The Athlete's Guide to Carb Loading: How to Peak for Race Day
By Carson Beckett
Writer, Pro Cyclist
What if the difference between a subpar race and a breakthrough day isn't just your training, but how you fuel in the final week? This is how pros fuel for peak performance when it matters most.
The Pre-Race Paradox Every Athlete Faces
You've put in the months of training. Your fitness is dialed. Race day is one week out, and suddenly you're stuck between two competing needs: maximizing your glycogen stores while maintaining that lean, fast feeling that months of training have built.
Most athletes get this wrong. They either load up the day before with a high volume of food (hello, race-day gut bomb) or they panic-restrict calories as their training load drops and show up depleted. The pros know there's another way.
Why Traditional Carb Loading Fails Athletes
The old-school approach of pasta parties and pancake mountains worked fine enough, until we learned better. Today's endurance events demand a more sophisticated approach. One that sets you up for success by deliberately “stocking” the body up over time. Traditional approaches usually involved an acute and drastic increase in carbs the day or night before, which can lead to bloating and water retention. And if I may add, probably discomfort, pee wakes, and poorer sleep.
The Elite Taper Protocol
As we discussed in another article here, there’s a better way to do it. So, how do you properly “carboload” in the days leading up to a key event? You do it gradually over time – just like your training taper.
The process is really crucial in the final 48-72hrs, but can be supported by backing up your fueling plan to nearly a week. Here’s how.
Days 7-5: Balance
You’ll cut training volume down (you already knew this)
Naturally, less training = less total calories/energy expenditure
Maintain protein at 1.2g per kg bodyweight to preserve muscle and power
Here's the key: Keep carbs at 5-6g per kg bodyweight, but shift the timing (ie. breakfast, training fuel, and recovery meals are your “heavier carb”)
Days 4-2: Strategic Increase
This is where most athletes mess up. Instead of increasing just carb quantity, pay attention to carb quality and timing. Since your training is dramatically reduced, the timing of higher carbohydrate doses is important for optimal absorption and limiting the insulin/ blood sugar rollercoaster.
Large % of your carbs are consumed within a few hours post-workout [1]. In the early post-exercise period (0–4 h), glycogen depletion provides a strong drive for its own resynthesis.
Switch to easily digestible sources: white rice, simple grains, starchy veggies, etc. (yes, higher glycemic foods will be part of this equation).
Reduce high-fiber foods that can cause GI distress [2]
Target 8-10g per kg bodyweight only on these three days [3]
Leverage sports nutrition (like high-carb gels and drinks) during sessions to boost carb intake
Day 1: Top Off the Tank
Return to normal carb intake (5-6g per kg)
Focus on familiar foods only, your “go-tos”
Last meal ~12 hours before race start
Morning of / Pre race: ~3hrs before, 2-3g / kg bodyweight (this is not a hard rule, just be mindful to not over do it).
How to Use Sports Nutrition
The taper period is one where athletes can actually benefit from using sports nutrition to aid in carbohydrate loading. One way to do this is by bolstering your training with high carb fuel.
For example, continuing to have a high-carb drink mix on those shorter prep workouts. Following workouts with a recovery shake. Snacking on energy bars around training as an easy way to get 30, 40, or 50 g more. Often, staying balanced with getting enough carbs while not feeling overwhelmed at your meals is easier when you can leverage sports nutrition to get those extra carbs. You can use them as a dessert the night before or topping off when the race-day nerves hit.
What Carb-loading Does
Based on peer-reviewed studies, athletes using strategic carbohydrate loading protocols demonstrate measurable advantages over those “old school” traditional approaches:
Increases muscle glycogen stores: Increases glycogen content by 20+%, providing more available fuel for endurance exercise.
Delays onset of fatigue: Helps prevent that dreaded “bonk” by maintaining glycogen stores deeper into long efforts.
Improves endurance performance: Enhances time to exhaustion and elevates performance, especially in events longer than ~90 minutes.
Maintains blood glucose levels: Reduces reliance on circulating glucose early in exercise, stabilizing energy and brain function.
Lowers perceived exertion: Athletes feel less fatigued and can maintain higher intensities more comfortably.
Supports day-to-day recovery: Higher glycogen stores aid in faster replenishment/recovery between long training days or race stages.
Reduces post-exercise immune suppression: Helps regulate cortisol and immune function during heavy training blocks or long events.
The Foods That Make or Break Taper Week
Green Light:
White rice, white breads, oatmeal
Bananas and low-fiber fruits
Sweet potatoes, potatoes, starchy veggies
Maple syrup, honey, etc.
Pastas (with consideration)
Red Light:
Anything high-fiber (even "healthy" options) [2]
New foods (save experimentation for training)
Excessive fruit (fructose can cause GI issues) [4]
Large portions of protein or fat with carb meals
Alcohol (disrupts sleep, which disrupts glycogen synthesis [5]
Application: What Your Race Week Looks Like
This isn't set in stone, but rather a good template to model your week after alongside training.
Monday (Day 7): Last hard workout, normal eating plan
Tuesday (Day 6): Easy movement, focus on post-workout carb timing
Wednesday (Day 5): Light workout, begin quality carb focus
Thursday (Day 4): Light workout, peak carb intake (8-10g/kg)
Friday (Day 3): Opener workout, maintain high carb intake
Saturday (Day 2): Restful day, moderate carbs, early dinner
Sunday (Race Day): Light or standard breakfast, race nutrition only
The Bottom Line
Taper week isn't about eating more – it's about eating smarter. The athletes who show up feeling light, fast, and fully fueled understand that glycogen storage is a precision game.
Your months of training have built the engine. Don't sabotage it with a week of poor fueling choices. Trust the process, stick to familiar foods, and let your fitness do the talking on race day.
Resources
1: Burke, L. M., van Loon, L. J. C., & Hawley, J. A. (2017). Postexercise muscle glycogen resynthesis in humans. Journal of Applied Physiology, 122(5), 1055-1067. https://doi.org/10.1152/japplphysiol.00860.2016
2: University of Illinois. (n.d.). Chapter 3 – Carbs: The secret weapon for endurance athletes. Sports Nutrition. https://publish.illinois.edu/sportsnutrition/ch3-carbs/
3: National Strength and Conditioning Association. (2019, July). Carbohydrate loading. NSCA's Kinetic Select. https://www.nsca.com/education/articles/kinetic-select/carbohydrate-loading/
4: Wikipedia contributors. (2025, January). Carbohydrate loading. Wikipedia. https://en.wikipedia.org/wiki/Carbohydrate_loading
5: Donga, E., van Dijk, M., van Dijk, J. G., Biermasz, N. R., Lammers, G.-J., van Kralingen, K. W., Corssmit, E. P. M., & Romijn, J. A. (2010). A single night of partial sleep deprivation induces insulin resistance in multiple metabolic pathways in healthy subjects. Journal of Clinical Endocrinology & Metabolism, 95(6), 2963-2968. https://doi.org/10.1210/jc.2009-2430