The health benefits of exercise have been known for decades, and yet approximately 75 percent of people in the U.S. are considered sedentary — engaging in irregular or no physical activity. Aside from its direct physical benefits, exercise is also among the best ways to fight obesity and reduce stress, two other risk factors for gastrointestinal disorders.
Physical activity affects the entire body. Regular exercise can lower triglycerides and raise HDL cholesterol (the "good" kind), increase insulin sensitivity, improve glucose tolerance, and bring more blood and oxygen to all parts of the body. All these changes mean that each body system, including the gastrointestinal system, can function optimally.
How much exercise should you get? You should get at least 30 minutes or more of moderate-intensity exercise every day. You don't have to do all 30 minutes at once; 10 minutes walking the dog in the morning and 20 cutting the lawn in the evening will count towards your 30 minutes. For greater fitness benefits, work up to 20 to 60 minutes of continuous exercise, five days per week. The keys to building exercise into your lifestyle are:
- Choose an activity you enjoy. If you don't like running, try walking … or swimming or bicycling or rollerblading. Exercise is not a punishment.
- Start slowly and build the amount of exercise you do gradually. If you start out too quickly, you may injure or over-tire yourself. If a 10-minute walk is all you can do on Day 1, try 11 minutes on Day 2. As you exercise longer, you'll gain strength and endurance.
- Vary the types of exercises you do. Some people quit exercising when they become bored. Look for new activities you can intersperse with your current routine. Try tai chi (a gentle movement-based martial arts program), rock climbing, dancing or jumping rope.
- Before beginning any program of exercise, see your doctor, especially if you have hypertension, high cholesterol, diabetes, or a family history of heart disease.
Specific GI disorders that are affected by level of physical activity include:
Regular exercise can prevent constipation. Although the exact mechanism for how exercise affects constipation isn't known, people who exercise regularly are more likely to have food travel through the large intestine at a faster rate. A faster transit time means less time for water to be absorbed from the stool in the colon, resulting in looser stools that are more easily passed.
Cancers Of The GI Tract
People who have a lifetime pattern of sedentary habits have a higher risk of colon cancer compared to people who are physically very active. Although research is still being conducted to determine how exercise helps to reduce colon cancer risk, two theories have been proposed:
- Exercise may increase fecal transit time through the colon, which means that food passes quicker through the body. Any toxins or carcinogenic substances eaten with food (pesticides, for example) spend less time in the body and therefore can do less damage to the cells of the colon lining.
- Exercise has been shown to boost immune function, which may play a role in halting cancer development.