I write a lot about exercise because it has been so important in my life. I have used exercise to control my weight, reduce my stress, look younger and feel better. For me exercise has given me a great return on my investment of time and energy. I really can’t understand why everyone doesn’t exercise, but research indicates that 25 to 35 percent of Americans are inactive.

Unfortunately inactivity can have dire consequences. The term Sedentary Death Syndrome, or “SeDS,” has been used by leading physiologists to identify chronic, preventable diseases related to inactivity. I hope that a recently released book, The First 20 Minutes: Surprising Science Reveals How We Can: Exercise Better, Train Smarter, Live Longer, by Gretchen Reynolds will help people change their attitudes about exercise. The research findings are encouraging from the standpoint that it really doesn’t take a lot of exercise to get the benefits. In fact, the research indicates that sedentary people can prolong their lives and reduce the risk of disease in as little as 20 minutes of exercise a day.

The key word to improving your health and reducing disease threat is movement. Think yard work, gardening, house work, and walking – anything that gets your muscles contracting and your blood flowing. The research challenges the idea that movement must be strenuous and lengthy in order to produce benefits. The important thing is to move or, perhaps more importantly, to not be sedentary. In her book, Ms. Reynolds talks about the physiological effects of inactivity. The research finds that if the big muscles in your legs don’t contract for hours, there are physiological changes in your body that exercise won’t necessarily undo.

An article exploring the cancer survivors and exercise may shed some light on the protective nature of movement. A new major review published this month, by scientists at the National Cancer Institute looked at 45 studies dating back to 1950, although most studies were published in the last five years. These studies focused on the physical activity among people who’d received a diagnosis of cancer. The types of cancer included prostate, ovarian, brain and colorectal. However, the majority of the studies were women with breast cancer.

The review found that almost all of the studies showed that regular physical activity “decreased the risk of cancer-related mortality and of all-cause mortality,” according to Dr. Ballard-Barbash lead author of the study. The study found that exercise consistently improves insulin levels, reducse inflammation and increases populations of the very immune system cells that are thought to attack tumors - these are all biomarkers related to cancer.

According to the study, exercise made the cancer survivors healthier and far more likely to enjoy a longer life span than if they were sedentary. Interestingly, exercise did not seem to increase fatigue among most survivors. More often, it lessened it.

Researchers found similar results in another new study published this month, this one involving colorectal cancer survivors in the Netherlands. Those who exercised reported much less exhaustion and, in general, greater health-related quality of life than those who did not. “Fatigue and the fear of tiredness may be a barrier to physical activity for some people” who’ve survived cancer, said Laurien M. Buffart, a professor at VU University Medical Center in Amsterdam, who led the study. “But more and more evidence suggests the reverse,” that exercise energizes people who are undergoing or have completed cancer treatment.

This study confirmed that the exercise did not have to be strenuous. “In our review, the most common activity was walking,” Dr. Ballard-Barbash said, “which happens to be an activity that is within the scope of almost anyone.” As a word of caution, please consult your doctor before beginning an exercise program if you have been diagnosed with cancer, or if you have been inactivity for a number of years.

If you are a frequent reader of our blog posts, you know that Dr. Grandma's is a strong advocate of exercise, not only for reducing the risk of cancer, but to reduce the risk of many other diseases of our current civilization as well. As a frequent reader of our blog posts, you also know that Dr. Grandma has written a number of excellent posts on the power of a healthy diet and feels strongly about the role that good nutrition plays in reducing the risk of disease. We feel that attending to all aspects of a healthy lifestyle - exercise, diet, stress reduction, and adequate amounts of sleep is vital to life, health, energy, and joyful living. While our blog posts seek to clarify the best research findings, we have also stressed that each individual thrives best when his or her own program is developed, consistent with the research broadly, but individualized. We recommend adapting a lifestyle strategy and tactics that suits your individual tastes and preferences and works for you. The good news is that it isn't as difficult as you might have imagined.