BG at start of exercise

Several times I’ve seen recommendations to get your BG up before exercising (lets say running for an hour just for example). I hate this idea due to damage from the high BG, but also due to some personal outcomes - at 140 mg/dl I get ravenous, at ~155 I get nauseous, at >200 I get muscle cramps. At BG >150, if I run for 3 miles I guarantee you I won’t be able to sleep due to incredible muscle cramps (calves mostly). I can still run at 70, and don’t start feeling week until below that.
Don’t others get similar problems with being so high? What about recovery? I think I feel better the next day if I don’t ever get that high - but that’s just something I think, I don’t know it.
Comments? How do you feel about the benefits of exercise vs the negatives of letting your BG get that high?

i never jack up my blood sugars on purpose, i think these recommendations are so that the medical profession can be on the safe side…i usually start out at whatever my sugar leve is at the time…if it is perfect 100…then i will go run and carry sugar with me…from, and from wearing a cgm…i see that i will need sugar at the rate of 1.4g of carbs per minute…except for the first 25 minutes of running because the sugar is coming from my stored glycagon…right at the 20 minute mark i will eat some sugar and then just keep eating to how much longer i will be running…now that i am on the pump, i might decrease my pump during the run, to help offset the lows i will have later on from the 90minutes of running…no need to raise your sugar to 250 before you go running…yes it might come down but this could take 90 minutes

My best operating is around 120-130…that’s where I feel the best (have the most power on the bike or while running). I know that sometimes when I’m over 200 I notice a loss of power, and again when I’m low (trying to cycle at less than 70, I just have this huge wall of fatigue that hits me). I’ve tried training/racing below that, and I can do it, but it’s a slippery slope for me as suddenly I’m 70 and trying to eat everything I can get my hands on to keep from crashing for the last few miles of the ride or run.

In your example you say that at >150 you run 3 miles and will have muscle cramps. Are you running this as a tempo run (HR below lactate threshold?) or are you going full-out sprint? I only ask b/c lactic acid would rush into the muscles and could definitely causing cramping if you’re pushing yourself more than your body wants to go…but if you’re just training or going for a casual run (a run where you can continue a conversation should be well below LT), the risk of cramping should be minimal, or at least greatly decreased (assuming you’re not sweating out every bit of electrolytes and causing an imbalance at the cellular level).

Regardless, I would agree that I feel better when my numbers are more in control at the end of a long ride or run than if they are out of whack…I’m also able to control post-activity BG levels if I end w/ a BG in target range as opposed to fighting a high.

I used to elevate my blood sugar before I went surfing because I didn’t bring anything in the water with me, and was scared of a low far from shore. But I am working on ways around that (have something I’ll post about once it’s tested). For a trip to the gym though, I never elevate. I usually start around 90, and if I see a downward trend then I’ll have a glucose tablet at 75ish. Generally though, if I’ve had enough protein within a couple hours of working out, my sugar may rise to 100-110, but it rarely falls. The only time I had trouble with lows due to exercise was when I had too much insulin on board, either due to faulty basal rates (I’m now at less than half what I started on) or because I was eating a lot of carbs (I now stick to under 15 per meal, tops). With proper basal and food in my system, I don’t have any desire to elevate, for the reasons you mention. (I tend to do about 30 minutes of cardio at 80-90% max heart rate, followed by 30 minutes of weights fyi. i am by no means an endurance athletes)

Calf cramps are a problem for me and have been for years. Calcium (+Magnesium) helps. But, lately that doesn’t cure it any more. Keeping BGs as low as possible, plus extra calcium + exercise is the best I can do. I’m thinking of adding some sports drink to the mix to increase my salt intake - thinking Accelerade (were you the one that posted about that?). I jog 5+ days/wk, generally ~3 miles or 45 minutes (slowly) and weight lift about 45 min/5 days/wk. I do yoga on “off” days, because I just can’t sit still.
I’m a compulsive casual exerciser - a 30 year T1 who has always been large (my dad’s family are all diabetic, my mom’s family is all obese, I got both). So, I’m not a true athlete, I’m an athlete wanna be.
I only get cramps when exercising if my BG is high, or sometimes ~50 miles into a long bike ride. I get the cramps mostly in the middle of the night.

I’m glad to see these answers, as the suggestion to start with high BG really is rampant in this group. I thought I was nuts and/or unsafe.

The cramping thing is interesting. Sorry to hear you’ve got to hassle w/ them! Nobody likes that…

I’ve used accelerade before. It’s got a 4:1 carb/protein ratio, and their flavors are pretty good (don’t let it get hot for several hours on the bike…it gets a little ‘tangy’ :-/
You might also look at Nuun or Heed for adding to water–it has electrolyte replacement stuff in it. I think camelbak might make something like that too, but I haven’t ever used it.
You could also try (on long rides/runs) some sort of salt replenishment pills: S! Caps and Endurolytes are two that come to mind that I’ve used w/ some pretty good success…there are others though.
It sounds like you’ve got it dialed in pretty well w/ the amount of activity and w/ your glucose needs–that’s great!

I never try to get my sugar up before a ride. But if I am a 70 I will eat raisins because below that I will bonk. 120 to 130 is best.
I am on the pump so anything above a 200 I will give some insulin about half what I would normal give.
I have found that if I get low on a ride say 50 I can compensate with raisins and be ok but about 30 mins later I will cramp.
I cramp easy so I take Endurolytes from Hammer they don’t have any carbs.

I’m envious of all you guys that can workout starting at 90 or 100. I seem to be so sensitive to exercise and insulin. I spent years bonking at the gym because I had too much basal going on, or active insulin from a recent meal.

These days I turn my pump down to 40% of my usual basal while I workout and I can usually avoid eating any sugar and/or adding more insulin during my workout. I stay pretty steady. If I’ve had a meal within the prior 3 hours of going to the gym, I have to turn my basal down even more. If I am high going into it, then I ride the bike at the gym for ten minutes or so with full insulin (maybe 1/2 a unit) to bring my sugar down for the rest of my workout. Sometimes I can drop 100 points in 10 minutes of the bike at only a moderate intensity.

I don’t like the idea of starting high just to avoid lows either. It seems counter productive to workout to improve health but run your sugars high at the same time. A balance suits me best, and I continue to work on finding the right mix. Though I’m still not totally satisfied with my plan.


I try to be at a fairly normal bs when I start exercising and I rarely have lows if I’m doing an exercise that’s normal for me. However, if I try something new, I inevitably have lows during and after exercise, but once I’ve done that new exercise a few times, my body gets used to it and I don’t get low.

As for the cramping - I’m the same with the calcium and magnesium. I take that before bed and if I forget I get horrible calf cramps.

I was thinking the same thing! I am envious, too, about those starting numbers. I am guilty of letting myself creep up before I ride, and was also concerned about the longer term implications of that. But like you, I am super sensitive to exercise- I have fallen from 200+ to right around 90 in a half hour. It really depends on the length and intensity of the ride. I am not on the pump, yet, and would LOVE a CGM to tell me where I am trending. I think this is what makes me really cautious- I cannot reduce my basal rates because I take Lantus at night. Once you take it, you gotta live with it. Does anyone have any advice for that? I am training for the Tour de Cure (I was just diagnosed T1 in January and getting back on the bike and training has been a god send :slight_smile: The lowest I have been was 50 about mid-ride, and that felt like I was riding through tar. I have found that I need to start out around 200, and then still eat every 30 mins to keep myself from going hypo. Does anyone have any other suggestions?

I have seen recent posts about this and have wanted to comment, because I do NOT agree that you should shoot to be 200-ish before exercising. You should not have to do this especially if you are on the pump. It’s all about Insulin on Board. There is no reason you should’nt be able to go out for a run with a BG of 100.

Before a morning run, I will lower my basal by about 50% 2 hours before the run and will eat 15-20 carbs 5-10 minutes before starting. These 2 things are the key.

I don’t have too much of a problem running when I am high, but I feel so much better when my BG is in a good range.

Thanks for starting this topic. It was much needed.

When I start exercising for longer than an hour I always have some sort of fuel with me BS 120 to 130 hopefully. Hammer gel, Carb boom or a mix in a water bottle. I like the ones that just have Maltodextrin in them the ones with rice syrup send me up to fast. I start to eat some within 15 min of exercise, since it is a longer chain sugar it takes a little while to get in my system. Then I eat some every 15 to 30 min during exercise. I test during exercise my CGM cannot keep up with how fast my sugar can change by the time it sends an alarm I have already compensated for the high or low it is a nice back up and the trends are great. If I get low I will eat raisins, they raise my BS fast and do not upset my stomach. I do go up after I stop so I test and give a bolus when I am done. I take lanuts too at night and time it so it peaks when my morning highs start. I use a pump for blousing and find I need a little extra insulin during exercise 0.15 and can compensate for highs on my rides easier that giving a shot on the bike. My endo does not approve of pump and lantus at the same time he says one or the other but what does he know “ha ha”.

Look at ‘Energy Drinks’ in the group Cycling Diabetics
Good Luck

My endo actually recommends specifically using a Lantus/pump combo (sometimes using Lantus as the full basal, sometimes as a split I believe) for people who are especially active, so you’re definitely not alone. I’m not a pumper, but I think if I were I would continue to use Lantus.

Wow Thats good to know.
Thought i was out on my own.

Do you split your Lantus? (And I am glad Kent brought up the peak- I know its not supposed to have one, but I feel it does for me) Almost every night I go low around 3-4 am- and it seems to happen even if I do snack before bed. I have gradually reduced the units I take, but I still seem to bottom out then. And the smaller amount seems okay for the daytime- I usually don’t run high- I wonder if the amount that I have been riding (from no activity when I was really sick at diagnosis to everyday long distances) has increased my insulin sensitivity? Is that possible? I just bought Sherri Colbergs book and am trying to memorize it now :slight_smile: My first appointment with the Endo is next week.

I am going to try those… Its funny that this discussion was started today. The same thing happened on my ride this morning. Although I tried to start lower than I usually do (I was at 184, and only had Lantus on board) Again, within 30 mins I was 54. Which totally sucked as I sat on the side of the road, sweating and shaking and sucking on candy :slight_smile: This may be a really stupid question, but when you start at 120, the carbs you consume from the beginning- they are to replace what you are burning through, right? I think maybe I should rethink my process and work on maintaining a good BG rather than work on lowering it (as I do now) I am just scaredy-cat :slight_smile: because I am still really new to T1 and fear something happening while I am alone on the road in the desert :slight_smile:

I would eat some sort of gu (maltodextrin mix ) right at the start of your ride and continue taking some in the first 10 min allso i eat penutbutter (fat protein) before morning rides so that keeps my BS up longer.
I find that within about an hour my sugar stabilizes as long as i keep the same fuel going in.
You should ride with a group and make sure some one knows your a T1.
Do you wear an ID thats important. Take small steps just ride for an hour and fix your low at start then go for 2 and fix any problems and so on. I give my Lantus late about 9:30pm but i get morning highs so the peak takes care of that, sometimes. On a 50 mile ride i will use about 70 carbs during the ride.
Exercise defintly helps insulin sensitivity. Yes the carbs you consume replace what you are burning through.
Just sugestions
you can figure it out lots of us have!
See ya on the streets

I joined so i could…vent about my situation, or get kicked in the ■■■ maybe.

It’s terrible, i read you guys and i feel like crying cause,…my fear of the low ( cause i had so many…) changed me into another person.
I used to walk but just a 15 mins walk would get me under 60 in less than 10 mins. Sometimes, just showering…give me a low. It seems that any physical effort i put trough , takes allllll my carbs away in a blink of an eye. So…at the end, i simply quit trying.
I was invited for a walk in a birding parc that i love this week…and i was so scared, i wanted to go but the fear took over me.

The result of these fears: i gained 45 pounds in less than 6 months.
I was on insulin and became very sick, then metformin , i am intolerant. I was on januvia, i was intolerant as well, and now i am waiting to see my endo this week. He seems to wanna give up on me.
I’m so tired of this…i wanna be like you, go fearless, and MOVE that body of mine without fainting.

What can i do…?

WOW I always thought type 2’s had it a little easier than type 1’s.
Getting to where I am today has been a long road. 37 years with T1, countless Ambulance rides to the hospital, A1cs well above normal, testing urine instead of blood. More than 7 different insulin’s and 15 different regimens. It is not easy! In the beginning it can seem daunting but it can be done.
Hang in their Good luck!!