Diabetes is an insidious silent assassin that is creeping into most families lives. Around 1.7 million in Australia live with it, and 85-90 per cent of cases is type 2. Type 2 diabetes is increasing at an alarming rate with almost 300 Aussies diagnosed with diabetes each day.
Fortunately type 2 diabetes may be avoidable for much of the population. Essentially type 2 diabetes occurs when an individual's blood stream is overloaded with excessive dietary carbohydrate over several years. Ultimately, all forms of carbohydrate eaten are broken down by the digestive system to simple sugars that can be absorbed into the blood stream. The type of sugar that chiefly circulates in blood is glucose.
Glucose is also the form of carbohydrate that our trillions of tiny body cells use for energy to power the biological processes necessary for life.
However, our body's cells capability to "suck" up glucose from the blood and use it for energy is limited. Consequently, if excess carbohydrates are eaten beyond the maximal rate they can enter a cell, blood glucose progressively creeps up over time.
Critically, the pancreas, the organ that releases the hormone insulin to facilitate our cell's uptake of glucose from blood becomes desensitized to rises in blood glucose. Exacerbating the issue is the body's cells themselves also become less sensitive to insulin.
Therefore, the body's system of maintaining stable blood glucose concentration through insulin becomes almost useless and type 2 diabetes ensues. Fortunately, several lifestyle factors can be modified to ensure the body is not overloaded with glucose.
Limiting dietary carbohydrate is clearly important to prevent glucose overload. Another lifestyle factor is regular physical activity. Moving muscles during aerobic or resistance exercise increases the muscles cell's uptake of glucose by up to 5-fold.
Furthermore, increased muscle cell uptake of glucose may persist for 48 hours after exercise. Essentially exercise helps prevent diabetes and manage blood glucose in diabetics by increasing muscle cell's glucose uptake from the blood.
Aerobic exercise involves repeated and continuous movement of large muscle groups. Walking, cycling, jogging, and swimming are all examples of aerobic exercise. Research projects from several countries have shown engaging in approximately 150-300 minutes a week of moderate intensity physical activity can prevent the incidence of type 2 diabetes by up to 50% in the population studied.
Moderate intense can be gauged by practical measures, such as elevation in heart rate or the individual's rating of perceived exertion. A heart rate of 55% of your individual maximum heart rate or a rating of perceived exertion (how tough you feel exercise is) of 12-13 on a scale of 20 (20 representing the highest exertion) are good starting points to gauge moderate intensity exercise.
You should be able to engage in conversation at a moderate exercise intensity. 75 minutes a week of vigorous intensity exercise is enough exercise to significantly reduce the chances of developing type 2 diabetes or assist diabetics manage their blood glucose concentration.
Vigorous intensity exercise can be roughly determined as an exercise intensity where it is difficult to engage in conversation. Generally moderate or vigorous exercise should be spaced out with no more than two days between exercise sessions to have maximum impact on blood glucose control.
Researchers have shown that supplementing aerobic exercise with two days a week of resistance exercise provides an additional benefit un preventing diabetes and maintain blood glucose stability in diabetics. Resistance (strength) training includes exercises with free weights, weight machines, body weight, or elastic resistance bands.
Sedentary behaviour-waking behaviours with low energy expenditure (e.g., prolonged desk work, watching TV) is a significant risk factor for developing diabetes. The American Diabetes Association advise prolonged sitting should be regularly interrupted with bouts of light activity for a couple minutes every 30 min in adults with type 2 diabetes. Walking, stair climbing, body weight exercises such as star jumps, or push ups are all examples of activities that may help the body cells suck up and use blood glucose.
It is important to consult with your general practitioner to obtain medical clearance before engaging in moderate or vigorous intensity exercise. In addition, most adults with diabetes may also benefit from working with a diabetes-knowledgeable clinical exercise physiologist to formulate a safe and effective exercise training program.
Diabetes is most often accompanied by other pathologies such as obesity, hypertension, and vascular conditions that lead to stroke, heart attacks, foot ulcers, kidney failure and blindness. Clinical exercise physiologists can determine the acute complications of exercising with various pathologies and are trained to identify the most appropriate physical activities to avoid or limit in context of the individual's medical history and prescribed medication.
Both aerobic and resistance exercise can be viewed as preventative measure for type 2 diabetics and as an adjunct treatment strategy for diabetes to maintain blood glucose at a safe concentration. Move it to use it!
Brendan O'Brien (PhD) is a senior lecturer in Exercise Physiology at Federation University Australia.
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