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Low blood sugar post-workout

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  • Low blood sugar post-workout

    I've been eating strict PB for 8 weeks now, off-and-on for the last 8 months. My workouts include 20-30 miles per week of running/walking and strength training 2-3x/wk. When I started strict PB, I took it easy with the weights, stayed at maintainance until 2 weeks ago, when I began a structured program.
    I eat a good breakfast, do workouts at lunch (about 5 hours post breakfast), then eat dinner about 5 hours later- 2 meals/day. Daily carbs are well below 100g, though I haven't counted for several weeks. I've got about 20 pounds left to lose, have been doing well with my current eating strategy.

    On Saturday, I was really tired, so upped my carb intake for the day, which worked well. During today's workout, I became very shaky and fatigued and was worried that I might pass out. I am working to muscle exhaustion purposefully, and have made strength gains over the last 2 weeks, but I'm wondering if I should be taking in carbs before/during/after my workout. I did drink coconut water immediately afterward today (22g carbs), but still shaky, and had to sit in car for a while before I felt comfortable driving. I know it's because I'm glycogen-depleted, but I don't want to shortchange any gains I've made in ketoadaptability...I might just need reassurance that this is what's supposed to happen .

    Any suggestions, threads I should read, other resources? I did a search of the forum but didn't find anything that seemed to fit. Thanks for your help!
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  • #2
    I would actually test your blood sugar after because what you describe can also be related to overtraining, breathing technique, big stress response. I've felt like that from time to time and bounce back with no post-work out carbs. Can also be normal for very high level of intensity.

    I would even experience it on 250g+ carbs in the old days. About how long would you guess it took the shakiness to go away?


    • #3
      It takes about 20 minutes or so, then I feel worn out the rest of the day. I don't have any other ill effects, though, and usually sleep very well that night. I did used to experience this with HIIT stuff, but that was when I was eating lots of carbs. When I got shaky, I would stop training and eat some fruit or an energy bar. I'm ok with it taking time to recover, I just want to make sure it's okay and won't hurt my training. Plus, I really don't want to be the girl that passes out in the weight room while doing deadlifts...

      I'm not diabetic and so don't have a glucose monitor - are there other ways I could tell? I have cut way down on what my workouts used to be so I don't think it's chronic overtraining. Do you mean overtraining within the workout? Re: breathing - I do hold my breath toward the end of a set sometimes, but I do try to catch myself doing that and try to stay mindful of my breathing.
      My Journal:


      • #4
        Glucose monitors are pretty cheap - I bought one recently for exacty that reason: i wanted to know where blood sugar goes post workout. It is unfortunately not too telling though: when you do say a big lift and your muscle glycogen is lowish then your muscles can really suck a lot of the sugar out of your blood. Before you know it though it is up again - coming either from your liver glycogen stores (if any, but unlikely on 100g of carbs) or from your liver via breakdown of proteins (ie your muscles, unless you have recently eaten).

        I have not yet figured it out for myself how much carbs I need, but I can tell you that for me heavy lifting and low-carbs dont go together. On lifting days I eat potatoes / sweet potatoes / rice (thanks, Kurt Harris) but I have not figured out how much I need at a very minimum. Just keep in mind that an hour of lifting is 300-600cals afaik, so I'd say you'd need at least 50g of carbs for that.