Can Exercise Make My Blood Glucose Go Up?

Can Exercise Make My Blood Glucose Go Up?

Most of us with type 1 diabetes have been taught that exercise will make our blood glucose go down. This is true, if you do any type of exercise for long enough then your blood glucose levels will go down but as ever in type 1 diabetes things are never quite that simple…..

Some types of exercise will typically cause blood glucose levels to rise and others will make it fall. The rate at which blood glucose levels rise or fall during exercise is determined by how intense the exercise is. You would be forgiven for thinking that the most intense exercises, like weight lifting, high jump or sprinting would cause blood glucose levels to fall very quickly, but what we see in reality is that these types of exercise make blood glucose levels rise for most of us.

We also see that exercises and activities that are performed at a constant work-rate make our blood glucose levels fall and usually this happens pretty quickly. Think about it what happens when you go shopping, clean the car, mow the grass, do some repairs to the house or some decorating? Most of the time your blood glucose drops quickly. We see the same thing happening during exercises that are said to be aerobic; this includes things like cycling, swimming, jogging, rowing etc.

At the risk of getting into the science here exercises and activities that are of high intensity and short duration are anaerobic exercises and these cause our bodies to produce adrenaline and another type of chemical called catecholamines and these make us resistant to insulin. Think back to the days when we would need to run way from a predator like a lion or a bear we could not afford for their blood glucose level’s to fall, this is even true for people without diabetes, so our bodies produce chemicals that counteract the effect of insulin. This makes our blood glucose levels rise.

When we perform exercise or activity at a constant work rate we are said to be performing aerobically. Human’s are exceptional at performing aerobic exercise and we are very efficient at burning the the energy we get from food (energy) in our bodies during this type of exercise. Our incredibly efficiency in burning energy means that this type of exercise typically makes blood glucose levels fall during this type of exercise for people with type 1 diabetes.

It is important that people with diabetes exercise because it seems to reduce the risk of developing complications by lowering blood pressure, improving cardio-vascular health and lowering lipids (including cholesterol). The good news is that it is possible to perform all types of exercise with type 1 diabetes and with some help on the tools and techniques that you can use to manage your blood glucose levels you can exercise and perform physical activity of your choice at the level you choose.

They say a picture paints a thousand words and in this case that is certainly true, download this PDF for a quick reminder of how different types of exercise can affect your blood glucose levels. In a later session we will talk about how you can use this as part of your blood glucose management strategy during exercise.