For a long time, I’ve been trying to figure out that “perfect” plan around carbohydrates, my insulin and my blood glucose level for training and racing on my bike. There are many variables that I have to consider as part of a plan and some of them aren’t related to my Diabetes, but certainly, need to be considered.

Sometimes I do get it wrong and I’ll admit there have been a number of times where I’ve had to cut a training ride short or pull out of a race because I haven’t managed to get the ducks lined up in a row when it came to my Diabetes.

While Diabetes is always a balance of insulin, carbohydrate intake and physical activity, the need to get this balance right during my training and racing is especially important as if I get it wrong, things can turn bad very quickly.

Diabetes Treatment Triangle

Diabetes is a balance of insulin, (Meds) food intake (diet) and exercise. Image attribute:

For now, I’ll aim to write out a typical plan for a ride or race and explain how I might alter each component.

Basal rates

Not long after starting on an insulin pump I asked my Diabetes nurse educator about how best to adjust settings on my pump for physical activity. I was given a “rule of thumb” which I still use now, with some tweaks depending on the type of physical activity. The rule of thumb is:

  • For the physical activity drop the basal rate the pump is giving my using a temporary basal rate to drop by a certain percent. Personally the amount I reduce my basal rate by varies from 15-40%
  • Start the reduction of the basal rate at least one hour before physical activity. The reason for this being that insulin takes a while to finish working, so a reduction needs a while to take effect.
  • Continue the reduction of the basal rate for 50% of the duration of the physical activity after the activity. So if the physical activity lasts for 2 hours, the basal rate reduction lasts continues for 1 hour after the activity.

This approach usually works fairly well for me is something that I always use as a starting point for physical activity. The percent by which I reduce the basal rate depends a lot on the type of riding I’m going to do.

Carbohydrate intake

Compared to some people, I quite possibly eat like a horse.

A number of years ago (I’d have to actually go and hunt down details of when it was!) I spent time with a dietitian working out a nutrition plan for a bike race which I largely stick to now. Based on my body weight at the time, it was calculated that I would need to consume around 60g of carbohydrates per hour. For the event I had spoken with the dietitian about, this worked for me. Way back then I didn’t have a continuous glucose monitor (CGM) so I can’t honestly say that my blood glucose level was within an acceptable range for the whole event, but before the race and then after the race my levels were good.

Now that I have a CGM, I can observe what impact this nutrition plan has on my blood glucose level and it still works well for me.

I always carry a few different types of food with me. Usually, I have on my bike, in my cycling jersey pockets or at least nearby:

  • A carbohydrate drink. This is made up from a concentrate and I usually mix it so that there is 70-80gm of carbohydrate in a bottle
  • Carbohydrate/energy gels. These have about 22gm of carbohydrates in them and some have caffeine. Because… Caffeine
  • Muesli bars. These are just there as a solid food option and generally have around 13gm of carbohydrates in them.
  • Pure glucose. Just in case everything turns to crap and my level goes too low.

Between the above options (aside from the pure glucose) I try to consume around the ideal number of 60gm of carbohydrates per hour. Sometimes if I know there’s a section of a ride or race where I will be expending more energy I will eat a bit more in preparation.

I usually also have a bottle of water on the bike or accessible for when I don’t need as many grams of carbohydrates available to me.

Blood glucose level

Speaking of using a CGM… This makes physical exercise including training and racing, so, so much easier. Using a CGM to see my blood glucose level in close to real time and the effect that all of these variables are having on it is just fantastic.

Before I start a training ride or race I will usually run my blood glucose level a bit higher than what is probably considered ideal. The reason for this being that at the start of a race I may expend a little more energy than I may have planned for and having my blood glucose level a touch higher means I won’t go low. I also know that I can change my nutrition plan while training or racing so that I am consuming fewer grams of carbohydrates and can drop my blood glucose level.

Changing it up

Earlier in this post, I mentioned that Diabetes is a balance of food, insulin and exercise. Sometimes I need to change one or more of these things in order to keep good control of my Diabetes. I might have to eat more or less food or adjust my insulin doses in order to get through a race or training ride.

So does this always work?

…No. Hell no. But when it doesn’t, I always spend time trying to figure out why things went wrong.

Do I manage to always figure out what went wrong? No. But I do most of the time. The times when my plans don’t go right can be frustrating as hell. There have been four letter words spoken. There has been anger. There have been times when I’ve lost my shit because things have gone so badly I’ve had a race or training ride written off and I’ve just had to stop. Sometimes I just don’t quite get the variables right. Or there are some variables which I haven’t considered and might have been out of my control.

But I keep trying. I learn from my mistakes and try not to think of them as failures, just lessons.

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