A Single Bout of HIIT Reduces Awareness of Subsequent Hypoglycemia

“A single [High-Intensity Interval Training (HIIT)] session rapidly reduces awareness of subsequent hypoglycemia in patients with type 1 diabetes and [Normal Awareness of Hypoglycemia (NAH)], but not in patients with [Impaired Awareness of Hypoglycemia (IAH)], and attenuates hypoglycemia-induced cognitive dysfunction.”


That was a great read. I am not quite sure what to think of the conclusion, though.

The way I read it:

  • awareness of hypoglycemia goes down after HIIT. That is BAD.

  • but symptoms of hypoglycemia go down too. That is GOOD.

I know I am simple-minded. What do you read out of this? What are your practical conclusions?

My son does some HIIT btw when he does not have time to go to swim practice.

I just read it too. Didn’t see much in terms of medical explanation or details of the experiment.

After high intensity interval training they check your awareness of a hypo. They suggest that after the interval you are not as aware of your hypo. But they don’t specify how long after, or what they are calling “subsequent hypos”.

If you think about it, imagine doing sprint ladders or pyramids. Afterward, you are totally depleted and exhausted. You can barely walk. At times like this, yes I agree, I would have no idea if my BG was low, because I can barely stand up. But after I have recovered, then I become more aware again.

So the question I have is - are “subsequent hypos” immediately following the training, or days later?

Depends on what they are saying. I do high intensity stuff about twice a week, but I still recognize a low when I am resting.

I am sometimes skeptical of studies because of sentences like this:
"The role of exercise-induced lactate in mediating these effects, potentially serving as an alternative fuel for the brain, should be further explored."
It makes me wonder, did they do this just to get more funding? I don’t know it that is the case, but I think it’s a fair question.

Anyway, would love to hear some explanation of this. Is there a doctor anywhere on this forum? :slight_smile:


It looks like Bastiaan de Galan is a younger MD-PhD from the Netherlands studying things that affect diabetics. His group studies jet injection techniques and brain changes due to diabetes.

All studies will include a section for future investigation, it is just usually a little more in-depth than asking for further research in the area their group is expert in. Also, they usually cloak the we should do more of what we are good at in a little more word-smithing. But considering that they are writing in English, and it isn’t their native tongue, and the Dutch are pretty matter of fact, I guess it doesn’t come off well.

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it seems to me that secretly they’re most intrigued by lactate as an alternative fuel source. The HIIT seems like a way to investigate this.

I would say the takeaway is: glance at your Dexcom a little more after HIIT? Just something to be aware of?

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I think the lactate part is due to how they built their test hypothesis, they seem to have started from it::

"HIIT acutely increases plasma lactate levels. This may be important, since administration of lactate during hypoglycemia suppresses symptoms and counterregulation, whilst preserving cognitive function. We tested the hypothesis that HIIT acutely reduces awareness of hypoglycemia and attenuates hypoglycemia-induced cognitive dysfunction. "

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Lactate is already used as a fuel source by mitochondria. There is a special transporter that allows lactate to be transported to different muscle fibers. Some of the important adaptations that take place due to training are an increase in the mitochondrial mass, and an increase in the quantity of the transporters.

The problem is making it more sustainable. That’s why you train.