Post exercise lows

We don’t have them too often, in great part because my son’s most intense exercise is swimming, where he constantly has to replace sugars. But we run into them in some circumstances, such as when he plays an intense soccer game as a field player with no subbing. And, periodically, it catches us badly because we forgot to make provisions for it.

Like last night, for instance. My son played a long soccer game. Because of a scheduling error, we did not have post-exercise carbs we could eat right afterwards. Then he had a hormone peak so could not eat for 2 hours. By then it was 8:00pm, just time for dinner and bed. Then he was low until 3:00am, having to eat 50 grams of carbs over 6 hours. Without a Dexcom it would have been really dangerous.

Our normal strategy is:

  • take some carbs right after sports

  • have a big carby meal shortly afterwards

  • underdose next meal bolus

We try to avoid cutting basal, because we pay for it 8 hours later.

What do you do to manage your post-exercise lows?

[EDIT] Forgot to mention: our basal is MDI. Chris’s post is reminding me to mention it.

Michel, prior to pumping we were dialing in, but never perfected how to manage soccer with MDI. Now that we pump, we lower basal prior to the event (usually an hour before, but sometimes longer) trying to get an upward trend in bg. If we don’t have an upward trend prior to the game starting, we add a few carbs to nudge it in the right direction. Then during the event we test and add insulin to keep it below 180. At the end of the event we restore the basal and dose to the pre-game baseline if it was above 130. By this I mean if the baseline at the start of the game was 160 we would dose the 160 down to 120, but we wouldn’t dose the 250 peak that occurred from exercise. Using this approach we don’t often have lows following sports unless we mis-dose the next meal which happens from time to time since we are working on what the cut factor is based on trying to match the effort extended.

This works for us for baseball, which often takes two+ hours to play with periods of intense exertion, and since my son catches most of the time, also involves squatting for at least half of the time. On tournament weekends we might play 4-6 games, so 8-12 hours of exertion.

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When was on MDI if I was active for 2 or more hours during the day (hiking or skiing or dancing) I would decrease my Levemir at bedtime by 0.5 to 2 units. If I was really sitting around all day due to illness, injury or sloth, I would bump it up 0.5-1 unit. I took 7 units of Levemir at 7am and 7pm. It only lasted about 12 hrs in me because 14 units is less than 0.2 units/kg for me (I’m 6 ft tall and sensitive to insulin). Anyhow, that worked quite well for me. Now on the pump I do temp basals the same way at bedtime.


@PegE, what exactly is the 0.2 units/kg rule? I know this is what you start new patients on levemir – what impact does it have on insulin diffusion speed?

not sure this is going to be useful, but I use Afrezza! :grinning: Tresiba keeps me mostly flat during exercise, I can monitor my CGM and if I start going slowly down, I supplement.
Post exercise I puff as needed to recover all the carbs I need, there is no adrenaline or other hormone that can resist the power of Afrezza. And I am talking being able to eat carbs immediately after an all-out 70 minutes Z5 sprint triathlon. Its really awesome.
Ok, back to your current scenario, while not on Afrezza and only MDI I had a similar approach. 4U immediately after exercise, wait 30 minutes, eat ~80Gch. Then back to low carbs. not really great, but I preferred that and not the risk of a severe low at night.

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I was just referring to that at low doses it doesn’t last as long as it does in higher doses.

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Smaller doses deplete quicker than bigger ones. For me, I get only 12 hours.

Insulin detemir is a soluble, long-acting basal human insulin analog with a relatively flat action profile. The mean duration of action of insulin detemir ranged from 5.7 hours at the lowest dose to 23.2 hours at the highest dose (sampling period 24 hours).

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OK. Now I see that lowest unit/kg amount in the diffusion rate curve is 0.2 u/kg.

Did you do anything beyond basal adjustments? Food, M.O. or ?

Or now?

Gus, for my information, what kind of a training session did you run prior to the 4u and the 80Gch?

It could have been a run, bike or swim. I would go with 4U of novolog regardless, wait, then eat the carbs. And then I would correct based on the CGM readings, either eating a bit more, or injecting a bit more of insulin. The key part was to minimize the IOB before going to bed.

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When I was on MDI I got a lot of help from the RapidCalc insulin calculator app for dosing humalog. It has a feature that calculates a decrease in the recommended humalog dose when you are planning to exercise within 2 hours of the humalog injection. The amount it subtracts is based on the duration and intensity, which are easily entered. That worked most of the time for me. Now that I am on the pump, I usually do a 30-120 minute temp basal of zero, started ideally about 15min to 1/2 hour before exercise, and completed 15-30min before I stop exercising. Afterward I take 1-2units, because as soon as I stop, my BG goes up, so now I dose preemptively for that. That’s just me. I know it sounds like a weird plan but it seems to keep my BG in target when I am exercising and after. This weekend I’m going to contra dance camp and I will do 24hr temp basals at about 60-80% depending on how much I am dancing and how much I am eating. I’ll also decrease my boluses a little bit. Probably very unscientifically. The CGM helps and also more frequent BGs because of lag time with the CGM sometimes.

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That doesn’t sound weird at all. That sounds like a very smart process.

i do the exact same thing. but b/c i swim, i must detach from my pump, and i cannot use a temp basal while exercising. so before i jump into the pool, i do 2.5 hours of 0% TB (no bolus IOB) and when i am in the pool, swimming, i dont crash. but as soon as i get up to the locker room, i reattach to my pump and bolus manually (not using the WIZARD) and “replace” a percentage of the basal i was missing for the time that i was not getting any.(and i swim for 2 hours, so its 4.5 hours off of all insulin)

Wow! 4 hrs off insulin and your bg doesn’t go up until after you stop swimming?

nope. so long as i do the bolus the minute i get out of the pool. eric taught me this trick and it works like a charm. i just have to bolus big. then my BGs stay down.