Late-Night Exercise and Blood Sugar: What Your Evening Workout Does to Your T1D Overnight
Your Tuesday 8pm HIIT class has opinions about your 3am blood sugar. The data is pretty clear on this. Neil is giving you fair warning before the episode starts. This episode covers the timing of exercise and its downstream effects on both...
The episode, word for word
I want to be completely transparent about what this episode is and is not.
It is NOT me telling you to take a lavender bath and read a physical book by candlelight and journal your intentions while your essential oil diffuser gently aerates the room.
It is also NOT me telling you that "sleep hygiene", which, nobody calls it that, nobody has ever called it that in a natural conversation, it sounds like you're brushing your sleep's teeth, is something you need to add as a twelve-step protocol to your already complicated evening.
What this IS: a conversation about one thing. Just one.
My name is Neil Greathouse, and this is Your Best T1D Year.
All right. Pre-sleep routine. And before I get into it, I want to make something clear.
You've been managing T1D for however long you've been managing T1D. You already have a pre-sleep routine. It involves checking a blood sugar or a CGM. Maybe setting an alarm. Maybe running through the mental math on active insulin. Maybe making sure the glucose tabs are where you can reach them at 3am without turning on a light. You've been doing this for years, probably without ever calling it a routine.
The point of today is not to build something new from scratch. It's to extend something you already do by about thirty minutes, in a direction that's going to help your sleep.
OK. Here's what I want to say about routines in general, because I think there's a trap that T1D brains fall into.
We are very good at complicated systems. We have been building complicated systems for our disease since we were diagnosed. We know how to optimize. We know how to track, adjust, analyze, correct. And when we hear "build a routine," our brain says: excellent, a system, I'll put together a comprehensive fourteen-point protocol and start on it Monday.
And then on Wednesday, the fourteen-point protocol is gone because life happened and you missed one thing and then the whole thing felt broken so you dropped it.
This is not a fourteen-point protocol. This is one thing. And then, if one thing works, another thing. The research on habit formation is pretty clear: a single anchor behavior is dramatically more likely to become permanent than a multi-step protocol. One thing, repeated consistently, becomes automatic. Then you add the next thing.
So. What's the one thing?
Honestly, it depends on what's most true for you right now. But here are three candidates, in no particular order.
One: the blood sugar check thirty minutes before bed that we talked about two weeks ago. If you haven't tried that consistently yet, that's your one thing.
Two: screens down sixty minutes before sleep. Not in a room across the house. Just face down, out of your hands. The blue light conversation we had, this is the behavioral version of that.
Three: consistent bedtime, within a one-hour window, three nights this week. Not all seven. Three.
Pick the one that feels most manageable. Not the one that feels like it would make the most difference. The one that feels like you can actually do it tomorrow and the day after.
One thing. Not because I think you can only handle one thing. Because one thing is how habits actually start. Seven things is how you feel overwhelmed on Thursday and drop all seven and feel bad about it, which raises your cortisol, which affects your blood sugar, which disrupts your sleep. I've watched this happen. I've done this exact thing. To myself. Multiple times.
One thing.
Pick one of the three pre-sleep behaviors from today. Write it down. Commit to it for five nights.
Not because five is a magic number. Because five is enough nights to know if it's making any difference.
You've been managing T1D for a long time. You've built more systems, adjusted more variables, and made more decisions about your body than most people make in their lifetime. You are genuinely good at this.
One pre-sleep decision is not a lot to ask of someone with your track record.
You're not doing a bad job. You're doing a difficult job. And you keep adding to the toolkit. I'm proud of you.
Type 1 diabetes is relentless, but managing it doesn't have to be. New episodes every Monday, Wednesday, and Friday. You're not doing a bad job, you're doing a difficult job. Nobody remembers easy.
This is the script as read on the mic, lightly tidied for reading. Education, not medical advice. Talk to your care team before you change anything about your insulin.