I know this is fairly normal, I was just wondering if there was a way I could combat it to allow me to continue doing it without the spikes? I woke up this morning around 10am, walked my dog, went about some chores then around 1pm I did a fasted bodyweight workout, only 20 mins but quite strenuous for a beginner. I’ve not been checking my BG much lately but decided to see what effect the exercise had. 7.7/138! Thats pretty high considering id not eaten anything since last night and my last 10 readings were between 4.7 and 6.4 at various times. Will eating before doing it help stop the spike? It doesnt feel like it’s very healthy to do something that will cause a large spike like that but I enjoy this type of exercise as opposed to just doing boring cardio.
Blood sugar spiked after doing workout
Personally, I don’t worry about it. But you could try eating beforehand, or even eating something like smarties beforehand:
Given that glucose supplies the energy for explosive power, what is the reason for considering this a problem? Are you still very insulin-resistant, so that you are afraid of what your insulin is doing?
Exercise helps promote mitochondrial healing and increases the metabolism, both of which are very good things. I think that any bodily response to exercise is therefore not likely to be a problem.
I agree with this. There’s a reason blood sugar goes up (though I have yet to figure out why; have some theories though).
Why are you trying to stop your body from its natural response to such healthy activity on your part? This is a win-win.
Don’t let lab results referenced to the “normal population” (i.e., including many metabolically ill people) tarnish your interpretation of your body’s generation of its own fuel from body fat stores. This is strong evidence that your body is healing and improving itself.
Onward! 
I have no clue tbh, idk how to tell. I think initially it just freaked me out cus I’ve been trying to keep my BG as stable as possible as I was previously having hypos but Ive not had one now for a few months so when I saw that number fasted I didnt like it. Suppose my concern would be if I exercise then go eat after my numbers could obv jump higher still and then be elevated later into the day. If Im doing that workout 3x a week it could make my average higher. Is the higher spike due to being overweight? Does a metabolically healthy person have the same spike with HIIT training?
If you are not eating carbohydrate, then you will not produce an insulin spike worth worrying about. If you want to put your mind at ease, try getting a continuous glucose monitor, and see what your serum glucose is doing throughout the day. I suspect it will be within a fairly narrow range, even with the rise related to exercise.
The “same spike” is hard to define, since everyone is different - both from each other and day-by-day. But the short answer is: yes. Metabolically healthy people who are into measuring such things do detect a spike in serum glucose from intense exercise when eating with highly restricted carbohydrates.
It’s called gluconeogenesis and it’s the 8th Wonder of the World. Enjoy!
Yup, low carb HIIT exercises increase glucose. Muscles are glucose sinks; they can uptake glucose without insulin being raised. Gluconeogenesis to meet demand of energy required for HIIT, muscles uptake.
My cowardly solution to this was that I measure my blood sugar hours after exercise. The dawn phenomenon causes it to raise when I get up, and when I get back after a run it will usually be up to 120 / 130. I wouldn’t worry about it.
Nothing cowardly about going out for a run and then sticking yourself with a needle. Kudos.
138 after a workout isn’t even remotely high, not sure what your baseline is, but even in the 80’s I’d hardly call up to 138 a spike.
My baseline is around 90/100. Im am going to continue to do my workouts but I will experiment with eating before to see if it has a notable difference. Im enjoying the workouts and theyre obv good for me, I’m aching in places I didnt even know I had muscles 
Same here (slightly higher than pre-keto, but now with minimal swings). Being highly insulin-sensitive, my serum glucose level often meanders upward by 20-25 post HIIT, less so with cardio than strength training, then eventually settles back to roughly 100 or so without eating my first meal.
It’s all gluconeogenesis at work. Makes me proud of my body for taking such good care of itself 