Exercise and temp basals

Hi everyone! I’ve really appreciated all your advice over the past few months. I’m currently on a journey to better health and as a result I’m losing weight and am down over 20 pounds. As we all know losing weight with type 1 is complicated because of how much you need to adjust your insulin. I’m finally at the point where my basal is steady and not causing lows so I’m adding back in activity. I’m curious what temp basals work for you all. I went for a normal paced walk a bit brisk here and there(really only for 1 hill). I started with a temp basal of 15% less a half hour before. Blood sugar was good before I left at 100 but I still took in about 8 grams of carbs. I went for a half hour walk and decreased my basal from 15% to 25% while I was actually walking. I still managed to go low after a half hour which surprised me because my pace was by no means strenuous and I had a small snack. I went up fairly quickly after so I don’t think my temp basal is too far off. Really I’m just curious what people do for activity. For hard activity I used to do 40% but for walks I used to do 10% and I was fine. Any suggestions help but I know it will ultimately be trial and error on my end.

You can ask your endo, and of course please do, but I’m afraid trial and error is all there is, really. You know from personal experience that a small decrease used to be enough for you, but now it’s not. And other people have experienced everything from actually needing more insulin when they exercise to some folks needing zero basal and extra carbs and still going low.

FWIW, when we asked our endo the same question, she suggested we start by reducing basal maybe 10-15%, but emphasized that really it was just going to be a matter of trying something and seeing how it went. And you’ve already done that, so try reducing it a little more next time. (Super-helpful, right? Sorry! :nerd_face:)

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Your advice is spot on! I figured I’d get trial and error but every now and then someone says something and I think to myself why didn’t I think of that? Trial and error is really a diabetics best bet like 80% of the time.

adding to @srozelle, basal reduction isn’t the only variable… so with zero IOB (insulin on board) walking, 10-25% (of my normal rate) mountain biking 80% to 100%. If you’ve taken ANY insulin above basal… a correction or a meal bolus for example, the next 4 hours means you have IOB and if I have even a unit on board I’ll use 100% (suspend or zero temp basal) and I’ll still need carbs. now that’s me. this is not too hard to do you just watch your CGM or test more and add carbs as necessary.

a thought. the reduction of 15% to 25% while walking didn’t do anything… because it takes about 45 minutes before a change in basal makes a difference. so you were really testing at 15% reduction the whole time. so make a reduction, be aware of IOB, and maybe at 45 minutes before… try that 25%. if it’s too much correct, too little you add carbs. truly trial and error

the most important thing is not perfect blood sugar control… the most important thing is to keep moving. you’re doing great!

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You didn’t mention if you knew what your IOB was. IOB is probably the most important thing to know. If you use a pump, it should tell you, but be aware many systems do not include basal insulin in the IOB calculation. That can be seriously misleading if you’re doing strenuous exercise. Since your glucose went down, then came right back up, I’m guessing you had IOB, which caused the low, then the snack kicked in too late to be offset by the exercise. You might try Christel Oerum’s Diabetes Strong blog. She has a lot of tips and a spreadsheet you can use to track your experimenting. https://diabetesstrong.com/fit-with-diabetes-challenge-cardio-workout-3/

Thank you! Definitely didn’t have insulin on board as I ate at 11 am and didn’t walk until 4:30.

I’ll try the lower temp basal 45 minutes before to see if that helps too.

Thanks for the advice

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Mike! Thanks for the suggestion with christel. I’ll check it out. I’ve read some of her other stuff and it’s always super helpful!

Back when I used temp basals (I use the Control IQ now), I would use at least a 50% reduction and if I could get it 30ish minutes beforehand that was good. Now I set CIQ to exercise mode as early as 30 minutes before. I then will make sure to eat about 15g of carbs before I set out, then I will constantly eat carbs while running to prevent lows. This seems to work for me, but you will have to do some trial and error with your level of activity and nutrition needs. Post exercise, I need to increase my rate to almost double for the following hours.