TOTAL LIFETIME FITNESS

Diabetes and Exercise

October 7th, 2008 Posted by David Lemberg

A diabetes epidemic has been sweeping the globe for many years. In 2005, an estimated 21 million people in the United States had diabetes – 7% of the population. African-Americans, Hispanic-Americans, and older people are at increased risk.

The majority of affected persons have adult-onset diabetes – non-insulin-dependent diabetes mellitus [NIDDM] – which begins as “insulin resistance”. Insulin resistance occurs when normal amounts of insulin fail to produce a normal response in muscle, liver, and fat cells.

Insulin-resistant muscle cells are unable to absorb sufficient amounts of glucose from the blood, reducing levels of glycogen (complex chains of glucose) storage in muscle. Insulin-resistant liver cells likewise have reduced storage of glycogen. Insulin-resistant fat cells breakdown stored triglycerides which raises the levels of free fatty acids in the blood.

None of this is good. The long-term results of insulin resistance are increased blood glucose and increased blood lipids – in other words, diabetes and high cholesterol. High blood pressure, heart disease, and associated symptoms of diabetes develop over time.

The abnormally high blood sugar levels that are characteristic of diabetes may have severe long-term consequences, including damage to blood vessels and nerves, cardiovascular disease, and eye disease (diabetic retinopathy).

Of great interest is the well-established consensus that insulin resistance and NIDDM are lifestyle disorders – they result from less-than-optimal lifestyle choices (chronic overeating and lack of physical exercise) and may be significantly improved by healthful alterations in a person’s lifestyle.

Peer-reviewed research worldwide has consistently demonstrated that exercise and dietary modification are important components of the treatment of adult-onset diabetes.

Bottom line – it’s very important for young people and young adults with insulin resistance and older people with NIDDM to begin a program of regular, consistent exercise. In 2007 a major study found that improved control of blood sugar levels resulted from a combined program of aerobic exercise and strength training.¹ Control of blood sugar levels is critical in preventing the long-term severe symptoms of diabetes.

And, studies clearly show that regular exercise lowers body fat, lowers blood pressure, and normalizes blood levels of fat-transporting proteins.

So, exercise is a critical lifestyle factor for people with either insulin resistance or adult-onset diabetes. Importantly, it’s never too late to start an exercise program. But, medical evaluation and guidance are necessary before beginning.

A complete physical examination is necessary to reveal long-term complications of diabetes or the potential for such complications. It’s particularly important to identify peripheral neuropathy, microalbuminuria, and/or proliferative retinopathy (nerve system disorders, kidney disease, and eye disease).

For individuals over age 35, a stress test may identify abnormal blood pressure responses and/or insufficient blood supply to the heart (ischemic coronary disease).

If any of these complications of diabetes are discovered, the person may exercise with appropriate modifications. Strength training and high-intensity aerobic exercise should only be done by individuals without high blood pressure or proliferative retinopathy.

Important general guidelines include drinking sufficient quantities of water throughout the day [a good rule of thumb – when you're thirsty, it's already too late]. Proper footwear and daily foot inspections are necessary, particularly for those with peripheral neuropathies.

Regular, consistent exercise is important for everyone, and especially important in the long-term management of insulin resistance, adult-onset diabetes, obesity, and high blood pressure. For pre-diabetics and diabetics, medical evaluation and guidance will help ensure safe, beneficial physical exercise. The long-term goals of exercise- and food plan–based lifestyle modifications are reduced diabetes symptoms and increased health, well-being, and longevity.

Importantly, in terms of prevention, studies in the 1990s showed that physically active individuals are much less likely to develop insulin resistance and adult-onset diabetes.²

These studies are more than 10 years old. It’s up to each of us to effectively use this information and take on the lifestyles that ensure our long-term health and happiness.

Exercise is a powerful force for good in the world!

¹Wallberg-Henriksson H, et al: Exercise in the management of non-insulin-dependent diabetes mellitus. Sports Med 25(1):25-35, 1998
² Ivy JL: Role of exercise training in the prevention and treatment of insulin resistance and non-insulin-dependent diabetes mellitus. Sports Med 24(5):321-326, 1997

Technorati Tags: aerobic exercise, diabetes, Strength Training