Insulin-on-board; the fastest way to exercise hypos
Updated: Mar 19, 2020
Impromptu bike ride with the dogs + 2U of insulin on board = mid-ride low snack. 😩 The most impactful way to avoid lows during aerobic workouts is by going into the workout with basal on board ONLY. Yesterday evening we decided to take our dogs on a spontaneous bike ride after I had just bolused for a high blood sugar. I new it was risky, especially because I didn’t have time to set my temp target 1 hr early (like I usually do). Still, I suspended my pump and off we went. Within 20 minutes my BG had dropped from ~200 mg/dL to 70mg/dL. 😬 Yikes!! I’m sharing this story because it highlights IOB as a key factor in hypos during aerobic exercise. There are two physiologic factors that contributed to my hypo; insulin stimulated AND contraction stimulated glucose uptake (independent of insulin). Unfortunately for me, the glucose I had initially intended to be transported by my bolus was taken up by skeletal muscle leaving me with excessive amounts of IOB. High amounts of blood insulin is the number one cause of hypoglycemia during exercise and to be honest... this doesn’t just apply to bolus on board. Excessive basal on board can also result in exercise lows. This is why it’s so important to set a temp basal or temp target 1-2 hrs BEFORE an aerobic workout. If you suffer from excessive lows during exercise, IOB could be your problem!