The Dazzlingly Incompetent's Guide to Fueling

Editor's Note: This title is in reference to myself, who has managed to mess up the below points in more races than I care to admit. My former coach labelled me "dazzlingly incompetent" for managing to self-sabotage a race that frequently; hence, a guide for us!

Here’s your crash course in things that you might want to consider adjusting, if you’re having issues while targeting higher carb intake rates during training or racing. There’s a lot to manage, but once you get it right, it becomes an intuitive process of listening to your body and responding in stride.

If You're Bonking


Consume more carbs. You’re underdosing carbs for how long you’re training.

If you’re getting shaky, irritable, or hungry


Consume more carbs! You may be hypoglycemic. Carbs are the antidote.

If You're Cramping


Consider more sodium, and more fluid, but never more of the latter in proportion to the former. Don’t dilute your electrolytes just because you need more water! And consider more carbs. Sometimes cramps are simply more fatigue-related than electrolyte related, and carbs are a powerful combatant to fatigue.

As a reminder, we covered off a lot of this here.

If You Feel Like You Can't Take More In


Use liquid carbs only. Eliminate solids. Especially things that aren’t gels and chews. But those can be trouble too, if you’re not dialed in on the rest yet. Just too high of a risk of hitting your gut with high carb concentration in a precarious state.

When In Doubt, Drink More


This matters for two reasons.

1. You need to stay hydrated for your gut to work properly.

2. Separate from being hydrated, you need to have water in your gut for carbs to absorb. Not consuming enough water with your high level of carbs is a recipe for guts revolting. The overall solution in your gut matters for both absorption and comfort. 100 grams of carbs per liter = 10% solution concentration. Most folks can tolerate 12-18% if they’re also well-hydrated. At the end of a race, maybe bump it down to 8-10%, more fluid needed! At the end of the day, fluid needs should be driven primarily based on hydration needs (how much you are sweating). If you manage that, and don’t have ridiculous instantaneous dumps of ultra-high-concentration stuff (gels & chews) into your gut, you’ll be fine on this front.

When In Doubt, More Salt


This matters for a dozen reasons, but here are three.

1. It’ll increase your thirst. See number 4, above.

2. Sodium helps carbs absorb in your gut.

3. It’ll help reduce urination (don’t worry, you won’t get the ocean water effect, and if you think you are, you’re not. You still need more salt. It would take tablespoons of sodium to get the ocean water diuresis effect.)

Manage the Glucose:Fructose Ratio


Target between 2:1 and 1:1. 1:1 is probably fine. Closer to 1:1 is probably better than 2:1. Sugar = 1:1. It’s one molecule of glucose:fructose. Maltodextrin & fructose, is gram for gram 1:1. It’s another way to get 1:1 glucose:fructose because maltodextrin is a pure glucose source. Here’s 60 seconds of slam dunk maltodextrin info:


No Other Carbs


Michelle (my wife) did a neat video on monosaccharides and what they mean for endurance athletes.



No time to watch? Don’t use galactose. Don’t use anything that doesn’t present just glucose and fructose.

Avoid Complex Carbs (Except Maltodextrin)


Not all complex carbs are created equal. First, a primer here: complex carbs are any carbohydrate that is composed of 3 or more monosaccharide units. (ie. single sugar molecules). Stick 3 of them or 20 of them together and you have a complex carb. Some “complex carbs” also known as “long chain” carbs. They are quite rapid to digest because breaking them down in your digestive tract is not a rate limiter for absorption to your bloodstream from the lining of your gut. It just happens so fast, that they are essentially the same as simple sugars, physiologically.

The advantage to using them is that they lower the osmolarity of the solution in your gut, which is a good thing when trying to let your gut do its thing during exercise. Too many molecules in solution is called a hyperosmolar solution. Stomachs and intestines don’t like that. But, they’re not as bothered by it as we once thought, so most of the “osmolarity” and “isotonicity” related marketing these days is just that: marketing.

That said, there absolutely are many complex carbs that do NOT sit well or digest quickly through your gut. For example, consuming waxy maize starch is just a recipe that hinders your ability to consume more per hour. “Slower to digest” is code for “going to cause GI issues if you consume at 80-130 grams per hour.”

So, if you’re concerned with maximizing performance and minimizing gut issue risk, stick with maltodextrin as your non-sugar carb source.

If You're Hungry


You're underfueled. More carbs are the solution.

If You're Having Stomach Issues


This is especially true if it is happening later in your training or racing. You're either:

1. Not consuming enough water with your carbs.

2. Mismanaging glucose:fructose ratio, usually too high on glucose for experienced or “old school” athletes.

3. Consuming disastrously too much sodium. (ie. you used a tablespoon, not teaspoon). Or:

4. Consuming too many carbs per hour for your hydration status or thermal stress. Usually this is caused by delays in fueling and hydration implementation earlier in the activity. Start earlier. Start fueling and intaking fluid with the first step or stroke (arm or pedal, you choose) next time.

If You're Confused By What's In a Product


Some handy definitions.

Dextrose = glucose.
Fructose = fructose.
HFCS = ~50:50 glucose:fructose
Maltodextrin = glucose.
Sucrose = 50:50 glucose:fructose
Maple syrup = 50:50 glucose:fructose, but with some other stuff in it.
Tapioca syrup = glucose
Honey = 3:4 glucose:fructose and math is hard. Avoid, unless using a product alongside it that you know is overdosing glucose.

For products containing maltodextrin as the only long-chain carb, plus other sugars, you can check the nutrition label and get a better handle on what’s actually being sold to you. First, check total carbs. Then look at added sugars. Then review the ingredients list. Use logical reasoning. Not sure how this works exactly? Stay tuned.