World 12-4
Insulin on Board (IOB)
The Secret Stash
Basal and Bolus
Basal and bolus insulins are different but the same.
Of course, they are the same in that they are insulin!
But they are for different BGL-managing purposes.
Basal insulin is always on board the body. Because the liver ‘drips’ out glucose in the background. I inject Basal 2x a day (morning/evening) personally, though not everyone does. The only time I adjust morning Basal for exercise is when I know I’m doing a big hike that day.
Bolus insulin is for the meals and lasts for a few hours, I’ve found. When it comes to exercise, I either make an adjustment by:
- reducing bolus, or
- increasing food/carbs
My Own Estimate
I’ve tried to work out a rough model of how the Bolus insulin I use actually works in my body. (This book goes into a few models).
Knowing how long the insulin lasts, and how much is left helps me with making decisions in advance.
For example, if I know my Bolus injection is basically finished, I don’t worry about eating lots of fruit for exercise. But if I injected 1 hour ago, and I work out that there’s a high percentage left of IOB, I can estimate how many carbs to eat.
I’ll go more into how I worked out my personal model on the Resources page.