Type 1 Swimming bloods

The effect exercise has on our BG is a complex.
It depends on many things such as the type of exercise, how strenuous it is, how fit you are at that exercise, how long you do it for, whether you have any insulin on board, ...

For example (sorry about the "me me me - ness")
- walking has no affect for me. I can walk 10 miles and my BG stays pretty stable.
- running for 30 minutes and my BG would plummet if I didn't lower my insulin
- climbing for and hour and my BG would rocket if I didn't increase my insulin

As your Levemir is a long acting insulin which lasts about 24 hours, it will have little affect during your swim.
Increasing your humalog (your fast acting insulin) is going to have the affect you need but I understand your reluctance to do so.

For me, climbing is equivalent to your swimming.
I am now on a pump so I can increase my basal. But in my pre-pump days, I would give myself a boost of Novorapid before I started scaling the walls. I would take enough to target a BG of 3.0 if I wasn't climbing (my usual target is 5.0).

Edited to add: don't forget to test more than usual for the next 24 hours after swimming. The extra BG may have come from your liver which leaves less reserves for the rest of the day and may result in a later hypo.

Hi @chris001962 ,

Welcome to the forum..!

Though stress can cause liver dump of glycogen into the blood stream..
So can excersise?
That extra burst in activity kind of mimicks the "fight or flight" associated with the whole stress thing as the body requires the fuel to do something about it? Wrongly this can cause an annoying post excersise spike.

What did you test at, prior to the swim..?

Going to tag in guys like @therower @catapillar @Type1Bri (sporting peeps!)

Hi @chris001962 I swim most mornings, before breakfast.

Trial, error and a good deal of frustration while on MDI, then on a pump, experimenting with every combination of porridge/insulin/no breakfast/no insulin/post-swim no-food bolus/increased temp basal rate on my pump after swimming have led me to what I do now:

Get up, test, have half a unit of insulin (if BG is 5-6).
Disconnect pump, wrestle self into swimming costume and clothes, drive to pool (6 mins).
Swim 20 lengths.
Steam room, shower, reconnect pump, test.
Take my breakfast insulin, remembering to delete from the equation the insulin I took before I left the house.
Grab free coffee from machine at gym (optional). I save it for elevenses!
Drive home, cook and eat 2 boiled eggs.

If I swim with no insulin on board I will be in the teens pretty quickly.
If I don't have insulin straight after my swim I will spike before breakfast.

It's taken many many months of trial and error to find what works for me. I used to raise my basal rate to 130-150% for a couple of hours after my swim, but these days I just have my breakfast insulin straight after my swim and keep my basal the same, and that keeps me steady all morning.

But without taking insulin before my swim my sugars just climb.

Hi @chris001962. Well I think you've had some great advice already. @helensaramay rightly points out how different exercise affects sugar levels. @Snapsy points out the need to try, adapt and modify things to suit you.
On a personal level, if I know I'm going to do exercise that will cause my sugars to spike ( intense weight training ) I will bolus a small amount of insulin to try and marry up with when my liver dump/ adrenaline kicks in. It needs a lot of confidence and practice to get it right. I wouldn't like to tell you how I work out my insulin regime regarding training because we are all different and what works for me could ultimately be problematic for you.
As already stated you need to use trial and error with insulin ( amounts and timing ) and maybe carbs before or after training.
Another option would be to adjust how you swim. Try doing 3x 10 minutes, have a rest in between each set. You could also try short bursts of high intensity swimming, do x amount of lengths hard and fast for a short period of time.
Unfortunately I swim like a brick in a lead life jacket, so can't really offer any specific swimming advice.
Hope you find a solution.
I'm quite happy to have a spike after training as I know it'll only be short lived and the benefit of training far out weighs the temporary spike.

therower said:

I swim like a brick in a lead life jacket

Click to expand...

I LOVE this! Now Snapsy 'swims' but can't actually do any recognisable strokes (despite having the GDP of a small nation having been spent on swimming lessons as a nipper) - I do a deep doggy paddle (and get openly laughed at but don't care!). Might I use your lovely turn of phrase myself, @therower ?

Top banana, by the way!

Hey @Snapsy . Of course you can.