Daisy Mae's swimming BG thread

@Eric , i am trying to figure out where i fit in in the scheme of things regarding high/low BGs before, during and after exercise. as a swimmer, i must detach from my pump before i swim. so, i dont have the luxury of setting a temp basal rate. i swim w/out IOB at all. just a pre-swim Ucan bar 1 1/2 hour before i jump into the pool.

Ii do this for 2 reasons: 1) b/c my BGs go low from the exercise, and 2) b/c my body needs the fuel. now, even that i go from about 200BG before i swim down to about 60BG post swim, i need to hook back up to my pump and give myself a bolus to prevent a spike post exercise. i dont know how high to rate my workout on a scale of 1-10, but i am by no means killing myself swimming my laps. i swim moderately, but am not exhausted afterwards, just high from endorphin rush. muscles are tight and strong (i am very lean) but not hurting from lactic acid build-up. before i connected with you, i posted a question about why my BGs would shoot up (sometimes to 300s) post swim. you suggested that i give myself a bolus when i get out of the pool even when i am low. i have followed your advice, and i have never spiked once since then.

So, heres the deal: i go low from my swim, but i still need to give myself insulin afterwards. whats up with this? why does this happen? just very curious and figured you were the go-to-guy :wink:


Hi DM,
Glad you could join us here!

Let’s start with a few basic thoughts, just to make sure we are on the same page about some things!

  1. You know there are a lot of ways to raise your BG - hormones in the form of stress, being sick, or exercise. Your BG can rise from your liver releasing glycogen just from getting out of bed in the morning. And of course, delicious food can raise your BG.

But…there is only one way to drop your BG. The big drops you are talking about, 100 or more points, there is only one thing that does that - insulin. Nothing else. Exercise does not do that. Exercise can only amplify insulin. So can higher temperatures or different infusion sites. However nothing but insulin is dropping you that much. That is the first important concept to grasp. It is not your swimming that is dropping you, it is your insulin. The swimming is only amplifying it.

  1. I personally would not want to start at 200 and drop to 60. I’d rather start lower and not drop that much. The way I do that is with less insulin.

  2. This isn’t a quick fix. It takes time to get these things figured out. But let’s plan on being diabetics for a few more months. We have time to work through this. It takes patience.

  3. You may lose a few swimming sessions to bad BG until this gets figured out. Every bad session teaches something, so it is not a waste. But just accept that sometimes you lose a few before it gets better. So be willing to lose a few swimming sessions to bad BG for a while until the numbers start to come together.


@Eric, in @daisymae’s case:

  • What do you think is actually causing her to go high after her swim?

  • what would you aim for, in terms of where to start and where to end? And how would you get about to doing it? I am curious about how you think through that.

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It depends on how hard she is working, at what level of intensity she is working. If her heart rate is close to lactate level, it is a rise from stress hormones. If her heart rate is in the aerobic zone the whole time, the rise is from being disconnected from her pump, and possibly the carbs coming in after the swim, because the swimming will delay the glucose uptake. So I need to get some information from her.

It depends on the things I mentioned above. The starting point depends on the intensity level of the workout, the length of the workout, and how much control you have over basal adjustments and access to sugar while working out.

The best thing to do is get good at starting and finishing at a good BG. Then you start trying to fix what happens after the workout.

The big drop is too much insulin. That much is clear. That would be the first thing I would look at if I was in that situation.


Hey @daisymae !!!

Great to see you here.


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i just need to clarify that i am not “in training” and i dont exercise with the intensity as you guys do. even though i swim for over 1 hour, i swim at a moderate pace. a comfortable pace. i can push myself during some swims, but not with all swims. so i really doubt that i need as much pre swim and post swim as you guys are describing. i just happened to notice the 2 things that you explored: )1 that i go low during exercise, going from a pre of about 200 BG down to about 60 BG when i finish. then, after that, my bgs will rise quickly after my swim unless i give myself a bolus of about .8 units. (a little less if i am not on the low side: .5 units if less than 60. then i detach from my pump again, and shower and go into the sauna.by the time i re-attach to my pump, it has been about 2 hours off of it. so, the only IOB has been my pre swim basal rate at 100%.

also, i am not in the least bit hungry for at least 1 1/2 to 2 hours post swim. i do like the low-fat milk idea, which i would have to bolus for, for the protein and the hydration (i do drink a lot of water pre and post swim, though) i prefer Fage 2% plain yogurt for protein, but i do not ever respond the same way to its carbs, so it becomes a bit too tricky to rely upon it for my workout.

what do you suggest for someone like myself who does not work with your intensity considering all the info i am trying to describe to all you guys? i want to make the most out of my swim as possible. i know that the rest/recovery periods make an enormous difference, but there must be other things that i can do for myself.
all help and suggestions appreciated :slight_smile:

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@daisymae, I am curious, have you considered lowering your basal for a couple of hours before hitting the pool? I, personally, would be a bit nervous about both being as high as 200 before starting, and ending at 60 (on the low side).

Of course, if you did that, you’d likely need to bolus more when you get out of the pool

From what @Eric says and your explanation, this appears to me to be due to

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the thing is that i burn that high BG off while i am swimming. if i go into the pool closer to my regular target zone, i will crash in the pool. also, when i am done swimming,i go high within the first hour, so i am still working off the basal insulin from before i detached from my pump. i hope i am making sense. also, as i mentioned earlier, i do NOT go into the pool with IOB from any past boluses.

Hi DM.
We don’t need to worry about intensity or anything like that if it is just an easy moderate or comfortable pace.

Let’s start with the drop you are having.

It’s what I said in my first reply in this post. It’s too much insulin during the swim. That is what is causing the big drop.

We can fix that if you want. That would be a good thing to start with.

eric, thx for your response. how can i fix this drop? my guess is to do a 2 hour pre-exercise lowered temp basal rate. is that where you are going with this? so, basically, four hours before my swim, i would lower my basal to about 90 or 80% ??? still, i need to account for hte 2 hours that i am detached from my pump. please teach me. i am eager to learn.

4 hours might be extreme. You don’t need to go from having no basal adjustment to a huge number like that. Maybe we can look for a middle ground.

You said you have no IOB before a swim, right? Are you sure of that? You swim long enough after a meal, so there is no IOB?

Can we go through some specific numbers? Can you share basal settings for your day? And the time you go swimming?

If you don’t want to make it public, you can PM me.

hi eric, thx for your message. just got back from a 2hr swim. phew. major endorphin rush :wink:

my current basal rates are:
12am .625
6am .675
8am .65
10am .625
1pm .575
7pm .625

i swim at 2pm ish 5 days a week (M-F ) what i have been doing is this: w/out any active IOB, my BGs are around 100 at 12noon. i eat 1 UCAN protein bar w/out giving myself any insulin. i wait 1 1/2 hours, and let my BGs climb. once i get to around 200 BG, i leave for the pool; it is a 15 min very brisk walk. i test again and then detach from my pump. after 1 hour, i get out of the pool and test. if my BGs are above 100, i get back into the pool for another 15 min. then i get out and test again depending on what my BGs were. if i am 100 or below, i get out of the pool and discontinue my swim. when i get back to the locker room, i hook up to my pump, give myself a manual bolus (depending on 2 things: one being how high or low my BGs are at the time, and 2, how long i have been off of my pump…b/c this will guide me to knowing what basal insulin i have missed for the duration of my detachment)

i detach again, and take a shower and then go into the sauna for 10 minutes. then when i am getting dressed i re-hook, and then i will generally wait 1 -2 hours before bolusing for any meal (as i have said before, i never have any appitite after a workout. i know i should probably try and get some food in, but i just have no interest. maybe i should reach for the milk and bolus for that???)

also, i just need to mention this, even with having given myself a bolus at the gym, my BGs will still climb for about and hour or 2 after i get back home…so i wait before bolusing for a meal, b/c i want my bolus to reflect an accurate BG so i know how much insulin i will be getting to meet my needs for my meal more accurately.

i hope this answers your questions and that some of this makes any sense to you at all. i really want to have a better system; i just dont know how to get there. i have read all of PONDER’s books, etc. gone on line to read about BGs and exercise; talked with my endo and my D nutritionist…every suggestion i get tells me that this is the way i should be managing things. it just seems kooky to me and i wonder how it will reflect my A1c levels, as i have to constantly get my BGs high before they go low. my last 2 A1cs were 5.8% and 6.2% (pretty tight). my endo would like me to be closer to 7%, but what the f–k; i think i have been doing a decent job of things. i just want to improve.

look fwd to hearing back from you,
Daisy Mae


PS: i was curious about what you mentioned about where you insert your pump (or manually inject) on your body and how that relates to your insulin absorbtion. as i am very lean/athletic, and i use the smallest (child-sized) canula that Medtronioc makes. i use my abdomen and the sides of my belly to insert. as i swim, i am using all of my muscle groups, so i have no idea how efficiently i am receiving my insulin. i have relatively no scar tissue despite the length that i have been D, and i rotate every other day. just wondering your take on this.

Happy to see you here Daisy Mae! Interesting subject to.

Hi Daisy Mae,
I appreciate the info about the basal amounts. I was in a rush when I wrote that message, and didn’t do a very complete job. So I have the basal rates now. Thanks.

The useful thing to know is how those compared to your normal mealtime bolus amounts. Can you tell me your IC ratio, and your normal carb intake for a day?

From what you wrote, your basal total is about 14.85 units. And you say that you do not have any IOB for your swim. If you go swimming around 2pm, when was the last time you ate a meal, not counting the UCAN bar?

A little bit of this makes no sense…

How long have you been seeing this endo? Do you like this endo? Would you be open to seeing a different endo?

With your insurance, if you were to find a different endo in your area and go for a visit and just talk to them to see if they were a good fit, would that be covered for a reasonable co-pay?

Before you transfer any records or do anything permanent, would that be a something you could do for a reasonable amount of money?

I can’t imagine leaving an endo with a 6.2%, and them telling you you should be closer to 7.0%. I am just having a hard time with that.

Do you have frequent lows where you need help? How often do you have lows where you can’t get sugar by yourself and someone needs to take care of you? In a normal month, how many times do you need help with a low?

i do have lows, but i have never needed assistance for making a correction. i live with my husband of 25 years and he is always on board with me, but i am always able to get my own juice if i need it.

i have been with my endo for almost 30 years. he is a T1 D also, and i trust him completely. he also has a D ed and nutritionist who works with him, so i enjoy that availability. my endo would prefer that my BGs are around 130ish as opposed to 100. he fears my lows. i understand that, but i am rarely bothered by dangerous lows (in the 30s) i just tested a few minutes ago, b/c i felt a bit wobbly, but my BG was 57 and i took 2 G Tabs and a small piece of chocolate. now i feel 100%. i believe that this was do to a little insulin stacking b/c i ate earlier and then did a dual bolus for my dinner shortly afterwards.

as far as when the last time i ate with a bolus before my swim, i eat breakfast at 7am, then i wait till 12noon to eat a Ucan Protein bar (w/out any bolus) so i am running solely on basal and the carbs from the Ucan. when i hit the pool, i am detached from my pump, so i have no additional IOB, just the previous basal which amounts to about 1.5 units.

my I:C is 1:10 for most of the day, but varies slightly from here to there. i eat very little carbs throughout the day, at least IMHO. on a typical day, my total insulin intake is about 20 units, sometimes a little less, sometimes a little more. i eat mostly lean meats and fish, veggies, and nuts and eggs. since i have been working out, i have been increasing my carbs, but not unrealistically so.

i hope this info helps clarify things and that you can make some sense of it. thx eric.

I am glad you are comfortable with your endo and like him. That’s good. But the 5.8 and 6.2 A1C’s are great. Do not be disheartened by him saying they should be higher. If you are not having problems with lows, then those numbers are tremendous.

Just want to make sure, when you say your total intake is 20 units in a day, is that bolus AND basal? Combined together, basal and bolus total is 20 units in a day?

yes, 20 units a day is for total basal and bolus combined.

sometimes my totals are higher, but NEVER higher than 30 combined.

From the numbers you posted, your total basal in a day is 14.85 units, which means you are at almost 75% basal.

You have too much basal going on. It varies for everyone of course. But for someone exercising 5 days a week, for an hour each time, that number is just too much.

As you stated, you are not bolusing for 7 hours before your swim. Your 100+ point plummets are a result of having too much basal when you are swimming. There is no question about that.

As a starting point, you want to make only one change at a time, so you can see the result. (If you change 2 things, you don’t know which affected it.)

So I would have 1 suggestion to start with. Do everything the exact same, except 2 hours before you go for your swim, turn your basal off. See what happens. How far do you drop when you do that? I guarantee it won’t be as much as you did before.

BTW, make sure your fingers are completely dry when you do your BG checks when swimming. Use a towel first, and then a dry Kleenex which will dry your fingers even better. Wet fingers will give you a false low!

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