Hi Jayne, it’s great that you’re being so active and noticing benefits for your blood glucose levels (BGLs).

Balancing insulin, food and exercise can sometimes be a juggling act. While we can’t give you specific advice about your insulin doses, there are a number of things that you might need to think about.

Firstly, some people find that exercise can raise BGLs for short periods of time. This is because of the effects of some of the body’s hormones that rise during exercise.  However BGLs will usually fall later because exercise makes your insulin work better. 

If you don’t have enough insulin in your body, this can also make BGLs go too high.  This can happen if your previous insulin dose (eg. overnight insulin) is starting to run out.  As we don’t know what insulin you’re taking and at what time in the evening, it’s hard to tell if this is the problem.  Also, if your insulin doses are not matched properly to your food, exercise and what your body needs, sometimes BGLs can be high. If this is the cause of your high BGLs, the timing and amount of your morning insulin doses may need to be adjusted by your diabetes team.

It’s also important to think about any extra carbohydrate foods that you might be eating or drinking while being active. Some people find that they need to top up with extra carbohydrates (eg. juice) for exercise. A general guideline is about one extra serve or exchange for every 30-40 minutes of exercise, however this is very individual and depends on things such as BGL before activity and how long the activity lasts. If you have more carbohydrate than you need for the activity, this can also cause BGLs to be high afterwards.

Everybody with diabetes is different and reacts differently. You may notice changes in your BGLs at different times of the day. This can be because of the way different insulins work at different times of the day, eating patterns, the rate your body is growing and varying activity levels. 

When you have diabetes, it’s a good idea to look for patterns in your BGLs. It’s great that you’re doing this already and it’s really important that you discuss this with your diabetes team, including your doctor, educator and dietitian.  They can help you to adjust your insulin doses and food to help you get BGLs mostly within the normal range while you’re swimming.