Hi folks, do you have any strategies dealing with exercise one to two hours after a meal? In my experience this is one of the hardest challenges of type 1 diabetes. The typical situation for me would be that I need to go somewhere 1-2 hours after lunch or dinner, because as a Dutchman, I bike most places (yeah, I fit that stereotype 
). In order to prevent my BG from spiking, Iād need a full bolus dose, but then I inevitably go low while biking. Often I eat a ton of sugary stuff before hopping on my bike, which in many cases of course leads to a huge spike afterwards. How do you deal with situations like this? Any tips appreciated!
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I see the same inevitable bad effects. If Iām doing a lot of work (physical work) I avoid food; eating in the evening is reliable after a day of harder-than-normal exercise probably because my increased insulin sensitivity is looking for food then.
So OMAD might work but the alternative is to adjust the meal to a lower adsorption rate. Keto does that; no carbs no problem (great way to check out our basal, or not, see below.)
Keto isnāt that simple in practice because the both the protein catabolism and the fat catabolism directly contribute to our energy producing cycle (the āKrebāsā cycle, or the TCA cycle after the principle chemicals involved.)
What seems to happen is that proteins and fats both replace glucose/fructose/etc in our cellsā energy requirements and therefore our need for those goes down. Since Keto avoids carbs that works out, though I suspect a T1 on keto might need a slightly increased basal to handle overproduction of glucose from the liver.
Over the last few years and many diets Iām drawn to the conclusion that carbs-before-exercise is a bad idea and the solution is the famous doctorās solution, āWell, donāt do that.ā
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In my case, unexpected excersise after eating along with several units onboard is a guranteed low. My only suggestion is if physical activity is expected, limit the amount of IOB when starting your activity.
Easier said than done:(.
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I have this problem too. I think @Eric has talked about this in a prior thread - Iām sure he has lots of strategies.
I just make sure I have bars or candies with me while Iām riding, and start eating when I start to go low. I also carry glucose tabs but generally prefer breakfast bars / cliff bars.
I find that if I push myself I will go low faster, so as Iām going low, I might cut back on my burn - not pedal as hard. This buys some time for the bars to kick in.
Also, if you have a water bottle, you can add some of those powders to your water - basically making it sugar water.
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Hi @Boerenkool,
My general rule for exercise is to try to eat 2 hours before, and to eat complex slooowww carbs. This gives me some fuel for the activity but also minimizes IOB.
After 2 hours, most of the insulin is gone. I know some of it is still there, and it depends on how you deliver it too.
(I think injection with a syringe helps it go through faster than using a pump. Although the only pump Iāve ever used is omnipod, so I am not sure if itās the same with other pumps. But I try to inject with a syringe for meals before hard activities. For easy stuff I donāt worry about using syringes.)
The next thing is the zero basal strategy. You need to remind me of what you are using. If you are on MDI, then of course you canāt really do that. But if you are using a pump, turning off basal when you are on the bike is going to help.
Are you able to monitor your CGM while riding? If you have a watch thatās connected to your CGM, or a mount for your phone, this can help.
Give me a little background on what you are working with, your insulin regimen and so forth. That can help me come up with suggestions on how to navigate it.
For hard rides - like workouts - you want to focus on getting sufficient carbs in your meal before. That is fuel that you need for the workout.
But for easier rides that are more for the sake of travel, if you can reduce the size of the meal before rides, this also helps reduce the amount of IOB you will have.
And of course taking carbs while riding is going to be the fix for either case, hard or easy rides. I donāt believe in running up my BG before I start.
And then when you are done - bolus! Nobody tells you that. After you finish a long activity, the last thing anyone will tell you is to take insulin after you are done!
Letās start with your diabetes regimen, what you are using, etc. Give me some details on that.
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If Iām understanding correctly your bolus for lunch or dinner is what you would normally use, but a postprandial ride causes a hypo.
If you are using a pump, a lower basal rate profile would be helpful, If MDI this takes some creative manipulation. When I was on MDI using Lantus for Basal I had to split the dose. My riding at that time was mostly midmorning, I would do 2/3rds at night and 1/3rd in the AM, but after the ride. With Tresiba which the dosage overlaps the last one, spliting the dose is probably not an option.
As to loading up with a lot of sweet carbs, I think that is going to cause problems. Try a snack of mixed fat, protein and carbs, such as, mixed nuts, cheese and 10g carbs of bread. This is something that should give a slow long flow of glucose.
You are going to have to find what works best for you. I live in a rural area and most of my riding is recreational. Before I retired I would ride once a week 40 km one way.. This was at 10PM. Sometimes I would take the 75 km scenic ride home. At the haflway point I would have a light meal at a restaurant.
A story about that and a caution, one morning I got to the restaurant starving, not hypo, just hungry. I ordered an omelet. I sware it must have been 4 or 5 eggs plus the vegs in it. In the second leg of this ride there is a pair of ridges. A great descent, but what goes down must go up. That omelet wanted to leave me on the climb.
Iām going to suggest a book, āThe Athleteās Guide to Diabetesā by Sheri Colberg.
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2 hours after eating, lots of bolus insulin remains, and the increased insulin sensitivity from exercise causes a low. Iād try using afrezza for the meal bolus because it will be gone before the exercise starts. Or just eat lots of carbs during the rideā¦.
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Hi @Eric,
My setup is a 780G pump with Novorapid/Novolog and an FSL 2 glucose monitor. During daytime I have a pretty steady basal rate of .5 U/hr. Most of my rides are only 1-6 km (~ 0.6 - 4 miles), but frequently even 1 mile can make my BG crash. I rarely lower my basal for these rides, because in my past experience that would just be too little, too late. But maybe in combination with something else it might help?
The āworstā scenario is when I get invited for dinner, because then Iām not in control of what gets served.
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Correct, otherwise Iām unable to avoid a postprandial spike before the ride.
Afrezza never made it onto the European market. I donāt know why.
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Another possible thing to try is to reduce the meal bolus say 10% and see if that improves things. I know some of us like to keep BG as normal as possible but going into the ride a bit high might do the trick.
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If you do a zero basal while riding, and start it a little bit before your ride begins, it can help.
For example, maybe 30 minutes before you start? Maybe 45 minutes? You have to try it out and see what works for you.
That will definitely help.
And the other thing is to make sure you have rapid carbs that are easy to take. If you have a water bottle on your bike, thatās easy. Or maybe some of the gel fuel products made for exercise.
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I think its really different between 1 and 2 hours.
This weekend I did a 3.5 hour gravel race which burned 3500 kj (~kcalories) according to my powermeter. Breakfast we 70g of carbs, I bolused as normal and turned off insulin about an hour before the start. Levels were fine and I didnāt need to start supplementing carbs until 1/2 hour after the start.
If the race had started only 1 hour after breakfast I would have needed to compromise between starting closer to 200 or immediately downing carbs to fight off the impending dip.
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I struggle with this. Iām on MDI, Novolog/Novorapid with Levemir. Iām better off cutting my mealtime bolus, possibly in half, and taking more bolus later as needed. If I didnāt have that foresight, and took my normal bolus amount, I need to have quick carbs on me all the time - smarties (dextrose based candy) and or sugared soda.
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Iāve never mastered this, so Iām looking forward to tips from others. If I know Iām going to be active, I have the normal meal bolus and reduce basal anywhere from 30% to 75%, depending on expected exertion, for 1-2 hours beforehand (I donāt respond to a basal change for at least an hour). If itās unplanned activity, reduce bolus the same and enjoy the excuse to have a couple of biscuits ā not a lot of carb but hopefully enough to prevent going too high or too low (he wishes!). Zero basal for me is only an option if Iām already dropping more quickly than normal.
Back in the days when I was a hardcore hiker/cyclist, my CDE told me this. I vaguely remember something about āafterburn,ā strenuous activity making the BG rise later on.
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