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You are here: Home / Media Resources / Articles / The Diabetes Epidemic: What we need to understand about the basic physiology of Type 1 Diabetes [article]

The Diabetes Epidemic: What we need to understand about the basic physiology of Type 1 Diabetes [article]

The physiology of Type 1 Diabetes is complex but isn't linked to the usual factors of poor diet, lack of exercise and excess body fat the way Type 2 Diabetes is. Type 1 Diabetes causes about 10% of Diabetes cases and it's exact cause is still relatively undefined.


Type 1 Diabetes represents about 10% of cases diagnosed worldwide. A lack of knowledge about the different types of Diabetes means that Type 1 Diabetes has become a disease incorrectly associated by many with poor nutrition, physical inactivity and excess body fat.  In fact, Type 1 Diabetes develops due to none of these things - however the incidence of Type 2 Diabetes has grown to epidemic proportions due to our over-indulgent and sedentary western lifestyle!


What is Type 1 Diabetes?

Type 1 Diabetes usually develops during childhood - although it can develop at any age.  A person generally has a genetic predisposition for the disease (a family history), and some kind of environmental factor must occur that ‘triggers’ it’s development. Scientists are still working to discover what that trigger is, but it could be something as simple as a virus like the common cold, or related to diet early in life. Once this trigger occurs, the individual’s own immune system begins to attack their pancreas, eventually leaving it unable to produce and release insulin. Remember that Insulin is the hormone responsible for moving glucose from our blood into our body’s cells (muscle, liver and fat cells). When no insulin is available, no glucose can get into our cells meaning glucose levels in the blood keep climbing, and the symptoms of Diabetes will appear.


What are the symptoms?

Type 1 Diabetes symptoms tend to have a rapid onset, and include excessive urination, excessive thirst, fatigue, and unexplained weight loss.  Once Type 1 Diabetes has been diagnosed, an individual will require multiple insulin injections throughout the day to keep their blood glucose at a safe level.


Does this have an effect on their ability to exercise?

In non-diabetic people the hormones insulin and glucagon work together to ensure there is always enough glucose available in the blood for our brain, as glucose is its primary fuel. This natural balancing act is essentially lost in the person with Type 1 Diabetes, as all insulin is administered externally, and can’t be reduced internally if needed.  The biggest challenge during exercise is that a pre-exercise insulin injection will keep moving your client’s glucose out of their blood and into their cells, even if the levels in the blood are getting too low.  If glucose levels fall below 4mmol/L (four is the floor), hypoglycaemia - low blood glucose levels - occurs, which can potentially lead to a coma, or even death.  


How can I stop this happening?!

Fitness professionals need to work together with their client and their client’s doctor to adjust their medication regime when starting an exercise program. There could be a need to reduce the amount of insulin injected pre-exercise, or to increase the amount of carbohydrate eaten before a session.  Extreme care needs to be taken to ensure that a client does not drop to dangerously low blood glucose levels when participating in physical activity, and trainers need to be able to recognise the signs of hypoglycaemia immediately.


Some of the signs of hypoglycaemia are:

  • Pale skin
  • Dizziness
  • Shaking
  • Fatigue
  • Anxiety


What should I do if hypoglycaemia does occur?

You should always carry some high GI foods (e.g. lollies) on you when training a Diabetic client, and they should always carry their own blood glucose monitor on them. If hypoglycaemia does develop, stop the exercise session, give your client high GI foods and water, and once they feel better and their glucose levels have come back up, they can head home – don’t let them carry on with the session. Remember to monitor them in the club until they leave, and call them later to make sure they are ok!


Initial aims when training a Type 1 Diabetic client

Your client must have good control over their glucose levels before they even think about beginning an exercise program, and while it may take a bit of trial and error while getting started, they should eventually be able to participate in any kind of exercise program they would like to.


High intensity exercise tends to prove more of a challenge for controlling glucose levels – it can even cause hyperglycaemia (high glucose levels) due to the extra glucose being released from the liver into the bloodstream. There may not be enough insulin in the body to cope with the extra glucose, and levels begin to rise.


Until you and your client have sussed out the best approach in terms of carbohydrate intake, insulin injections and how they respond to different training sessions, low to moderate intensity exercise may be the safer option.


Will exercise help control Type 1 Diabetes?

Type 1 Diabetics will always require insulin injections to control their Diabetes, however many Diabetics who exercise find that they require less insulin overall as long as they exercise regularly. 


People with Diabetes are more susceptible to high blood pressure, stroke and cardiovascular disease along with damage to their eyes, kidneys and feet if they frequently experience hyperglycaemia.  This is due to the thick blood causing damage to the smaller blood vessels in their body. 


An active lifestyle combined with a healthy balanced diet will help keep their glucose levels in the normal ‘safe’ range, lower their blood pressure and reduce cardiovascular risk factors. All which should help prevent the development of many complications. Plus – regular exercise promotes feelings of health and well being, provides many physical and psychological benefits, and may give a person with Type 1 Diabetes a sense of control over their disease, and subsequently, their life.