"Our findings suggest that the beneficial impact of physical activity on CVD [cardiovascular disease] might outweigh the negative impact of body mass index among middle-aged and elderly people.
This emphasizes the importance of physical activity for everyone across all body mass index strata, while highlighting the risk associated with inactivity even among normal weight people."
It's important to note that this study was conducted in Rotterdam, Netherlands, where people typically ride bikes to work and errands. Because of this, even the infrequent exercisers were exercising at least two hours a day, while the high-level exercisers reported four hours a day of activity or more.13
Exercise May Help a 'Bad' Heart
The idea that people should take it easy after having a heart attack or heart failure has been disproven. Exercise allows your heart to work more efficiently and may reduce narrowing of the arteries and other effects of heart disease.14
Exercise is highly recommended for heart failure patients, as it strengthens your heart, helps your body use oxygen and improves heart failure symptoms. Moderate exercise also lowers your risk of being hospitalized for heart failure15 and may slow the disease's progression.
Both heart-failure and heart-attack patients can benefit from getting up and moving as soon as their physicians give them the all clear.
A cardiac rehabilitation program can help you learn what target heart rate you should be aiming for during exercise. Also contrary to popular belief, it's not only low- or moderate-intensity exercise that you should be after.
High-intensity interval training (HIIT), which involves short periods of intense exercise broken up by periods of lower-intensity rest, may actually be among the most beneficial form of exercise for heart patients and is recommended for this population by the Mayo Clinic.16
Most patients are cleared to try HIIT after they're able to perform moderate-intensity exercise for 20 minutes. In one meta-analysis of 10 studies, people with a variety of heart problems (coronary artery disease, heart failure, hypertension and more) had significantly better results from HIIT compared to moderate-intensity workouts.
Specifically, the HIIT workouts led to nearly double the improvement in cardiorespiratory fitness compared to continuous moderate-intensity exercise.17
Physical Activity May Slow Memory Loss in Early Alzheimer's
Alzheimer's disease has grown to be one of the most pressing and tragic public health issues facing the U.S. With no known cure and the number of people affected expected to triple by 2050, the Alzheimer's Association estimates that by mid-century someone in the U.S. will develop Alzheimer's disease every 33 seconds.18
Exercise is once again important here, as it can also reduce your risk of the disease as well as help with treatment. In one study, patients diagnosed with mild to moderate Alzheimer's who participated in a four-month-long supervised exercise program had significantly fewer neuropsychiatric symptoms associated with the disease than the control group that did not exercise.19
Another study published in PLOS One revealed that a progressive walking program that led to participants briskly walking for at least 150 minutes each week was associated with improvements in functional ability in people with early Alzheimer's disease.20
Among some of the participants, the walking program also led to improvements in cardiorespiratory fitness, and this was in turn associated with improved memory performance and even increases in the size of their brain's hippocampus, a region of your brain important for memory.21
It's previously been suggested that exercise can trigger a change in the way amyloid precursor protein is metabolized, thus slowing down the onset and progression of Alzheimer's.
Exercise also increases levels of the protein PGC-1alpha. Research has shown that people with Alzheimer's have less PGC-1alpha in their brains and cells that contain more of the protein produce less of the toxic amyloid protein associated with Alzheimer's.22
Exercise May Reduce Cognitive Decline in Those at High Risk of Dementia
If you know you're at increased risk of dementia, for instance if a close family member has been diagnosed, it's even more important to adhere to a regular exercise program. In seniors who are at high risk of dementia, cognitive decline can be reduced with a comprehensive program addressing diet, exercise, brain training and managing metabolic and vascular risk factors.23
Exercise initially stimulates the production of a protein called FNDC5, which in turn triggers the production of BDNF, or brain-derived neurotrophic factor. In your brain, BDNF not only preserves existing brain cells,24 it also activates brain stem cells to convert into new neurons and effectively makes your brain grow.
Research confirming this includes a study in which seniors aged 60 to 80 who walked 30 to 45 minutes, three days per week, for one year increased the volume of their hippocampus by 2 percent.25 Higher fitness levels were also associated with a larger prefrontal cortex.
Exercise Reduces Breast Cancer Recurrence, Helps Prevent Cancer
In terms of cancer, exercise is also crucial for both prevention and treatment. In a meta-analysis of 67 studies that examined the most important lifestyle factors to help prevent breast cancer recurrence, exercise came out on top.26 Those who exercised regularly reduced their risk of dying from breast cancer by 40 percent compared to those who didn't exercise.27,28
Previous research has also shown that breast and colon cancer patients who exercise regularly have half the recurrence rate than non-exercisers.29 As for prevention, being fit in middle-age cut men's risk of being diagnosed with lung cancer by 55 percent and bowel cancer by 44 percent.30
High levels of cardiorespiratory fitness in middle age also helped men survive cancer, reducing their risk of dying from lung, bowel and prostate cancer by nearly one-third (32 percent). Not surprisingly, it also reduced their risk of dying from cardiovascular disease by 68 percent.
The degree to which exercise cuts your cancer risk varies depending on the type of cancer and other factors, but the data shows physically active individuals have a 20 percent to 55 percent lower risk of cancer than their sedentary peers. For example, compared to inactive people, active men and/or women have a 20 percent to 30 percent lower risk of breast cancer and a 30 percent to 40 percent lower risk of colon cancer.31
Further, an analysis of 12 studies that included data from 1.4 million people of a wide range of ethnic backgrounds from both the U.S. and Europe over the course of 11 years found that those who exercised more had, on average, a 7 percent lower risk of developing any kind of cancer and a 20 percent lower risk of cancers of the esophagus, lung, kidney, stomach, endometrium and others.32
What Are You Waiting For?
If you're an avid exerciser, keep up the good work. If you're looking for some motivation to get started, identify what it is you seek to gain from exercise. Homing in on the immediate rewards, such as being able to think more clearly and boosting your mood, may be more effective than "avoiding heart disease and cancer," but they're all rewards worth seeking.
Next, pencil it into your calendar like you would any other appointment — and just do it. The more you exercise, the more you'll experience the benefits and highs that go along with it, and the memory of the positive feedback helps motivate you to exercise the next time. Remember, also, that exercise is only one part of staying physically active. It's equally important to keep from being sedentary during your non-exercise hours by replacing too much sitting time with active movement.