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High glucose after long run

Discussion in 'Fitness, Exercise and Sport' started by Roggg, May 23, 2021.

  1. Roggg

    Roggg Type 2 · Well-Known Member

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    I know glucose can go up during exercise, but I tested this morning about 30 minutes after finishing an hour long run, and my BG is at 8. That's the highest number I've seen on a meter since...well, not sure. It's been a while. It's perplexing, and slightly concerning, but I guess I'll just check again in an hour. I really should get a cgm and get a better picture of what really happens when I run fasted.
  2. Ronancastled

    Ronancastled Type 2 · Well-Known Member

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    Similar experiences online.
    Here's a non-diabetic doctor who trialled a CGM.

    Body has to fuel itself, liver releases glucose from fat stores.
    Natural process, nothing to worry about.
    Less aggressive exercise produces lower spikes.
    • Agree Agree x 1
  3. catinahat

    catinahat Type 2 · Well-Known Member

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    The higher numbers you are seeing are from your liver releasing stored glucose to fuel your run. It was already in you, it's just moved from your liver where you can't see it to your blood where you can. So rather than be concerned I would view it as proof that my exercise is paying dividends by reducing my stored glucose
    • Agree Agree x 2
    • Like Like x 1
  4. In Response

    In Response Type 1 · Well-Known Member

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    For me, it depends on the type of exercise. I rarely run but I often cycle and the intensity and type of workout affects my levels differently
    - a long hard sprint will cause a drop
    - multiple short sprints (intervals) will cause a rise. This is the same as the interval training in the tweeter article mentioned above.
    - a pootle with my mates along the flat will have no impact
    - a slog uphill in the rain, against the wind will cause a rise

    but any rise will be short term. It will lead to a lower level over the next 24 hours.
  5. LittleGreyCat

    LittleGreyCat Type 2 · Well-Known Member

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    The issue that I have is that when I am properly in ketosis and using ketones for energy my liver still dumps glucose into my blood stream to supply energy needs that my muscles don't have.

    I assume that it gets slowly reclaimed by the liver once my BG starts to fall again.
  6. batchu

    batchu Prediabetes · Newbie

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    I suspect i have insulin resistance. My fasting BS is ok. However my HbA1c exceeds 10 about one hour after eating high carb diet. Normally i take a light walk for about 15min. and it drops to 6.5. What i can not understand is, how the glucose in the blood stream is used by the muscle cells. My understanding is insulin pushes glucose in the blood to the cells. I do not see why this process depends on depletion of glucose already available in the muscle cells. Can anyone explain?
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