Activity level, sickness and basal needs for a teenager

My son’s basal needs vary widely and quickly. Over the past few months we have found out a pattern that turns out to be reasonably repeatable. This is valuable info for us and I figure the range of numbers we found may be interesting to others as well.

The reference basal level I use is an arbitrary level that is actually rarely real, but that represents more or less the mid-point in the range of basal needs we see. This is our scale:

  • Ongoing swimming practices 3-4 days per week, plus some other miscellaneous sports (jogging etc.): -30% [It is possible that extreme swim prep before a meet might take him down even below that]

  • regular exercise and sports practices more or less daily (45 minutes or more) but no swimming: -20%

  • no exercise for 24 hours: -10%

  • no exercise for 48 hours, but vigorous daily activities: “base” basal need

  • no exercise for more than 48 hours, average daily activities: +10%

  • no exercise for more than 48 hours, little motion (such as being in a car for the whole day): +20%

  • sickness: anything up to, so far, 60% (but I have read others with much higher numbers here on our forum). Typical would be +40% (as it is today for instance).

For us, this level of exercise (and basal need) changes almost daily, particularly in winter when it is harder for us to exercise outside. Along with basal needs, correction factors also change, but to a lesser degree. Still, we find this constant change to be a significant contribution to our labors in balancing BG every day.


You all have worked really hard to “codify” @Kaelan’s current requirements! Awesome! :muscle:t3:


I’ve found pretty similar % adjustments…

I was super lazy for a week and my basal was 16u lantus and I still ran kinda high. 16 is my “lazy for 2+ days” basal.

I’ve been back running and swimming for the past week and woke up every hour the past 2 nights to my dexcom barking at me at 13u, so I will use 12 tonight. 14 has been my typical amount.

Haven’t been sick yet.