You’re standing at mile 20 of your objective marathon, legs feeling surprisingly recent, when all of a sudden it hits—that acquainted fog, the heavy legs, the entire lack of energy.
You’ve hit the wall. Onerous.
In the meantime, the runner subsequent to you, who you’ve been pacing for the final hour, surges forward like they only began the race.
That’s not stunning if you happen to’ve been operating for any variety of years.
However right here’s what may shock you: the carb loading recommendation you adopted may be many years old-fashioned, and really working in opposition to you.
The analysis on carbohydrate loading has advanced dramatically over the previous 20 years. What labored for marathoners within the Nineteen Sixties isn’t essentially what fashionable science tells us will optimize your efficiency at this time.
The Basic Protocol: The place Carb Loading Began (and Why We’ve Moved On)
Let’s take a look at the place this complete carb loading factor got here from.
Again within the Nineteen Sixties, Swedish researchers found you can double your muscle glycogen shops with a strategic food regimen manipulation [1].
Think about storing twice as a lot gas in your muscle groups earlier than a race.
The catch? The unique protocol was brutal.
Days 1-3: Beat your self up with exhausting 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 all of a sudden everybody wished in on the key.
However right here’s what they didn’t promote: the negative effects had been terrible.
The high-fat, low-carb section left runners with severe digestive points.
That tough exercise every week earlier than race day? It compromised restoration whenever 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 can obtain almost the identical glycogen ranges with out the depletion section.
Even higher: well-trained athletes may max out their shops in simply 1-2 days as an alternative of a full week.
What’s Really Occurring in Your Muscle tissues
Right here’s what’s really taking place whenever 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: whenever you deplete your glycogen shops by way of train, your muscle cells principally panic and improve their gas 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 skilled 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 couple of days on high-carbohydrate diets, that’s a 30-40% enhance in gas storage.
Every gram of glycogen is saved with 3 grams of water, which explains the 1-2kg weight achieve you may discover.
The Fashionable Strategy: Less complicated and Science-Based mostly
The problem is that we now know you may obtain the identical glycogen supercompensation with out all of the struggling.
Fashionable analysis exhibits [5] there’s no must deplete glycogen shops earlier than loading, and carb loading for simply 24-36 hours is enough, particularly for skilled athletes.
For many leisure marathoners, the candy spot is 2-3 days pre-race.
For extremely skilled athletes, 1-2 days might suffice.
Information from a number of research [6] exhibits the goal is 8-12 grams of carbohydrate per kilogram of physique weight every day through the loading section.
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 suggestion, 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 revealed within the Journal of Utilized Physiology [7] exhibits you need to deal with quick carbohydrates, refined sugars, white rice, and starches that digest simply.
White bread, pasta, potatoes, and rice ought to be your go-to meals.
Save the brown rice and complete grain bread for after the race.
Right here’s what’s totally different from the basic protocol: NO depletion section, 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 fallacious: they apply marathon carb loading methods to each race distance.
Let’s be clear about this.
For 5Ks and 10Ks: Skip the carb loading completely.
Your regular glycogen shops can gas 90 minutes of operating, which implies most runners by no means faucet out throughout these shorter races.
Simply eat usually, keep hydrated, and have a good race-morning breakfast.
For half marathons: It relies on your end time.
In case you’re crossing the road in beneath 90 minutes, you in all probability don’t must carb load.
Working 1:45 or slower? Take into account a modified 2-3 day protocol with elevated carbs within the remaining 24 hours.
For marathons: That is the place carb loading turns into non-negotiable.
The analysis exhibits a 2-3% efficiency enhance [8], and one research 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 received 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 operating brief and light-weight.
Improve the carb proportion at every meal whereas reducing fats and protein.
Analysis exhibits [9] you need to make your largest meal lunch the day earlier than, not dinner, which permits correct digestion and glycogen storage somewhat than leaving you with a full abdomen on race morning.
For race morning timing: a research 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.
High off with a gel 10 minutes earlier than the beginning.
What about liquid energy? Subject-based analysis [10] suggests sports activities drinks and fruit juices can cut back bloating whereas offering carbs, they’re simpler in your digestive system than stable meals alone.
The Practice-Low Debate: Does It Really Work?
However what if I instructed you some coaches are actually recommending you do the other throughout coaching, strategically proscribing carbs to enhance efficiency?
The “practice low, compete excessive” technique entails proscribing carbohydrates throughout particular coaching periods to boost fats metabolism and metabolic diversifications, whereas sustaining excessive carbohydrate availability for competitions.
Fashionable protocols embrace twice-a-day coaching with low glycogen for the second session, or fasted morning runs.
Sadly, the analysis right here is extra difficult than social media influencers would have you ever imagine.
Whereas a foundational 1983 research [11] discovered carbohydrate restriction resulted in adaptation that conserved carbohydrate shops, subsequent analysis has produced combined 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 overview [12] discovered that coaching depth is commonly 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 utility, if any.
Your Tuesday night time observe exercise is difficult sufficient with out including pointless metabolic stress.
Widespread Errors That Sabotage Your Loading
The most important mistake? Analysis persistently demonstrates [13] that one large pasta dinner the night time earlier than gained’t adequately replenish your muscle glycogen shops, you want 2-3 days of elevated consumption.
Probably the most frequent causes carb loading doesn’t work is that athletes merely don’t devour sufficient carbohydrates.
Sure, it’s genuinely tough to eat 560-840g of carbs per day.
However that’s what the analysis exhibits is critical for full supercompensation.
Different pitfalls: attempting new meals throughout loading week (keep on with what you already know), 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 offers us a transparent message: you don’t want excessive depletion phases, week-long protocols, or difficult 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 at all times observe your protocol throughout coaching earlier than utilizing it on race day.
Whenever you nail this piece of preparation, you’ll expertise what it feels wish to surge by way of mile 20 as an alternative of hitting the wall.
That’s the distinction correct fueling makes.
