Post exercise BS bounce

Does anyone get this with exercise? With exercise, and supplementing with sugary goodness if your starting to go low, then finish the exercise, but have your bs continue to rise? Im talking small amounts of carbs being ingested too.
An example:
I will eat 1 cup of brown rice with some chicken and vegies for lunch, wait an hour or so and then swim at about 8mmols and rising (no bolus). I swim a mere 1km which takes less than 20 mins (im slow!) and my bsugar comes in at about 3. I have 2 jellybeans and in an hour im at like 7.5mmols. Or similarly, i will have a few glucose tabs, wait a little bit, do some technique drills etc, come out of the pool at be around 3 mmols again (i feel these lows so stop at this point) and NOT treat, but in an hour i bounce back up to 6mmols?
Why the delayed vicious rebound of bs? my 8 units of lantus holds me steady between 4.5-5.5mmols each morning upon waking and gives me good numbers during the day, so im not sure if i should lower the basal just because of some exercise which doesnt take too long. Anyone know why this rebound occurs? I have to treat lows, but im hardly giving much carbs at all because i just bounce right back up. If i finish a session and im 3mmols i dont treat because i always spike back up. Is this a delay from the lunch rice meal?

Maybe both the pre-exercise food and the post-exercise spike are adding together to produce the effect you're observing? I usually test, bolus and then shower to clear out the post-spikes, and then eat something afterwards.

Your body is releasing hormones that cause the rise in BG. You can run a sprint and it will cause a rise in BG. When I was cycling my BG would drop low and I could sprint and this would bring it up to a safe level but there is a point of no return when the body has no more glycogen and or glucose for this type of response. If you swim at a steady pace for a hour I bet your BG will drop and stay low. You should be able to stay in a zone by training with a Heart rate monitor and testing.

You have mentioned this brown rice in several posts, I found that loading carbs a few hours before activity was unreliable it was better for me to load at night and use fast acting carbs to fuel my activity...cycling was kinda steady so after about 30 min I could start introducing carbs at a predetermined rate to maintain BG control during the long ride. I also never had good luck completely skipping a bolus. I worked out my BG issues every winter taking 45 min spinning classes and later wearing a CGM...the classes where brutal but it was a safe place for me to push my limits and more. Keep a log book, track everything including sleep, days off, and what happens when you take a day off. You will probably have better results if you train every day, consistency will probably give better results than trying to add in recovery days.


I get varied reactions to exercise. It can sometimes varying for me doing similar kinds of exercise depending on time of the day.
i.e. If I run 10 km in the morning vs the afternoon I can go low vs high if I apply the same routine.
I don't really have any good advice as its the bit that I struggle with the most but stick at it.

My experience is I can eat roughly 30 carbs with no bolus for every hour of medium intensity exercise. A cup of brown rice is 45g roughly and for me a fairly slow action profile. I would judge a cup of rice as too many carbs for a 20 minute swim, instead I would skip the meal if possible pre-swim and use something with a faster action profile such as a banana or like 15-20g of jelly beans and give that a try.

For me, I notice very different effects depending on the exercise I'm engaged in. Long, slow runs cause me to drop at a moderate pace and a small amount of carbs (20g or less, along with a reduced basal rate) can keep me steady and relatively within range. However, I am more likely to go low the next day but not dramatically so.

Exercise that involves an adrenaline rush of any kind has a completely different effect. I will spike (usually upwards of 250 and even to 300). I rarely give a correction bolus in these situations, because I will come crashing down. What I have found to work is to increase my basal rate by about 30% or so. But I have to be careful because these kinds of high-intensity workouts can lead to some really low BGs the next day. I explained this to an endo once and she acted like I was crazy. Turns out that post-exercise low (a day later) is quite common among T1s.

As for your situation, I agree with AcidRock.

i think you may all be right. Might see if i can swim first, then eat and have a slightly reduced bolus afterwards. Thanks all:)