Bicycling Type 2 on MDI

Since I started MDI I have had problems trying to figure out how to do longish bike rides say 2+ hours. Even light pedaling on a DeskCycle would start my BG dropping at 15 minutes.

For years I have split my Lantus dose into two, 2/3 at night and 1/3 12 hours later. I’ve been having a steep ramp upwards after the midday meal, no matter what I ate or the Humalog dose. What fixed that is to divide the Lantus into thirds. 1/2 in the afternoon and 1/4 at waking, the remainder before Lunch. This has really given me a fairly flat curve BGwise.

I am going to do a group ride with my friends next week. This morning I held off on the Lantus dose, did Humalog, ate breakfast and road for an 1:20 using Zwift. BG started at 100mg/dl dropped to 79 in 30 minutes, I ate a Kind nut bar (9g carb) and continued riding 15 minutes later BG dropped to 77 and I ate 4g glucose. BG began rising to 87 at the end of the ride.

Part of the problem I think is that my beta cells are not completely worn out and do produce a bit of insulin. I think I will try this again eating the Kind bar first before BG goes down. Then if needed use glucose tabs or Jolly Ranchers. Our group ride usually has a stop in the middle so will probably eat another nut bar.

Any advice would be appreciated. I love to ride, solo and with my friends and I haven’t done a group ride for a year.

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I totally ditched the Lantus a few years back due to the number of lows it was giving me much to the dismay of my endo. Using only Humalog and armed with a CGM I keep my A1C in the low 5’s and very little standard deviation. My endo always asks me how I am able to keep my BG mostly flatlined and I just have to keep telling her that happened as soon as I discontinued Lantus.

@CJ114 I have tried reducing the Lantus dose but I end up with high BG dawn phenomenon and Feet on the Floor. I suppose I could do a Humalog correction while in bed but don’t really want to.

If I get Dawn Phenomenon (rise of more than 20 points in the early morning) it is because I ate too many carbs and proteins the day before and when I weigh myself in the morning, I will have gained at least .3 lbs. If I did over eat, I do take a Humalog shot before going to bed and if needed take another at 4 AM. This is why I only eat OMAD (One meal a day) unless entertaining or being entertained and need to eat dinner.

If you are on a CGM you should be able to easily fine-tune this for your circumstances. If you are on fingersticks, it can be done but very difficult and probably not worth the time and effort and cost of all those daily strips.

Realistically when you are not on a pump and your basal is somewhat long-acting (like Lantus), the best bet is going to be 2 things:

  1. Try and time your rides about 2 - 4 hours after eating so that you do not have a lot of insulin left in your body, When you eat and then ride right away, you have the Humalog in your body and the food in your stomach. But what does your body do? It slows your digestion because it wants to prioritize the muscles in your legs doing the work. Digestion is secondary at that point. So if you take insulin and food, the food is slowed and you end up with too much insulin at the time because the food is not getting processed as quickly. Digestion is also slowed when you become dehydrated, and that ends up meaning - too much insulin!

  2. The other thing to do is feed the basal on your rides! It just takes time to figure out how much you need to eat. You have to be pre-emptive. Like you can’t wait until you are low. If you are at 90 and dropping, you gotta eat. How much you need depends on a thousand things, like how hard you are working, how hard you have been working in previous days, how much you have eaten, etc. So these things take practice.

But on the plus side of things, eating carbs while riding is great fuel for your body. You can go a lot harder and longer when you are supplementing with carbs. Did you know that depending on their weight, riders in the Tour try to aim for up to 90 grams of carbs per hour while on the bike?! (But for mortals, ideally it’s only 30-60 grams per hour.)

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I prefer Clif Bars and for emergencies HammerGel

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@Marshy I’ve never tried Cliff Bars. Which to you recommend. As to HammerGel I would use the Apple Cinnamon when on long rides. This is before I started MDI. They seemed to give me a long slow sustained BG without spikes. My local bike shop doesn’t have the single use packs any more. I’m thinking of ordering the bottle and flask. Looks like it is more affordable.

Anyway thanks for the tip, Marshy.

REI sells all the different carb gels and they sell them in singles and boxes.
I prefer GU, but I’m pretty sure I’ve tried them all.
The cliff carb gels have coffee flavor, and you can get the cliff bars there too.

I don’t do well with bars though because it feels heavy in my stomach.

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@Timothy Looking at the ingredients of GU gels I really don’t want fructose and not sure about medium chain triglycerides. Fructose tends to increase serum triglycerides not sure about dietary triglycerides. High triglycerides have been a problem for me in the past and perhaps drove me into type 2 diabetes. I don’t see either of these ingredients in Hammer Gels except concentrated apple juice will have a bit of fructose.

As to REI, the closest store is 100 miles south or west. If I have to order I can do it straight from GU or Hammer. Cliff bars are available in every convenience store around here.

I understand about having a heavy weight in the stomach. If you are willing to read a story from when I was able to have good BG with diet and exercise - here goes.

I was doing a night commute 25 miles when working the midnight shift once a week. Some weeks I would take the scenic long route home. It was 16 miles to the next town and another 22 miles to my home. That leg had a great descent from a high ridge to a low and of course you had to climb out of it.

There was a restaurant in that other town. Sometimes I would stop for a couple of biscuits and coffee. This one day I stupidly ordered an omelet. I swear it was made with 6 eggs. I was starving.

I get back on my bike and 20 minutes I’m sliding down into that hole. It was pure joy. Then I had to crank back up. That omelet was growing heavier and bigger with every turn of the pedals. I thought I was going to throw up. (I hate throwing up!).

Anyway I managed to get home slowly on those more gently rolling hills. Never again, once was the lesson of a lifetime.

As you are probably already aware, sugar is 1/2 glucose and 1/2 fructose. (Sucrose is composed of one glucose monosaccharide and one fructose monosaccharide.) So anything that lists “sugar” will end up giving you some fructose.

But Transcend gels are straight-up glucose (D-glucose), and not sugar.

They each have 15 grams of glucose. These are the fastest things you can get. And they are also easy to eat one-handed, because you can tear off the opening tab with your teeth if you are riding.

Yes I am aware of the use of fructose. They use fructose, not high fructose corn syrup which is a concentrated version.

I prefer it because well it comes from fruit and it slightly more complex. It needs to be broken down and therefore hits more slowly.
Fructose also has a stomach settling quality. Eating anything while exercising makes me feel a tiny bit queasy.
Someone suggested Gu to me and it really goes down the easiest.

Apple sauce packets w the screw top, are also really good but when they get warm they become really horrible.

@Eric2 If i just want glucose I have a bottle of Karo light corn syrup. That is pretty close to 100% glucose. Very cheap and I can put it in a Hammer gel flask. By the way, Sucrose is a disaccharide, a molecule made of one molecule of glucose and one of fructose. High fructose corn syrup used in foods and beverages is a solution of two saccharides generally 55% glucose and 45% fructose.

The Hammer Gels use Maltodextrin and Apple juice concentrate and grape/rice dextrin as the 3 carbohydrate sources. The on fructose would be from the apple juice concentrate. Dextrins become glucose.

This chart is a good comparison of energy gels.