I hope the following discussion is also interesting for pumpers. It shows a potential new feature and I would like to hear your feedback.
The Insulin On Board (IOB) is a guestimation how many units of insulin are still active from the last shot. Foremost it is a reminder that additional physical activity might amplify these remaining units (risk of lows). In addition to that it helps to prevent the overcorrection of a higher blood glucose.
With physical activity I see the need for an additional reminder: Sensitivity On Board (SOB). After sports the sensitivity to insulin is increased for several hours. The muscles will restore their glycogen stores and this will for sure lower the blood glucose. The timespan depends on the level of activity and individual reactions. For simplification I will adopt the workings of our Glucosurfer project but I think it can be applied to a pump too. In our diary we have four levels of activity: normal, moderate, high and maximum. Let us assume we can define the SOB timespan in minutes for every level.
Now the system would work like this:
You would work out for 1 hour and this will be documented in the diary / pump: high activity starting at time x. Associated with this high level you have defined that high activity leads to an increased sensitivity for 300 minutes (=5 hours). So for the next x+5 hours the SOB warning will be shown. It will remind you that you are now acting under the influence of physical activity that happened hours before. I am not sure if it is wise to use the information to directly reduce the I:C. Maybe the character of a warning would be more appropriate. What do you think?