Diabetes is a metabolic disorder that affects our insulin secretion, action or both. There are three types of diabetes with only two regularly making the news.
Type I diabetes is often referred to as insulin dependent, child on-set or juvenile diabetes. Type I diabetes accounts for 5-10% of the diagnosed cases in Europe/North America. Type I is referred to as insulin dependent as the body does not make the amount of insulin it needs to help control glucose levels in the body. This causes the body to go into hyperglycaemia, which is where our glucose levels are elevated as we are unable to utilise this glucose.
Type II diabetes is referred to as non-insulin dependent and makes up 85% of all cases diagnosed in Europe/North America. This is the most common type of diabetes for obese and overweight patients. The body produces enough insulin however the body’s cells designed to regulate the uptake of glucose become resistant, meaning the body produces more insulin. Type I diabetes was common in 30-50 years of age, now it is being diagnosed in more 20 years old and younger.
The third type and one not often hears of is Secondary diabetes, this occurs through either haptic cirrhosis, pancreatic damage or endocrine related disease.
Testing for Diabetes
Two tests occur to determine if somebody has diabetes, these are a fasting glucose test (8-12 hours after last meal) and Oral Glucose Tolerance Test. If blood glucose falls into a band of ranges you may have diabetes.
|Fasting Test||Post Glucose Load||Diagnosis|
|< 6.1 mmol/L||< 7.8 mmol/L||Normal|
|6.1 – 6.99 mmol/L||7.8 – 11.09||Impaired fasting glucose|
|>7.1 mmol/L||>11.10 mmol/L||Diabetes|
Why is exercise beneficial?
Exercise is beneficial to diabetes as the changes that occur at a cellular level and in the muscles all assist against insulin resistance. Resistance training is beneficial in that it can assist in minimising the risk of exercise induced hypoglycaemia, particularly to those who are diagnosed with type 1 diabetes. Resistance training helps people diagnosed with type 2 diabetes by improving an individuals glycemic control, insulin resistance, blood pressure, strength and lean body mass. Cardiovascular training assists by reducing A1C, triglycerides, blood pressure and insulin resistance. If you are able to high intensity interval training also ha benefits in that it improves the muscle oxidative capacity, insulin sensitivity and glycemic control.
Post exercise session, insulin action is improved for type 1 (2 hours) and type 2 (48 hours) diabetes, meaning glucose uptake is elevated improving muscle glycogen repletion in the muscles. For shorter sessions, 20 minutes a near-maximal effort, insulin has seen to be improved for 24 hours.
Exercise is more beneficial to improving your insulin sensitivity than calorie restriction. Exercise increases the GLUT 4 transporter, this is important in drawing blood glucose into the muscle cells. If you had a high fasting glucose result, the amount of weight you lose is proportional to returning your glucose levels back to normal
What exercise is deemed appropriate? You should perform a mixture of both cardiovascular and resistance training. As always, start where you feel comfortable, this could be walking to begin with. The government guidelines set 150 minutes of moderate physical activity a week AND two resistance training sessions. Resistance training is very beneficial to those with diabetes as it reduces plasma free fatty acids, reduces arterial blood pressure and lowers the average blood glucose levels.
If you have diabetes and are looking to start an exercise regime it is best to talk to your doctor before you do.
Prior to an exercise session you should monitor your blood glucose levels not only before the session but also several hours post exercise, this can prevent hypo and hyperglycemia episodes.
Further precautions should be taken, you should make sure you have plenty of water as you are likely be dehydrated quicker than someone without diabetes, make sure you have food available to eat during and immediately post workout and make sure you have suitable footwear.
Exercise must form part of an appropriate management strategy for anyone with diabetes. If you are exercising alone, make sure you let gym staff know you have diabetes and also wear a medical bracelet.
The following picture shows exercise recommendations from the American Diabetes Association for people with diabetes. One consideration, if performing resistance training and cardiovascular training in the same session, you should look to perform the resistance exercises first. Carrying out resistance exercise first results in less hypoglycaemia, compared to if you carried out cardiovascular exercise first.
For more reading on the Physical Activity/Exercise and Diabetes: A Position Statement of the American Diabetes Association click here