Managing diabetes is a multi-faceted challenge that ranges from nutrition, exercise, awareness of hypoglycemia training, and of course self-management education. Exercise is a phenomenal lifestyle tool that can effectively prevent the onset of type 2 diabetes and also for the direct management of both type 1 and type 2 diabetes. Type 1 diabetes only effects 5-10% of those diagnosed with diabetes in the United States and is often times referred to as insulin-dependent diabetes, or, juvenile onset diabetes. Type 1 diabetes, or T1D, is an autoimmune destruction of the Beta cells in the pancreas that are in charge of insulin production and in children and adolescents these B cells are almost completely destroyed, thus, leaving these individuals to be completely insulin dependent. This process is incredibly rapid in infants and children; however, it is relatively slower in adults. Interestingly, African Americans and Asians afflicted with T1D appear to be caused by a hereditary disorder and not an autoimmune disorder, although the reasoning for this is still unclear. The other 90-95% of those diagnosed with diabetes suffers from type 2 diabetes, T2D, or otherwise known as non-insulin dependent or adult-onset diabetes. These individuals experience insulin resistance which can range from pre-dominate insulin resistance with insulin deficiency to insulin resistance with insulin secretory defect. Most people who have T2D do not require insulin treatment early on and even often times have a substantial delay in being diagnosed with type 2 diabetes because hyperglycemia is a gradual development, however, it should be noted that a staggering 50% of these individuals eventually become fully insulin dependent so that they can maintain metabolic control. Although the complete genetics for this disease are not completely understood it is known that there is a very strong genetic predisposition for T2D and certain rick factors are also known to increase the chances of developing T2D such as a sedentary lifestyle, obesity, dyslipidemia, hypertension, and age. It is very important to note that most individuals who have signs and symptoms of pre-diabetes can treat and even possibly prevent T2D with exercise management.
In 2004 there was a statement released by the American Diabetes Association, ADA, recommending that before an individual increases their patterns of physical activity or beginning an exercise program that patients need to undergo a detailed medical evaluation in which they are screened for risk of renal, ocular, and cardiovascular disease. The graded exercise testing, GXT, is the currently accepted method of guidelines before initiating an exercise prescription for individuals that are 35 years of age and older, those who have had T2D for more than 10 years, and for those have had T1D for more than 15 years. Currently, the most widely used and accepted method of exercise testing in adults and children are the treadmill and bicycle ergometer testing. Out of the two of these the treadmill is preferred because it more closely resembles that of activities of daily living, ADL’s, such as walking. The treadmill also causes the patient to utilize more total muscle mass thus resulting in greater maximal oxygen consumption which will allow for a greater understanding of blood glucose levels with increased V02 max levels. The bicycle may be preferred over the treadmill if the patient has difficulty with balance or if cost and space are a concern as the bicycle tends to be cheaper and require less space. These same modes are used with children as well; however, since children tend to need to be motivated and surrounded with upbeat positivity the treadmill is preferred again over the bicycle. This method is chosen for a multitude of reasons, some of which include the fact that children are inherently more immature and so it becomes more of a daunting task to have them sit on a bicycle and meet the requirements of making a predetermined amount of revolutions on the bicycle in a given amount of time, also, the seat height, size of bicycle, and the pedal crank length can also be limiting factors. Whereas on the treadmill the child is only required to maintain a consistent pace on conveyer belt which will in turn allow for a much more consistent reading of V02 max without the struggle of trying to ask and encourage a child to make maximal effort on a bicycle without quitting when approaching fatigue.
In order to achieve the highest level of success in health and well-being in regards to the benefits of exercise, the programming must be diverse in nature and should include multiple different components such as and not limited to cardiorespiratory fitness, muscular fitness, and of course body composition. Children are recommended to perform at least 60min of exercise per day and the exercises, again, should be varied and range from aerobic activities at least 3 days a week, strength training 3 days a week, and also bone strengthening at least 3 days a week. In a generalized since, adults should follow almost identical protocols, however, adults should aim for 150 minutes a week of moderate-intensity physical activity or 75 minutes if vigorous-intensity to see true health benefits of exercising. Again, the programming needs to be diverse and focus on multiple areas of fitness such as the before mentioned with strength training and cardiorespiratory training. For adults, there are a few other considerations to keep in mind when discussing an exercise program. For instance, for more extensive health benefits adults can start or work up to 300minutes of moderate-intensity exercise a day or 150 minutes a day of vigorous-intensity exercise. It is of paramount importance for adults to focus on resistance training at least 3 days a week as science has shown the acute physical fitness and muscular endurance helps with insulin uptake and decreases insulin resistance. As always, for those individuals whom are pre-diabetic or are diabetic it is strongly recommended that an exercise physiologist is a part of the developing of the exercise prescription. Also, with every exercise prescription it is critical to remember that every conditioning phase should start with a warm-up and end with a cool-down. While warm-ups and cool-downs should consist of low-intensity large muscle group activities and stretching, the conditioning phase should focus on improving the before mentioned areas of cardiorespiratory fitness and local muscle fitness with proper programming. When designing an exercise prescription it is important to remember that both upper extremities and lower extremities need and should be involved and there also needs to be clear details as to frequency, intensity, specificity, and of course mode of progression for the said exercise program. Whenever a program is being designed for cardiorespiratory fitness it is critical to cycle through and implement both upper and lower extremities in such activities as walking, jogging, and swimming. By ensuring that both upper and lower extremities are being worked you are insuring proper circulation, yields for higher V02 max, and of course creating a larger work load can and will produce higher results in most cases.
For many years the importance of resistance training was overlooked by the importance of cardiorespiratory fitness and it was often times over looked as the benefits of resistance training had not been studied in the same amount of detail, however, now the importance of resistance training is becoming more prevalent and widely understood. One of the biggest roles in resistance training is to help build muscular strength and endurance to ensure the patients are able to carry out activities of daily living, ADL’s. Many people afflicted with diabetes do not know where to begin when it comes to exercise and are often times mislead that they should avoid physical exercise in fear of interfering with insulin uptake and release and so these individuals begin to suffer with macular degeneration, thus, the importance of resistance training. There are numerous benefits associated with strength training such as decreased mortality rates, decreased insulin resistance, reduced blood pressure, improved lipid profiles, reduced abdominal visceral fat, and overall improved homeostasis. There have been multiple large scale studies done on patients who are at a ‘high risk’ with pre-diabetes and through effective exercise and diet modifications have been able to drastically reduce the progression of diabetes. These modifications were generalized across both gender and race and were proven to be more effective in controlling and preventing diabetes than treatment with insulin regulating drugs such Biguanida.
Individuals with type 1 diabetes are able and encouraged to perform all levels of physical activity ranging from leisure activities, recreational sports, and even competitive professional performance so long as the patient does not have complications and they have optimal glucose control. It is of paramount importance that these individuals adjust and monitor their insulin and nutritional needs because exercise increases insulin sensitivity. In response to all physical activity, these individuals need to collect self-monitored blood glucose data and should also work in conjunction with medical staff to ensure not only their safety but also their success in improving performance. For those that have T1D, hyperglycemia and Ketosis can be made worse through exercise if this person has be deprived of insulin for 12-48 hours. Originally, it was thought that these individuals that have T1D should avoid physical activity if their fasting blood glucose was more than 250mg/dL in the presence of Ketosis, however, in the absence of Ketosis exercise should be performed with caution. It is now believed that if an individual feels well and there is hyperglycemia without Ketosis that exercise is not precluded as long this individual follows the mentioned guidelines of nutrition and glucose monitoring. For those afflicted by type 2 diabetes it is recommended to follow the same guidelines of exercise with 150 minutes of physical activity per day as long as they feel well, are properly hydrated, and are not Ketotic. It should also be stated that for these same individuals that the recommendation to avoid physical activity with blood glucose more than 300mg/dL, even in absence of Ketosis, is probably overly cautious, especially after meals at lunch and dinner. The risk of exercise induced hypoglycemia increases with prolonged exercise and it is recommended that individual blood glucose levels are monitored before exercise and carbohydrates are consumed if glucose levels are lower than 100md/dL and as needed throughout exercise. In both healthy and insulin-resistant skeletal muscle, insulin stimulated glucose disposal increases with acute exercise; therefore, physical activity can induce hypoglycemia if medication or carbohydrate consumption is inadequately adjusted.
Exercise may very well be the most important and also underrated tool for managing a healthy lifestyle with either type of diabetes. Of course, nutrition is side by side with this topic; however, the dramatic influence that exercise has on managing diabetes can no longer be ignored or overlooked. With many, many studies being performed on both pre-diabetics and diabetics it has been proven that effective lifestyle management with exercise can and will prevent the onset of type 2 diabetes and is also the most powerful tool in managing type 1 diabetes. Cardiorespiratory fitness and muscular fitness have been proven to help reduce and even eliminate insulin resistance while also improving the quality of life by improving an individual’s ability to carry out activities of daily living, lowering blood pressure, and even aiding in the reduction of visceral fat and the chances of cardiovascular disease. For too long the importance of physical exercise has been down played and sadly those who are afflicted with diseases such as diabetes are the ones who suffer the most. Many people are told that it is their genetics or their eating habits and that there isn’t really anything that they can do to remedy the situation so a lot of people just continue on with their daily living habits; completely unaware and undereducated in ways of how physical exercise can dramatically alter the course of the disease and even possibly prevent diabetes. Exercise education needs to be mandated as part of treatment for those who suffer with diabetes and it needs to be more widely accepted as a way to both prevent and manage the disease rather than immediately going to drug treatments whenever it is at all possible.
References
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