Afternoon cycling T1D strategy

Saturday morning is my cycling day.

This is the day that I spend hours on the bike, touring multiple cities, sometimes with my favourite cycling friend, but these days, mostly alone.

cycling Katie

I’m a fair weather cyclist – especially when I’m riding solo – and my window for cycling this past Saturday was riddled with monsoons.

I did NOT go for my ride.

My husband did…sort of 😉

He set up the smart trainer in front of the TV and rode Zwift up the Alpe d’Huez for 2.5 hours!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I don’t think I can put enough exclamation points on the screen to emphasize just how ridiculously appalling this is to me.

I mean, seriously, 2.5 hours on the TRAINER, with NO sites or scenery to pass the time – just a video game like setup of mountains and volcanoes and icons of so-called other people cycling the same route, and no one telling you to increase your speed or bare down with grit to get up that mountain – it’s all up to you.

He did have our son next to him for a good part of it cheering him on and telling him when he was going too slow. But still, I’m pretty sure I would have been bored out of my skull to sit there for more than 10 minutes, let alone 2.5 hours – dripping sweat.

But then, Sunday happened.

I was feeling out of sorts about not getting my ride in, so I scheduled myself with a Peloton class later in the afternoon.

Since joining Peloton a few months ago, I’ve accomplished just over 50 rides – all 30-minutes max. But on Sunday, I increased it to 50 minutes.

And I didn’t get bored!

I know, I know, it wasn’t 2.5 hours, but that’s just plain crazy 😉

I have two instructors on Peloton that I really like, who are able to push me out of my comfort zone without annoying me – that’s huge!

Afternoon exercise sessions can be a challenge.

Because I like to eat every 2-3 hours, I need to be mindful of my insulin dosing. If I give myself too much insulin, I’m setting myself up for hypoglycemia, but if I don’t give myself enough, I could be taken out by hyperglycemia.

Oh the joys of being active with T1D, hey – so much to consider, so much to calculate!

I didn’t ride until 4, but had a snack scheduled for 3, which meant if I bolused, that insulin would be peaking right at the start of my session, which is not optimal.

I had a couple options:

Opt not to have a snack at 3, wait until about 3:45 and see what my blood sugars were doing. If they were less than 7.5 mmol/L, have a light carb-only snack – without bolusing – of about 15-25 grams carbohydrates such as 3-4 Swedish Fish, ½ a honey sandwich, an applesauce pouch, etc., etc.

Eat my normal snack at 3 p.m., which contains about 15-20 grams carbohydrates (½ apple) with a small amount of protein (almonds or peanut butter) and reduce my bolus to accommodate for the exercise, as well as a basal reduction.

Eat a small snack at 3 p.m. containing both protein and carbohydrates (~10-15 grams) without bolusing.

I chose option 3.

My blood sugars at 3 p.m. were 5.3 mmol/L. I had 4 Mary’s crackers with 2 pieces of cheese.

One hour later, my BG was 7.2 mmol/L.

I reduced my basal by 50%.

Half way through the session, my BG was 7.1, and at completion it was 6.7 mmol/L with an angled arrow up.

Because I didn’t have a bolus for my snack earlier, and because I implemented a basal reduction, I was now at risk for a spike due to low levels of insulin in my system. To battle that, I increased my basal by 50% for an hour post exercise, and gave myself a correction dose in the amount I would have taken for my earlier snack.

You all, this trial and error effort was killer!

I did NOT have post exercise highs!


😀 😀 😀

I did, however, wake up with low blood sugars in the morning. They were fine when I checked them at 3 a.m. (5.0 mmol/L), but by the time I woke at 6:30, they had bottomed out to 2.4 mmol/L, and it looks like the drop had started at around 4 a.m.


That, my friends, is an area for further strategy adjustments!


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