Feet on the floor BG impact

That was lucky for you! :smiling_face_with_three_hearts: I usually react w/ FOTF every time I wake up, whether 4am, 5am or 8am. I’d have 3 spikes if that happened! :frowning:


Knowing my luck it will probably be the other way around next time! So unpredictable :sweat_smile:

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I currently bolus 0.5 units 10 mins before I get up from the bed and this seem to do the trick to stop the rise. I’m curious whether I need to do this bolus once I have control iq (it’s coming this year). Anyone know whether the auto control iq adjustment is quick enough to curb a rising FOTF effect?

Well, in one sense, no it won’t be, because it can’t.

My reasoning here is that C-IQ works using the results from your CGM. The CGM results are from your interstitial fluid, not your blood glucose (BG). So a CGM glucose is expected to trail the BG by some amount. The estimate which I think is most frequently quoted is “about 15 minutes” lag behind your BG.

So, while the C-IQ will eventually respond to the rise in your BG, my guess is that you’ll see some lag before it does that.

How you deal with that will depend on how much lag you actually experience and how much it bothers you. Those are things you won’t actually notice until you actually get to use C-IQ, no? :man_shrugging:

C-IQ does best, in my opinion, when dealing with BG that does not change quickly. If your BG rises quickly (“spikes”), C-IQ will be playing catch-up. If you know ahead of time your BG will spike, then I think you are still better off dealing with it yourself.

But again, ultimately you are the one who will have to decide what to do based on your own experience.


I’m so confused about the apparent delay between the sensor reading and the actual BG. In this thread I raised earlier this year, some people pointed out there is no delay.

And on the surface, this is what I have been seeing because when I inject insulin, it takes exactly 20 minutes on my Dexcom before I see the arrows start trending down. If there was a delay, I would expect to see the arrows trending down 15-20 mins after the initial 20 min wait.

If this was the case, wouldn’t control iq detect a rising BG in pretty much real time?

Frankly, I don’t know how much “delay” there is between your CGM glucose and a real-time BG. Because of the constant talk about the difference between interstitial glucose and BG, I am sure there is some difference. But how much? Beats me.

But even if there were no delay, C-IQ would still only start to treat your Feet On The Floor BG increase once it was detected. So there would still be whatever delay you experience for insulin absorption.

Whether that matters or not is ultimately up to you. Do you pre-bolus before a meal? If so, why? If you want to significantly mitigate whatever BG increase you experience from FOTF then I think you would need to pre-bolus for it.

If you are OK with your BG going up from FOTF but then later coming back down as C-IQ reacts to it, then just letting C-IQ handling it may be the way you want to go.


Thanks your explanation does make sense.

Which also leads me to think, doesn’t that apply to all bg rises regardless of whether it’s from FOTF? Control iq will always be lagging behind the actual rise.

Yes. But I don’t see any way around that which I would currently be comfortable with.

Whatever the C-IQ algorithm is, it is based on observing and then responding to your CGM glucose values. It can’t predict the future. At best it can, in some limited cases, guess about future BG. I think that is currently limited to extrapolating a rising/falling BG trend.

That’s why you still would most likely be expected to (pre?)bolus for your meals/carbs and events like FOTF. But nothing requires you to do so. You could just leave everything to C-IQ.

However, given the tight time-in-range goals commonly manifested by the folks who post on this forum, I would expect they would rather intervene to mitigate spikes when they can.

But ultimately it is up to the person using the pump to decide how they want to use it.

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I really think that predawn phenomena and feet on the floor syndrome are the same thing.
It’s your body getting ready for being awake and active.
Some of us experience it just before waking up and in some of us it doesn’t kick in till a

I think they are similar but not the same. The reason I say this is FOTF for me only happens when I stand up and get off my bed. It doesn’t happen at a specific time. I can lay in bed all morning and no effect on my sugar… until I stand up.

The DP I understand happen roughly at the same time every day.

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I also experience FOTF once I’m actually out of bed. It will happen if I get out of bed at 7am or noon. It’s not the time of day, it’s actually waking up and moving about that triggers it. I can’t control it by changing the basal rates in my pump unless I want to force myself to get up at the same time every day.