Skip to content

Overstuffed And Underpowered


I hear it time and time again, during training rides, before and after races, that an athlete was just trying to eat more, get more calories in, or “force” their body into processing more calories because more fuel must equal more power! If only the human body worked that way.

The issue of tinkering with overconsumption, (that’s what it is when you’re making your stomach upset because you’re taking in too much fuel) is taking a simple notion that less weight must make hills easier, and more fuel in the tank means you can use that fuel and go faster as well. If only the body worked like a muscle car—where the bigger the fuel injectors are and the more air you put in the engine, the bigger the boom. A bigger boom is directly correlated, in combustion engines, to faster lap times, better acceleration, more torque, stuff like that.

Except for the inconvenient truth that, in practice, many people climb hills faster—even with more weight on their body and bike, and consuming the lower limit of calories makes for less stomach distress, fewer bathroom breaks, and oh yeah—more efficient fuel burning for faster times.

In case you’re still not convinced, I’ve collected a few articles that ponder and even go so far as to test “over-fueling” so you don’t have to.


The first case was in a sample group of ultrarunners that while small, is exactly in line with what we’ve seen over the course of many fueling consultations when athletes either DNF’ed or missed their PRs by large margins.

In short, mountain marathon runners were advised to consume up to 120 grams per hour of carbohydrates (~480 calories).

Luckily only 3 out of 26, or 11.5% of the marathon runners DNF’d as a result of gastrointestinal distress. A few great quotes from the study:

“…the 7 finisher participants in the 120 g/h group didn’t report serious problems…”

“We saw that major races in the world (Giro de Italia, Tour de France, Hawaii IRONMAN, Berlin Marathon) were won using similar methodologies…”

“It is important to note that, in theory, higher intakes than 90 g/h could have beneficial effects as we had seen higher oxidation rates with higher intakes…”

You may read the full study and follow up articles here:

The reality is that even with actual athletes feeling awful, above 1 in 10 were unable to finish the distance and at best, unrepeatable anecdotal evidence was gathered.

The study also suggests that “it is possible to take in larger amounts of carbohydrate during real events,” possible yes, but is it better or faster for real athletes all the time? By any stretch of the imagination, or tests of any capacity including their own, that answer is no.

Hammer Nutrition recommends much less than this study suggests. You can comfortably fuel with 120–180 calories per hour, i.e., 1.5–2 servings of Hammer Gel, which is roughly 25–44 grams per hour. Read our book SOS: 5 Secrets of Success for more information.

The other clear and simple fallacy suggested is that “further nutritional training is required to manage gastrointestinal comfort.” Now I don’t know about you, but considering I haven’t withered away to nothing, I’d say that my calorie consumption is at the point where my body usually processes the food that I eat with little hesitation. The idea that forcing your stomach to process more fuel, in hopes of using more calories per hour to go faster, is a hopeless method of convincing you to buy more products you don’t need, and often achieves the opposite result—you go slower.

So, if you as an athlete want to achieve poor results and finish fewer races than ever before, you should of course stuff yourself silly!


It amazes me how many endurance athletes and “scientists” are fascinated with force feeding and trying to make their body “adapt” to consuming far far too many calories during exercise.

The evidence is clear from scientific studies, to talking to amateurs and pros alike—less is best, especially when you want to make the most power, and especially when the heat is intense.

This is a great time to disregard every article, podcast, or video that suggests that you can and should attempt to “train your gut” by stuffing yourself full while training and racing. Your stomach, bladder, wallet, and training partners will thank you.

Viribay A, Arribalzaga S, Mielgo-Ayuso J, Castañeda-Babarro, Seco-Calvo J, Urdampilleta A. Effects of 120 g/h of Carbohydrates Intake during a Mountain Marathon on Exercise-Induced Muscle Damage in Elite Runners. Nutrients 12(5), 1367, 2020. doi: 10.3390/nu12051367.

OTHER SOURCES (suggests up to 90 grams carbs/ hour) (suggests high carb input, and mix of simple and complex carbs)

Leave a comment

Please note, comments need to be approved before they are published.

All Endurance News Weekly >

You have no items in your shopping cart.
Click here to continue shopping.