By Lisa Ziegel:
We have been hearing it on the news for so long it is practically on repeat: The incidence of diabetes is continually on the rise. However, instead of spurring people into action to be proactive about preventing it or managing it better, a recent report conveys disturbing news – the epidemic has only gotten worse. Instead of 8.3 percent of all Americans being diagnosed as type 2 diabetics (in 2010), in 2012, the number went up to 9.3 or 29.1 million vs. 25.8 million. Not only that, but millions more have the disease and are not aware of it – meaning they must be ignoring the telltale symptoms that include unmitigated thirst, frequent urination, lack of energy, and more. By the time these signs have been experienced, chances are the results of a blood test for glucose levels will determine the diagnosis after the fact.
Sadly, these figures are all the more distressing because pre-diabetes or insulin resistance can be caught before it’s too late if people keep up with their regular check-ups; even more so, however, because this is a disease that can be prevented. There are risk factors that make it harder for some people to avoid getting it, such as heredity (through a parent or sibling), race (Hispanic, Native Americans and African Americans are among the more susceptible), and people over age 45 tend to be diagnosed more often, although its prevalence is reaching much younger age groups, especially children.
We all know that physical activity is a good way to help to prevent or manage diabetes. With news of the latest scientific research just released, which revealed one of the mechanisms through which the disease develops, the role that exercise plays in alleviating the progress of this disease becomes even more apparent.
It has been well known for some time that a high-fat diet causes inflammation in the cells, which leads to insulin resistance, and ultimately, diabetes, among other complications. Recent research conducted on mice has found another factor that contributes to this development. The increased inflammation of fat in cells also causes decreased access to oxygen by the energy-producing components of cells, the mitochondria, creating a deficiency of oxygen for the function of the rest of the cell. This lack or oxygen creates a feedback system signaling the cells to release an inflammatory-protective response. Ongoing inflammation and accumulation of fat left unchecked eventually results in the further increase in insulin resistance, and then ultimately, diabetes. This is why an anti-inflammatory diet is so important in managing diabetes.
So now that we have a better understanding of how a high-calorie, high-fat diet contributes to “diabesity” (a not-very-kind term for the close link between obesity and diabetes), we can also better understand how physical movement can fight this.
First, we know that “aerobic” exercise, meaning “with oxygen,” utilizes stored body fat as its main source of energy. When your body gets moving, whether you walk, ride a bike, swim or use an elliptical machine, you are stimulating the muscles, which store glycogen (a form of energy coming from dietary intake of carbohydrate-rich foods) to utilize this stored energy. Exercise diverts blood sugar to the muscles, where it might otherwise circulate throughout the body and cause damage. This happens in part due to an increase in the number of capillaries that increase oxygen transport and increase the number of cell mitochondria as well as increased oxygen capacity within. Muscle contraction also facilitates the transport of glucose into the cell. As noted above, part of this energy also comes from fat stores, more so when one reaches a “moderate” level of effort and sustains this for a period of time. This happens when blood flow starts to increase as a result of physical movement, which triggers the release of fatty acids from circulating fat or fat storage to be delivered to the working muscles. The best range to release a higher percentage of fat to be utilized for energy has been found to occur between 60%-70% of a person’s VO2 max. At higher intensities, the ratio of fat utilized decreases, thus exercise is termed “anaerobic” because oxygen transport decreases. However, more calories are burned, and this is still a good thing as far as having a positive effect on blood sugar and insulin delivery to the cells.
So, moderate-intensity exercise (you can use VO2 max, or use the “talk test” to determine if you can breathe and talk at the same time, but not do both easily, which should put you in the correct range) is most beneficial for fat-burning, but in truth, even lower-intensity exercise, if performed consistently and for long enough duration (starting with bouts of 10 minute sessions, eventually adding up to 30 total minutes per day, most days of the week or 150 minutes total per week) can have a positive effect on cell metabolism and its sensitivity to insulin. Anyone can decrease his or her chances of getting type 2 diabetes by starting to walk, no matter what age, risk factor, weight, or waist circumference. The goal would be to increase exercise intensity, even increasing to high-intensity, or incorporating high intensity in between bouts of moderate exercise. “Interval training” or “HIIT” (high-intensity interval training) has become very popular and is great for increasing stamina, endurance and strength while allowing the body to recover.
Resistance training is also great for anyone who is at risk for or has type 2 diabetes because of the above-mentioned effect of muscle contraction on blood glucose uptake (effects on stabilizing blood-sugar levels can last for several hours after exercise).
So if you are at risk for diabetes, please get your blood sugar checked and then check with your health-care provider about what type of activity program would be right for you. If you get started now, you can decrease your risk by half or more. If you have already been diagnosed, managing it will be much easier. Either way, using exercise along with a healthful diet as your best weapons – you can battle the trend, and have a positive effect on the grim statistics.