By Lisa Ziegel
There is a long list of diseases and conditions that can be prevented or helped by exercise and other healthy habits. One that is particularly deadly is cancer. According to the American Cancer Society, more than 1.6 million new cases of cancer are expected to be reported in the United States in 2013. Nearly half this number of individuals will die, making this the second leading cause of death preceded only by heart disease. This includes various types of cancer, led by those with a strong correlation to tobacco use (most commonly affecting the lungs and bronchial system).1 We know that these are mainly preventable by avoiding tobacco. As for other types of cancer, there is a common set of preventive measures that can lessen the chances that one will get it. These include consuming a variety of vegetables and fruit, cutting down on red meat and alcohol, getting screened regularly (particularly if there is a genetic history and after age 50), and not of the least importance, engaging in physical activity.
Exercise is known to have a myriad of positive effects on health, and there is strong evidence that it has a protective effect against certain cancers. This was studied in 2001 when researchers combed through several studies to find a causal relationship between activity and primarily cancers, such as colon, breast, and prostate.2 One major finding was that 39 out of 46 studies showed "convincing" evidence not only of an epidemiological relationship between activity and the reduction of risk in colon cancer, but also a strong possibility of an etiologic effect. In other words, an outcome was not just observed, but there was a physical reason found. Physical activity of course helps keep bodyweight in a healthy range as well as body composition (lean vs. fat weight) and often encourages the practice of other good habits, such as eating the right foods and consuming more water. Along with adequate fiber intake, the movement of waste matter through the system is facilitated, resulting in a healthier colon.
In regard to breast and prostate cancer, exercise helps by regulating both the hormones insulin and estrogen. In addition, exercise can keep abdominal fat in check. Visceral fat is known to have its own metabolic activity, which correlates to a high incidence of colorectal and other cancers. The same exercise guidelines that apply to all healthy individuals apply to cancer prevention – that is 150 minutes of moderate intensity or 75 minutes of vigorous intensity activity each week, or an equivalent combination, preferably spread throughout the week. In addition, increasing the amount of movement in daily activity, such as taking stairs whenever possible, standing more instead of sitting, or doing your own housework or yard work should be included. Encouraging kids to get out and play vs. sitting behind a computer, video game, or TV can get them started on an active lifestyle as they get older and set the groundwork for avoiding cancer later in life. Of course, despite practicing healthful habits, people do get cancer for other reasons. Treatments for cancer, such as chemotherapy, invasive surgeries, etc. can be physically draining. However, exercise can help here too. A well-designed and supervised exercise program can help the patient gain energy and maintain strength (it is especially helpful in maintaining muscle and bone mass, which might otherwise be lost). Coordination with the person's medical team is essential so that everyone is on the same page - - the more encouragement and support, the better.
An initial assessment of strength and endurance can serve as a baseline to measure progress or to help determine what is not working when re-assessments are conducted. According to the individual's preference of mode -- walking, stationary cycle, elliptical, or even dance aerobic classes (there are even classes designed specifically for cancer patients) are great, starting out at a moderate intensity, of course. Moderate exercise is known to boost the immune system, but high intensity or anything that results in muscular pain or fatigue are not recommended as these may be harder for a compromised system to recover from. Also, just as moderate exercise can stimulate appetite that is lost due to chemotherapy treatments, too much intensity can suppress this.
To maintain muscle mass, strength, and energy, resistance training is another essential component, performed at least two times per week according to ACSM guidelines for beginners (one to two sets of 8-10 exercises at 10-15 repetitions, not necessarily to fatigue). Of course, attention must be given to each individual's limitations and day-to-day changes that may occur, so intensity must be adjusted accordingly. For stress relief and to complement cardiovascular and strength training, yoga or a similar mind-body practice would make an excellent addition. No surprise, but exercise is again identified as a major component in reducing the incidence of disease, along with practicing other healthy behaviors. In those who do have cancer, it can improve the quality of life, boost mood, and increase self-esteem and self-efficacy, proving if we make it an essential part of our lives, we can all benefit.