Exercise and BS

For years, when I intensively exercised my BS might go up 20 or 30 points while and right after exercise. After my body cooled down it would return to normal. I always figured exercise was overall a good thing and worth the bump up since the rest of the time I was probably lower than if I didn't exercise.

This week I went from moderate aerobics to pretty intensive circuits. My BS shoots up about 20 points and then stays there. My body will crave carbs but if I eat them it elevates my BS even more. I have given in and eaten a piece of whole wheat toast after a 1 carb breakfast and workout and all it did was shoot me way up and I still felt awful.

I'm beginning to wonder if I need to not do intensive workouts. I have felt so awful this week I decided I wasn't working out this morning since I still have a final this afternoon. I took one on Tuesday and really struggled because I felt so awful. This one is a tough class and decided one day of exercise wasn't worth blowing it.

So will this get better? Why is my BS going up instead of down? Some of my best readings comes after a moderate workout, do I just keep going and hopefully intense will become moderate and I'll go back to seeing the benefits?

For me, the benefits of exercise, which go far beyond just helping to control my BG, far outweight any difficulties I might experience with managing my BG because of exercise. How much and how hard you exercise, however, does have to be taken into consideration when thinking about your BGs, especially if your whole reason for exercising is to help control your BG.

If you you've been low-carb for awhile and are low-carb adapted, that probably explains why you feel like crap after bumping up your carb intake a couple of orders of magnitude with a single piece of toast. If you've never heard of Stephen Phinney, he's a low-carber and researcher who strongly advises against low-carb athletes deviating form their low-carb diet for any amount of time.

I can't explain why, as a low-carber, you crave carbs after an intense work-out. Maybe you still have some a little more adapting to do. Or, as Stephen Phinney also suggests, low-carb athletes really have to pay attention to proper supplementation. That would be my guess. You probably just need to look into what you need to supplement with to support your increased exercise intensity that would get rid of that craving for carbs.

From my understanding, you are looking at glycogen depletion when you are working out. Yes, it is good to low carb, but facts are that while you are doing the intense cardio, you are putting a demand on your body. You have a couple of options -

1) Carb up before your workout. This could be sweet potatoes, oatmeal, whatever. The idea is to avoid the low blood sugar triggering the glyco dump from your liver.
2) Drink something like Gatorade during your workout to keep the blood sugars stable. Again, you want to avoid the dip in blood glucose during the workout.

I know it sounds counter-intuitive to a low carb approach. The thing that LC's forget is that the efficacy in LC is in a sedientary setting. Once you add HIIT to that mix, your body demands energy - and the glucogeonesis is too slow to provide the BG needs during exercise.

Your liver kicks in, and your blood sugar rises. If you have impaired pancreas, your body isn't prepared to deal with it, so your blood sugar stays elevated.

A great book to read is called "The Diabetic Athelete" You can find it on Amazon - http://www.amazon.com/Diabetic-Athlete-Sheri-Colberg/dp/0736032711

There is a lot of great information in there.

She also has another book geared towards T2D - Diabetic Athlete's Handbook - http://www.amazon.com/Diabetic-Athletes-Handbook-Sheri-Colberg/dp/0736074937/ref=pd_sim_b_1

I know that the LC paradigm is all about keeping your BG LOW LOW - but keep in mind, with LC the exercise prescribed with that is almost always resistance exercise, and not high cardio. There's a reason for that.

Here's a good read Jason.


I'm not a low carber either, but there is strong evidence that low-carbing does not hinder exercise if done properly. Evidence also suggests that low-carb may be the peferrable diet for endurance athletes.

I think the limit to low-carbing is at very short and explosive events like short sprints. Now you are talking about fast-twicth muscle fibers that pretty much function exclusively on creatine and glycogen. You are talking about training fast to run fast.

So unless you train like this guy, I think you can do fine on a high activity low carb diet if you pay attention to the supplementation.

I agree. Now, I read the evidence the link you presented, and recognise the doctor. He has limited experience with T1D, but a lot with T2D.

The thing is, when you look at the exercise that he is talking about, it is moderate cardio. (Bike riding, distance running, etc.)

When you are talking about High Impact, it's a whole new level - you are not going at a moderate pace at a max of 75% of your heart rate, you are pushing it higher. LC does not do well in those instances, even for those that are fat adapted. In evolutionary sense, it's logical - you would be doing light to moderate cardio, with explosive resistance, and occasionaly an intense sprint here and there.

With HIIT, it's the equivilent of running a marathon at your fastest speed, or sprinting for a half an hour on end. It's great for conditioning, but depletes your reserves.

I sort of "cheat" and do 20-45 minutes of elliptical after I lift weights. The cardio seems to buzz off. To me, a 20-30 point "bump" isn't that big of a deal and, if my BG ends up high, I just correct it.

I'd add that the other thing that I think is important for endurance on less carbs is the timing of the carbs, not so much eating 500G b/c you are running tomorrow but eating enough, possibly just enough to fuel you, right before you blast off and then maintaining a reasonable load of fuel to keep your BG flat, without blowing up.

So tell me what you do before you run a half marathon. I have mine coming up in a few weeks and am confused about what to eat and if I should eat before. While training I will eat greek yogurt about an hour before my long run and drink my gatorade (sipping) while running. So far this has worked fine without any crashing and burning.

I have toast and eggs before longer runs. I try to eat the meal about two hours before "showtime" so the food will be peaking then, the insulin will be on board but the 2 hour number I'd shoot for would be around 120ish? Then I run and drink Gatorade too. That's worked fine without crashing and burning for me. I usually bring my own Gatorade but all the races I've run have had plenty and it's easier to drink theirs?

Thank you for your advice. I know you have a lot of experience in running long distances. I find the less insulin I take before running the better for me. I am on MDI so I use whole units. Plus the race starts at 6 am so not even sure how much food I can stomach an hour or two before that. In any event I am super excited and can't wait. I am so ready for this!!!!

So let me ask what you eat the day or more specifically the night before a race?

My aim for my longer walks are eating similar food as I eat every day : jogurt , half an apple , steel cut oats ...not always possible when away from home ...but remember to ( and I forgot to check if you are pumping ...apologies )set pump temp basal ( 40 percent ??) . I also use Nuun or GUBREW electrolyte drink tablets ...both brands sugar free .I am not a low carber

PS I am not about to set a world record either, ha, ha

I don't eat anything the night before. I eat a big lunch the day before, my favorite is grilled chicken breasts w/ brown rice w/ veggies and salsa and just eat pretty much as many carbs as I'd eat for lunch+dinner and then take it easy the rest of the day? Mostly to avoid portapotties. Jeff Galloway kind of hints at that in his books and, while he doesn't say "don't eat to avoid the portapotties", he recommends skipping the "pasta feed" and eating very light.

I drink a lot of Propel, no carb drink w/ electrolytes, for the week before the race, adding in a couple of bottles/ day. I realize a lot of the stuff gets washed out but I ran 2x 1/2s in 2 weeks the first time I ran one, did Propel the second one and didn't feel as thirsty. Even if it's psychosomatic, every little bit helps? I usually bring a cookie, I think the Tahoe white chocolate chip/ macadamia ones are good, like 15G of carbs, to munch if my sugar's not quite there before blast off.

I had horrible cramps in the Chicago Marathon last year so maybe I overlooked something but it was hot and I ran faster than I should have, just like the books say "don't run faster than you should!" so we'll see how it goes this year. I trained with a fast group and I'm going to run with a slower group this year I think.

Yeah, absolutely reasonable, which is why I asked Phinney specifically about his research and how differences in exercise intensity might make a difference.

Here is our exchange:


I think there is definitely something to low-carb diets and efficiency of resource use. I don't think it's a case of glycogen pathways becoming more efficient. I think that's a bit too counter-intuitive since less carbohydrate availability should lead to a down-regulation of enzymes in glycolytic pathways.

It is more likely that aerobic pathways are up-regulated with an increased reliance on fats and ketones. I imagine that what Phinney is seeing is an increased aerobic capacity allowing for anything in the aerobic/cardio range to be a lot more efficient. That's a huge range too. Unless you are absolutely at the far end of anaerobic effort, with a muscle compostion somewhere in the 90th percentile of type IIb fast-twitch fibers, I imagine you can modulate even submaximal effort in the aerobic range to include a good HIIT type work-out.

Regardless, I think us high-carbers really do have to give up the idea that low-carbing is only for the sedentary types and that you need even moderate amounts of carbs to maintain a high level of conditioning. At one point, I was a firm believer that it was. I think emerging research is showing us that that is not neccesarily the case.

I am so rigid in what I eat and so low carb that I do think I should up my carbs a few days prior to the race. Do you eat after the race to prevent a crash? I totally get avoiding the portapottie. Do you have any coffee before you race? I think that would be a must to get me revved up.

I don't think that 60 miles in 3 hours is "moderate"!

How many carbs is low carb? Last summer, I had been eating eggs/ ham and was eating a serving of pretzels, like 20G of carb for snacks @ work (I don't "need" snacks however I like snacks!) and my cholesterol had gone up a shade, LDL something like 110 and the doc was like "let's leave it for now but if it goes up more, you should take something" so I replaced the pretzels w/ broccoli & carrots and started putting spinach and broccoli in my eggs instead of ham and cheese. LDL went back down to the 80s and I had a great week of running shortly thereafter, PR 1/2 marathon (1:58, I'd flirted w/ 2 hours but never quite got it...) on Sunday and 20 miles in 3:10 the following Saturday and felt really good during both runs so I've stuck w/ the veggies ever since. I loaded up on carbs before the marathon which didn't go well so I am thinking I'll just stick with my plan next time and not worry about copying the load?

I *always* have coffee. I think I only had 2 cups before the race. Another portapottie idea I did once, come to think of it before the 1:58 1/2, was to have one of those coffee GUs before the race, as my BG was a shade lower than I wanted it to be?

It sounds like my problem is I'm not adapted enough. And perhaps not low carb enough. I eat about 65 grams total per day with about 35 net. For years I ate around 150 then over the last year my readings just got bad. I have no choice but to eat fewer and fewer carbs. Dr. won't put me on anything else. He upped my met to 2000 mg.

Perhaps a little more fat too although I still have 15 lbs or so of extra that I'm carrying around.

Thanks for the article, it was really helpful.

I have no way to correct unfortunately.

I am only on met. It seems to keep me from shooting off into the stratosphere but basically my only choice is to cut carbs. If I eat a well balanced, normal diet which is lower in carbs than the ADA diet but higher than I'm eating I will be well above 200 pp and about 160 fasting even on met. My insurance won't cover an endo and my GP says my A1C is under 7 which makes me wonderful.

I'm beginning to think I need to eat a lot of carbs for the next 2 months and get my A1C as high as I can so that maybe I can get to see an endo and get different drugs. Met has worked great for all these years but I think my body is just reaching another plane of inefficiency.

I also think that the medical community sort of ignores those of us who aren't obese and are T2. I know people who eat junk all day and then get put on insulin. Those of us who try very hard and fail to control by self control get written off since our numbers are reasonable compared to the junk food junkies. I do not consider 200 to be an acceptable number yet it is better than the person who just ate a pizza and ice cream.

You are very sweet (no pun intended) for indulging me in my marathon questions. My version of low carb is about 75 carbs per day. I really don't eat breakfast...just coffee ( I need to bolus one unit for it). For lunch I have nuts and cheese usually so I don't really have to bolus for that unless I'm running higher than I like. my big meal is dinner. I have come to embrace all the great vegetable substitutions like turnips instead of potatoes, cauliflower mash, shiratke noodles and baking with almond and coconut flour. I'm a big veggie snacker too...and nuts. It's a little bit of work but I love what I eat. It's really satisfying and I feel safe since I know what all of it does for my numbers.

I also had higher LDL about a year ago and cut some of the fat out. It brought my numbers within range. I am of the school less is more. I hate to put more into my body in the way of medication than I have to. I think with diabetes you just don't know what is happening if you put too many things into the mix.

I'm thinking I'll do the coffee and yogurt and maybe a slice of my almond bread before the race.

If you don't mind my asking how long have you been diabetic?