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Get Down to Basics (Part 5)

Aug 8, 2006

Sheri Colberg, Ph.D., FACSM shares more of her new best seller, The 7 Step Diabetes Fitness Plan. This week read: But What If You Already Have Diabetes? You will want to print this one out and give it to your patients.

SheriStep 1: Get Down to Basics (Part 5)
But What If You Already Have Diabetes?

By Sheri Colberg, Ph.D., FACSM


But what if you already have diabetes?

There’s another, equally important, reason for getting up off the couch if you already have diabetes, and that is that regular exercise is the key to good control of BG levels. The glucose-lowering effects of exercise can mainly be ascribed to a heightened sensitivity to insulin in exercised muscle, an effect that persists for only a day or two following the activity. This means that in order to maximize exercise’s positive effects on BG control, you have to exercise regularly.

Daily or near-daily activities are recommended; any type of exercise makes insulin work better. When your body needs less insulin, your pancreas is more likely to be able to produce enough to meet your body’s needs, and your BG control will improve. If you already have diabetes, any training-induced improvements are likely to be even more pronounced, and you can enjoy improvements in your diabetic control without significant weight loss. By way of example, a recent study of Japanese men and women with either prediabetes or type 2 diabetes (but who took no medications) reported that physical fitness by itself is equally important in staving off metabolic derangements. In that study, people who were classified as “low fit”—regardless of the amount of abdominal fat they had—had the greatest risk factors for heart disease. Those who were “moderate fit” or “high fit,” though, had lower levels of insulin resistance, and the more fit they were, the better their fasting BG, insulin, and cholesterol levels, and their blood pressure readings.

Similarly, researchers in Finland found that if you have type 2 diabetes but engage in moderate or high levels of physical activity, you will be far less likely to die from heart disease than if you engage in only a low level of physical activity, regardless of your body mass, blood pressure, cholesterol levels, smoking status, or sex. People in the Finnish study who were moderately active (which included being active during work, during their commute to and from work, or during leisure time) reduced their risk of dying from heart disease by 39 percent, while highly active individuals had a 48 percent lower chance.

What walking by itself can do for your diabetes control

To prove the exact contribution of walking by itself, another recent study, the Diabetes In Control 10,000 step study, asked people with type 2 diabetes to increase their physical activity without changing their diets at all. Participants had to commit to taking at least 10,000 steps each day (equal to roughly 5 miles of walking), monitored with pedometers. A total of 44 diabetic adults completed the study, clocking in over 3 million steps, the equivalent of almost 15,000 collective miles over three months. For the diabetic adults in the study, many improvements occurred after just the first four weeks of the study. By the end of three months, over 15 participants had reduced their dosages of various medications (including diabetes-related medications), six had completely eliminated some medications, and three had gone off all medications completely, with no change in their diets and an average weight loss of only 4 measly pounds. The conclusion: if you wear a pedometer with a goal of becoming more active all day (increasing, say, from 3,000 steps to 10,000), you can improve your physical fitness level, BG level, cholesterol levels, blood pressure, and body weight.

Exercise can also prevent diabetic complications

Exercise may also play a role in preventing any potential complications related to poor glycemic control. Many diabetes-related complications (such as loss of sensation in the feet, eye disease, kidney problems, or heart disease) are related to having diabetes for a number of years, so the earlier it is diagnosed, the better your possible outcome. As you now know, diabetes is an extremely strong risk factor for heart disease, and physical inactivity increases your risk of dying from heart disease. With regular exercise, you can improve BG levels and reduce both contributors to heart disease risk at once.

Regular aerobic exercise also lessens the potential impact of most of the other cardiovascular risk factors, including elevated blood lipids (cholesterol and other blood fats), insulin resistance, obesity, and hypertension. High blood pressure is associated with higher levels of insulin, and regular physical activity can result in lower blood pressure and reduced circulating levels of insulin. If you have elevated blood pressure, though, it is best to avoid certain high-intensity or resistance exercises, which may cause blood pressure to rise dangerously high. Such activities include heavy weight training; near-maximal exercise of any type; activities that require intense, sustained contractions of the upper body—water skiing or wind surfing, for example; or exercises for which you must hold your breath.

Having diabetes, you also have a higher risk of joint-related injuries, so a moderate program of walking may be more suitable for you than a more vigorous activity such as running. Even walking on a regular basis can help you live longer. In fact, if you’re a diabetic adult of any age and walk at least two hours per week, you’ll have a 39 percent lower risk of dying from any cause and will reduce your risk of dying from heart disease by 34 percent. Some of my own research on older people with type 2 diabetes has shown that the skin circulation in their feet—where they are at risk for developing ulcers—is slightly improved right after exercise and from regular aerobic exercise training. Good BG control, then, when achieved with the help of regular physical activity, has the potential to prevent or delay almost all of the potential long-term health complications of diabetes.


In two weeks, I will share Part 6 of Step 1 from my latest book, The 7 Step Diabetes Fitness Plan: Living Well and Being Fit with Diabetes, No Matter Your Weight (2006). Information about all of my books, my many articles, my research, and more is available on my web site: www.SheriColberg.com.

Tip for the day: Those successful dieters who do not regain the weight they lost while dieting have a few key behaviors in common. Almost all of them continue to watch what they eat after they stop officially dieting; exercise regularly for close to 60 minutes a day (mainly walking); and eat a healthy breakfast every day.

See more features from Sheri Colberg, Ph.D., FACSM