You’re standing at mile 20 of your aim marathon, legs feeling surprisingly contemporary, when abruptly it hits—that acquainted fog, the heavy legs, the whole lack of energy.
You’ve hit the wall. Laborious.
In the meantime, the runner subsequent to you, who you’ve been pacing for the final hour, surges forward like they simply began the race.
That’s not stunning should you’ve been working for any variety of years.
However right here’s what would possibly shock you: the carb loading recommendation you adopted could be many years outdated, and really working in opposition to you.
The analysis on carbohydrate loading has advanced dramatically over the previous twenty years. What labored for marathoners within the Nineteen Sixties isn’t essentially what fashionable science tells us will optimize your efficiency in the present day.
The Traditional Protocol: The place Carb Loading Began (and Why We’ve Moved On)
Let’s have a look at the place this complete carb loading factor got here from.
Again within the Nineteen Sixties, Swedish researchers found you possibly can double your muscle glycogen shops with a strategic food plan manipulation [1].
Think about storing twice as a lot gasoline in your muscle tissue earlier than a race.
The catch? The unique protocol was brutal.
Days 1-3: Beat your self up with arduous coaching whereas consuming virtually zero carbs.
Days 4-7: Load up on carbs (60-70% of energy) whereas tapering.
British marathoner Ron Hill used this method to win gold on the 1969 European Championships [2], and abruptly everybody needed in on the key.
However right here’s what they didn’t promote: the unwanted effects had been terrible.
The high-fat, low-carb part left runners with critical digestive points.
That arduous exercise every week earlier than race day? It compromised restoration if you wanted it most.
And the carb-free days felt like torture (regardless of how powerful we’re, most runners discovered this protocol completely depressing).
The excellent news? We’ve discovered you don’t want the struggling.
Analysis within the following many years [3] confirmed you possibly can obtain almost the identical glycogen ranges with out the depletion part.
Even higher: well-trained athletes might max out their shops in simply 1-2 days as an alternative of a full week.
What’s Really Taking place in Your Muscle groups
Right here’s what’s really occurring if you carb load.
Analysis by Dr. Jørgen Jensen on the College of Oslo [4] revealed {that a} single bout of glycogen-depleting train triggers sustained activation of glycogen synthase and AMPK, together with elevated expression of proteins like GLUT1, GLUT4, and hexokinase II, the mobile equipment that determines glucose uptake capability.
Consider it like this: if you deplete your glycogen shops by way of train, your muscle cells mainly panic and improve their gasoline storage capability.
They enhance the variety of “doorways” (glucose transporters) that permit carbohydrates into the cell and ramp up the enzymes that convert these carbs into storable glycogen.
The numbers are spectacular.
In educated and well-fed athletes, muscle glycogen focus is roughly 150 mmol/kg moist weight following relaxation, however can attain supercompensated ranges of 200 mmol/kg moist weight after a number of days on high-carbohydrate diets, that’s a 30-40% enhance in gasoline storage.
Every gram of glycogen is saved with 3 grams of water, which explains the 1-2kg weight achieve you would possibly discover.
The Fashionable Method: Easier and Science-Based mostly
The difficulty is that we now know you possibly can obtain the identical glycogen supercompensation with out all of the struggling.
Fashionable analysis reveals [5] there’s no have to deplete glycogen shops earlier than loading, and carb loading for simply 24-36 hours is satisfactory, particularly for educated athletes.
For many leisure marathoners, the candy spot is 2-3 days pre-race.
For extremely educated athletes, 1-2 days might suffice.
Information from a number of research [6] reveals the goal is 8-12 grams of carbohydrate per kilogram of physique weight day by day in the course of the loading part.
In case you’re a 70kg (154lb) runner, meaning 560-840g of carbs per day.
To place that in perspective, it’s roughly 14 bagels price of carbohydrate (not a advice, simply so that you perceive the magnitude!).
As an alternative of three large meals that depart you feeling stuffed and depressing, unfold your carb consumption all through the day with fixed snacking.
Analysis printed within the Journal of Utilized Physiology [7] reveals you need to give attention to quick carbohydrates, refined sugars, white rice, and starches that digest simply.
White bread, pasta, potatoes, and rice needs to be your go-to meals.
Save the brown rice and complete grain bread for after the race.
Right here’s what’s completely different from the traditional protocol: NO depletion part, NO excessive low-carb days, a shorter loading window (2-3 days vs. 7 days), and far simpler in your digestion and restoration.
Does Race Distance Really Matter?
Right here’s the place many runners go unsuitable: they apply marathon carb loading methods to each race distance.
Let’s be clear about this.
For 5Ks and 10Ks: Skip the carb loading totally.
Your regular glycogen shops can gasoline 90 minutes of working, which implies most runners by no means faucet out throughout these shorter races.
Simply eat usually, keep hydrated, and have an honest race-morning breakfast.
For half marathons: It will depend on your end time.
In case you’re crossing the road in underneath 90 minutes, you most likely don’t have to carb load.
Working 1:45 or slower? Contemplate a modified 2-3 day protocol with elevated carbs within the closing 24 hours.
For marathons: That is the place carb loading turns into non-negotiable.
The analysis reveals a 2-3% efficiency increase [8], and one examine discovered correctly carb-loaded marathoners ran 14% sooner than those that didn’t.
That’s doubtlessly 20+ minutes for a lot of leisure runners.
The underside line? Match your fueling technique to your precise race calls for, not what you see elite marathoners doing.
The Sensible Sport Plan for Busy Runners
Let’s make this sensible.
You’ve obtained a full-time job, household obligations, and a race in 3 days.
Right here’s precisely what to do.
Days 3-2 earlier than race: Preserve your straightforward working quick and lightweight.
Enhance the carb proportion at every meal whereas lowering fats and protein.
Analysis reveals [9] you need to make your greatest meal lunch the day earlier than, not dinner, which permits correct digestion and glycogen storage relatively than leaving you with a full abdomen on race morning.
For race morning timing: a examine demonstrated you need to use 1g carb per kilogram of physique weight for every hour earlier than the race.
In case you’re consuming 3 hours out, that’s 3g/kg.
Two hours out? 2g/kg.
Prime off with a gel 10 minutes earlier than the beginning.
What about liquid energy? Discipline-based analysis [10] suggests sports activities drinks and fruit juices can scale back bloating whereas offering carbs, they’re simpler in your digestive system than strong meals alone.
The Practice-Low Debate: Does It Really Work?
However what if I informed you some coaches are actually recommending you do the other throughout coaching, strategically limiting carbs to enhance efficiency?
The “prepare low, compete excessive” technique entails limiting carbohydrates throughout particular coaching classes to reinforce fats metabolism and metabolic variations, whereas sustaining excessive carbohydrate availability for competitions.
Common protocols embody twice-a-day coaching with low glycogen for the second session, or fasted morning runs.
Sadly, the analysis right here is extra sophisticated than social media influencers would have you ever imagine.
Whereas a foundational 1983 examine [11] discovered carbohydrate restriction resulted in adaptation that conserved carbohydrate shops, subsequent analysis has produced blended outcomes, some research present advantages whereas others point out these advantages don’t translate into long-term improved endurance efficiency, particularly on the elite degree.
The issues are actual: a scientific assessment [12] discovered that coaching depth is usually compromised with depleted glycogen, and there are potential penalties together with decreased efficiency capability and decreased carbohydrate oxidation functionality.
For many leisure runners with restricted coaching time, the analysis suggests train-low methods have a slender software, if any.
Your Tuesday evening monitor exercise is tough sufficient with out including pointless metabolic stress.
Frequent Errors That Sabotage Your Loading
The most important mistake? Analysis persistently demonstrates [13] that one massive pasta dinner the evening earlier than gained’t adequately replenish your muscle glycogen shops, you want 2-3 days of elevated consumption.
Some of the widespread causes carb loading doesn’t work is that athletes merely don’t eat sufficient carbohydrates.
Sure, it’s genuinely tough to eat 560-840g of carbs per day.
However that’s what the analysis reveals is critical for full supercompensation.
Different pitfalls: making an attempt new meals throughout loading week (keep on with what you recognize), ignoring hydration (you want water to retailer that glycogen), and persevering with high-volume coaching (which prevents the supercompensation impact).
The Backside Line
The evolution of carb loading analysis provides us a transparent message: you don’t want excessive depletion phases, week-long protocols, or sophisticated train-low methods.
For many leisure runners, the fashionable method is elegantly easy, 2-3 days of elevated carbohydrate consumption mixed with decreased coaching will maximize your glycogen shops.
Match your technique to your race distance.
Skip carb loading for 5Ks and 10Ks.
Use a modified method for half marathons.
Go all-in for marathons.
And all the time follow your protocol throughout coaching earlier than utilizing it on race day.
Once you nail this piece of preparation, you’ll expertise what it feels prefer to surge by way of mile 20 as an alternative of hitting the wall.
That’s the distinction correct fueling makes.
