Impact of different exercise types on blood glucose levels

It’s a cold Monday evening, you’ve managed to convince yourself to do some exercise to start the week well. All of your equipment is packed and you’re ready with fast acting glucose for the low blood sugar levels that exercise will bring on. You complete your workout, and are currently feeling good about your achievement. Blood glucose level is checked and the results show your current levels are.. high!?!? The unpredictability of diabetes continues and there is now confusion around what actions to take.

The reality of this situation is commonplace, and this comes with good reason.

Not all exercise types will impact blood glucose levels in the same way!

The type, intensity and duration of physical activity will impact insulin sensitivity and glucose metabolism. This article will cover 5 different types of exercise and the likely outcome these will have on blood sugar levels.

1. Aerobic Exercise e.g. brisk walking, swimming, cycling

This is also known as ‘cardio’. It generally decreases blood glucose.

2. Resistance Training e.g. weight training

This type of exercise keeps blood glucose more stable than other types. It may however increase blood glucose levels.

3. Short anaerobic exercise e.g. sprinting, jumping

This will generally increase blood glucose levels.

4. High Intensity Interval Training (HIIT) e.g. circuit training, football, tennis

HIIT is a type of exercise that alternates short periods of intense anaerobic exercise with less intense recovery periods. This exercise type will decrease blood glucose but at a weaker rate than aerobic exercise.

5. Long duration exercise e.g. long distance running, hiking or skiing for a long period

This type of exercise increases blood glucose utilisation, and therefore may increase the potential of hypoglycaemia.

To increase chances of success with blood glucose management it is worthwhile considering the following:

• The type, duration and intensity of exercise
• Taking into consideration individual factors – e.g. an active person with T1D will have an overall lower glucose level than a sedentary counterpart
• Monitoring blood glucose frequently
• Adjust carbohydrate intake before, during and after exercise
• Adjust insulin dosage (both basal and bolus if necessary)

Before starting any new exercise regime discuss it with your healthcare professional. In particular discuss with them how to adjust your pre exercise insulin or diabetes tablets.