Compass: Walk on Saturday; it'll do your heart good

On Saturday, the 2013 Anchorage Heart Walk takes place. The Heart Walk is a great community gathering for an excellent cause. Participants walk along a beautiful 3.1-mile course through parts of downtown, the Coastal Trail and Westchester Lagoon. It is a fundraising event for the American Heart Association and an opportunity to share with others who are committed to a healthy lifestyle.

Heart disease affects most Americans in some way. It is the leading cause of death for two-thirds of both men and women in our country. The risk factors associated with the development of cardiovascular disease have been well established: age, family history, diabetes (or high blood sugar), hypertension (or high blood pressure), smoking and high cholesterol. The good news is that many of these risk factors associated with heart disease can be modified through lifestyle changes. Incorporating an exercise program has been shown to reduce high blood pressure, high cholesterol and diabetes. An exercise program based on walking can engage the whole family, is not expensive and has the lowest dropout rate of any exercise program.

The potential benefits of walking affect sedentary people the most. An employee sitting at a desk expends the same amount of energy required to sleep. The slowest walking (even less than 1 mile per hour) doubles this rate. For every hour of walking, life expectancy may increase by two hours. A Harvard study concluded walking at a moderate pace (3 mph) for up to three hours per week can cut the risk of heart disease in women by as much as 40 percent. Another study showed women's diabetes risk was cut in half.

Walking for at least 30 minutes a day, most days of the week, has been shown to be beneficial. Generally a 20-minute walk takes about 2,000 steps and equals a mile. Sadly, Americans walk the least amount of any industrialized nation. We trail Australia, Japan and the Swiss. Australia takes 9,695 steps a day, Japan 7,168, the Swiss 9,650; the average American just 5,117 steps a day. Despite this fact, walking is the most popular form of exercise in the United States.

It might seem intuitive that walking is so healthful. After all, humans migrated across the planet on foot to become the dominant species. But it has only been through the last half of the 20th century that the medical community began to view exercise as more central to public health. It was only recently that science discovered mechanisms by which walking lowers cholesterol and blood sugar.

Walking at a moderate pace increases heart rate and respiratory rate, which utilizes more glucose, which can then lower blood sugar, levels and make the insulin in our body work better. The enzymes have been discovered that move the bad cholesterol (LDL) from the bloodstream to the liver, where they can be excreted for digestion as bile. The more you walk, the more LDL your body expels.

Researchers have found that three 10-minute walks each day can be even better for blood pressure lowering than a 30-minute session. Both groups lowered their blood pressure during the day and evening of exercise but the multiple sessions had an effect the following day.

The 2013 Anchorage Heart Walk embodies these principles in a great community event. Thank you to all the participants, volunteers, sponsors and supporters who make these community gatherings inspirational for all of us.

Dr. Lisa Gray is a cardiologist at The Alaska Heart Institute. Heart Walk festivities begin at 9 a.m. Saturday at the west end of the Delaney Park Strip downtown, near the rose garden. The walk begins at 10 a.m. More information is at