Fueling Frequency vs Quantity – Why Frequent Fueling Wins for Endurance Athletes with Type 1 Diabetes
As a competitive runner preparing for the Olympic Marathon Trials—and someone managing Type 1 Diabetes every day, or any endurance athlete for that matter—I’ve had to become meticulous about energy management. What I’ve learned through training, trial and error, and scientific research is this: frequent fueling isn’t just a tool—it’s a performance strategy.
Whether or not you live with diabetes, how often and how strategically you fuel can profoundly impact your energy levels, hormone regulation, mental focus, and athletic longevity. The ONLY downside I can think of is you have to carry snacks on you all the time—but believe me, there are a lot worse things (this is also the best way to guarantee you will have friends for life by always having snacks on you, as long as your blood sugar isn’t low!)
The Physiology of Frequent Fueling
Endurance exercise demands energy—especially carbohydrates. Our bodies rely heavily on muscle glycogen and circulating glucose, but these stores are limited. When they run low, you “bonk”—a drop in blood glucose and available energy that feels like running into a wall.
By fueling every 30–45 minutes with 15–30 grams of carbs (depending on intensity and gut tolerance), we maintain more stable blood glucose, spare glycogen, and reduce perceived effort during long runs and races. Research consistently supports this and is something that I have learned as a Type 1 through a lot of training trial and error: small, regular doses of carbohydrate improve endurance and delay fatigue (Cermak & van Loon, 2013; Jeukendrup, 2014).
More importantly, this approach helps you meet your total daily fuel needs, something many endurance athletes—especially female athletes—fall short on during peak training blocks, without leaving you feeling incredibly full throughout the day, or as a type 1 especially, chasing highs from big meals and the subsequent low of a large insulin bolus. I tell my athletes that often the higher your go post-meal, the lower you will go on the backend after correcting and/or exercise. You will also feel the larger change or derivative even if not dropping to dangerous levels.
Frequent Fueling Helps You Hit Daily Nutrition Goals
Let’s be real: if you’re only eating 3 big meals per day while training 1–2 hours daily (or more), you’re probably not eating enough to recover, adapt, or perform at your best. Below is a ballpark snapshot and keep reading for a sample ‘day in the life’ meal plan.
Protein Needs
(In-Season, can increase during off-season in place of some of your carbohydrate calories)
To maintain muscle mass, optimize recovery, and regulate blood sugar (by slowing absorption of carbs and effectively lowering meal/snack glycemic index):
- Aim for 0.75–1g of protein per pound of bodyweight per day
- Example: A 150 lb athlete needs at least 110g, ideally closer to 150g
Eating protein-rich snacks every 3–5 hours supports muscle repair and keeps hunger/cravings in check. Frequent fueling makes it possible to meet this target without cramming giant portions into just 2–3 meals (Areta et al., 2013).
ADVERTISEMENT – Use Code RunTriBike To Save 20% Off Your Order
Carbohydrate Needs
(Endurance Athletes)
Even considering variations in tolerance, intensity, and duration:
- Most athletes need at least 250–300g of carbs per day, and often much more during high-mileage weeks. Note, this is a start. As someone who used to limit carbs to about 150-200 per day to control my diabetes, I was still able to perform well. However, it wasn’t until I increased this amount significantly that new levels were unlocked—insert, Olympic Marathon Trials! (Believe me, it is worth increasing insulin intake for ;))
- Carbs are your primary fuel for intensity and endurance. Don’t fear them—fuel with them.
And yes, that includes Type 1 athletes.
Carbs & Type 1 Diabetes: The Power is in the Timing
Do people with Type 1 Diabetes eat carbs?
HELL YES, we do.
I couldn’t compete at an elite level without them. The key difference is in how we time and manage our carbohydrate intake alongside insulin.
Here’s how I approach it:
Pre-run / exercise
(Note, GI = Glycemic Index. GI is a ranking of carbohydrates on a scale from 0 to 100 according to the extent to which they raise blood sugar (glucose) levels after eating. Foods with a high GI are rapidly digested and metabolized, resulting in higher fluctuations in blood glucose. Low GI carbohydrates produce smaller fluctuations in your blood glucose and insulin levels) For details on GI and a chart of GI of common foods, I like this website: https://glycemicindex.com)
- Prioritize a low- to moderate-GI mixed meal 1–2 hours before
- Me: Sourdough Avocado Toast (2 slices) and dark chocolate with coffee/cream
- Reduce or delay bolus insulin slightly to avoid exercise-induced lows
During exercise:
- Honestly, do I count exactly how many carbs per hour? NOPE. That said, I make sure I eat frequently (not just carbs, either, focusing on clean fuel). If I were to quantify it, I consume 15–30g of fast-acting carbs every 30–45 mins of lower intensity and shorter duration (<2 hours). Needs increase for runs or exercise sessions greater than 2 hours, where I increase on a sliding scale of about 30-45g/30-45 min. At its simplest: if you are hungry, it is too late. Use precursor hunger cues as your guide!
- Often with little to no insulin, depending on CGM trends and intensity (e.g. higher intensity, for me, often requires small amounts of insulin due to adrenaline blood spikes)
Post-run:
- Reintroduce carbs + protein for recovery (25–40g carbs + 20–30g protein) – protein first if BG is higher, and then carbs after an extra 15 min with a small amount of insulin
- Me: Fairlife or Kion Protein Shake and/or Chia Pudding (yogurt mixed with chia seeds, protein powder, collagen, berries, cinnamon)
- Use a reduced correction (insulin) bolus if needed, based on CGM trends – remember that glucose AND insulin sensitivity will be higher for about 3-4 hours post-exercise, often longer, with weight training.
This approach keeps blood sugar more stable during and after training, reduces the need for large correction doses, and minimizes the risk of both hypoglycemia and post-exercise hyperglycemia (Yardley et al., 2013).
Frequent Fueling = Less Stress, Better Outcomes, ≠ ‘Carb-Loading’
For non-diabetic athletes, frequent fueling mimics a low glycemic load (note load = (glycemic index x carb amount) / 100) eating pattern—minimizing glucose and insulin spikes while optimizing energy availability. It reduces the all-too-common mid-run crash or late-night raid of the kitchen. AKA, goodbye pre-race carb-loading (yes, I said it!)
For Type 1 athletes, this method limits the need for large, pre-run insulin doses that can backfire mid-workout and helps prevent extreme glucose swings—both of which can impair performance and safety. And again, goodbye carb-loading nightmares of insulin spikes and crashes!
Plus, there’s a mental relief in knowing your fuel plan is steady and reliable. You’re no longer riding a rollercoaster of guesswork. You’re executing.
Final Thoughts: The Cliché, Train Your Gut to Fuel Your Goals
Frequent fueling isn’t about eating more—it’s about eating smarter.
It’s about giving your body a steady, reliable source of energy, honoring your recovery needs, and reducing both physical and emotional stress. For athletes with diabetes, it’s about gaining confidence and control. For everyone, it’s about unlocking better performance.
Whether you’re managing Type 1, chasing a personal best, or just trying to feel strong from start to finish—fueling frequently is the foundation, and when your body is primed and ready to accept both carbohydrates and insulin around exercise.
References
- Areta, J. L., et al. (2013). Timing and distribution of protein ingestion during prolonged recovery from resistance exercise alters myofibrillar protein synthesis. Journal of Physiology, 591(9), 2319–2331.
- Cermak, N. M., & van Loon, L. J. C. (2013). The use of carbohydrates during exercise as an ergogenic aid. Sports Medicine, 43(11), 1139–1155.
- Jeukendrup, A. E. (2014). A step towards personalized sports nutrition: Carbohydrate intake during exercise. Sports Medicine, 44(Suppl 1), S25–S33.
- Yardley, J. E., et al. (2013). Managing diabetes in physically active individuals. Current Diabetes Reports, 13(3), 371–378.
ADVERTISEMENT
