When you’re several hours into a long ride or race and hitting that dreaded wall, you might notice experienced cyclists reaching for something unexpected.
That familiar red can of Coca-Cola isn’t there by chance. It’s become one of the most trusted tools in endurance cycling, from Sunday club runs all the way up to the final hour of a Tour de France stage.
But here’s the twist. The reason it works isn’t the one most riders assume. It’s not simply that “sugar and caffeine give you a boost.” What’s actually going on inside your gut and your tired legs is more interesting than that, and understanding it is the difference between using Coke as a secret weapon and wasting it.
Why Coca-Cola Works for Cyclists
When you’re deep into a long ride, your body starts demanding quick energy. Coca-Cola offers a combination of fast-acting carbohydrate and a little caffeine that lands at exactly the moment depleted muscles are crying out for it.
Each can contains around 39 grams of sugar, delivering an almost immediate lift when traditional fueling starts to fall short.
That’s the short version most people know. But why those 39 grams work so well late in a ride, and why the same can does far less for you at the start, comes down to some genuinely clever physiology. Here’s what’s really going on.
What’s Actually Happening Inside Your Body
Once you’ve been riding hard for more than about 90 minutes, the carbohydrate stored in your muscles (your glycogen) starts running low. Your fast-twitch fibers, the ones you lean on for climbs, sprints, and attacks, empty first. That’s exactly why the hard efforts late in a ride feel so brutal: the fuel for them is gone.
At that point, your body becomes increasingly dependent on carbohydrate you eat while you ride to keep your blood sugar up and your power on. When there’s nothing left in the tank and nothing coming in, you get the full-blown bonk: low blood glucose, heavy legs, and the wall every cyclist dreads.
This is where Coke earns its reputation. Its sugar is high-glycemic, which means it’s absorbed fast and delivered straight to working muscle. The clever part is the type of sugar. Coke is sweetened with sucrose or high-fructose corn syrup, both of which are roughly half glucose and half fructose.
Why does that matter? Your gut absorbs glucose and fructose through two separate doorways. Glucose on its own maxes out at about 1 gram per minute, and then the doorway jams. Add fructose and you open a second doorway, which pushes total carbohydrate absorption up to around 1.75 grams per minute. That’s roughly 65% more fuel per minute reaching your legs. Studies show this glucose-and-fructose combination can improve endurance performance by around 8 to 9% over glucose alone, and it’s easier on your stomach too.
🥤 So Coke isn’t magic, and it’s worth being honest about that. It’s just a well-timed dose of exactly the kind of dual-sugar fuel your gut is built to absorb quickly when you’re running on empty. It does the same job as a glucose-fructose sports drink, only in a form that tastes incredible after five hours in the saddle.
The Science: Study on Coca Cola and Cycling
A study, titled “Effect of different protocols of caffeine intake on metabolism and endurance performance,” examined how various caffeine intakes, including Coca-Cola (Coke), affected endurance athletes.
• In Study A, 12 subjects were given 2 x 5 ml/kg Coca-Cola during the latter stages of 2-hour steady-state (SS) cycling and a time trial (TT). This resulted in a 3.1% improvement in TT performance.
• In Study B, eight subjects consumed a caffeinated, 11% carbohydrate (CHO) cola (also referred to as “Coke”) during the final 40 minutes of SS and the TT. This enhanced TT performance by 3.3%.
💡 Overall, the research concluded that replacing a sports drink with Coca-Cola in the latter stages of exercise was equally effective for boosting endurance, primarily due to its low caffeine intake (approximately 1.5 mg/kg).
How the Pros Actually Use It
Watch the closing kilometers of a Grand Tour stage and you’ll spot it: soigneurs handing flat Coke up to riders, or a can cracked open the moment they roll across the line. It’s one of the worst-kept secrets in professional cycling.
There are a few reasons the pros save it for late:
- The timing is physiological. As we covered, glycogen is most depleted in the final hour, which is exactly when a fast-absorbing sugar hit does the most good.
- It beats flavor fatigue. After five or six hours of gels, bars, and sweet sports drinks, riders build up a real aversion to the taste. One sports dietitian described a can of Coke late in a race as giving riders “a new sense of life.” It refreshes the palate and gets them taking on carbs again when they’d otherwise stop eating.
- It kickstarts recovery. Teams also hand riders Coke straight after a stage, when appetite is crushed after 200km but the body needs carbohydrate fast to start refilling glycogen stores.
It’s worth a reality check, though. You’ll sometimes hear that “nearly 90% of Tour riders use Coke.” That’s a popular claim, but it comes from social media rather than any formal survey, so treat it as color rather than hard fact. What’s true is that the practice is genuine, widespread, and grounded in sound physiology.
Comparing with Traditional Sports Drinks
Standard Sports Drinks
Most cycling-specific drinks provide a balanced mix of electrolytes and moderate sugar levels. They’re engineered for sustained energy release throughout your ride.
The Coca-Cola Advantage
Unlike sports drinks, Coke delivers a more concentrated sugar hit and higher caffeine content. This combination creates a powerful mid-ride boost when you’re hitting that dreaded wall.
Flat vs. Fizzy, and How to Mix Your Own Race Bottle
Here’s a mistake beginners make. They grab a cold, fizzy can and glug it down mid-effort. The pros never do that, and there’s a good reason.
Why the pros go flat. The carbonation in Coke is carbon dioxide gas. Drink it while you’re working hard and that gas expands in a stomach that’s already struggling to empty, which leaves you bloated, belching, and queasy. Coke is acidic too, which makes it worse. Letting it go flat removes the gas while keeping all the sugar and caffeine you actually want. Teams often open cans well in advance, or mix the drink the night before, so the fizz is long gone by race time.
Why you should dilute it. Undiluted Coke is a very concentrated sugar solution, so it empties from your stomach slowly. Sports drinks aim for a gut-friendly 6 to 8% carbohydrate concentration, and you can bring Coke into that same range with water.
A simple race-bottle recipe:
- 200ml flat Coke plus 200ml water gives you about 400ml at roughly 5.5% carbohydrate, right in the range your gut can handle.
- Add a small pinch of salt. Coke has virtually no sodium, and on a long, hot ride you’re losing plenty in sweat. A pinch turns it into something much closer to a proper sports drink.
- Keep it cool, not ice-cold. Slightly cool is easier to drink and helps you keep your body temperature down. Freezing-cold plus any leftover fizz is a recipe for stomach trouble.
Mix it the day before so the carbonation dissipates overnight, keep it in a spare bidon, and reach for it in the final third of your ride. One tip: everyone’s gut is different, so try it on a training ride first rather than debuting it on the day of your big event.
When and How to Use It
Optimal Timing
Save your Coke for the second half of long rides. Using it too early could trigger an unwanted sugar crash and stomach discomfort.
Correct Portions
A small amount (150-200ml) usually does the trick. The concentrated nature means you don’t need to drink large quantities.
Alternative Options
Several alternatives exist, though they might not pack the same punch:
- Natural cola variants
- Caffeinated sports drinks
- Energy gels
- Maple or coconut water
Common Mistakes to Avoid
Even riders who swear by Coke often get it wrong. Watch out for these:
- Reaching for it too early. Coke can rescue you from an approaching bonk, but it can’t undo hours of under-fueling. If you skip your regular carbs early and try to survive on cola, you’ll probably just upset your stomach. Fuel steadily from the start (aim for 30 to 60 grams of carbohydrate an hour), and treat Coke as a late-ride finisher.
- Overdoing it. More isn’t better. A concentrated, acidic drink in large volumes is a fast track to stomach trouble. A modest dose does the job.
- Fearing a “sugar crash” more than you should. This one’s largely a myth for cyclists. The rebound low-blood-sugar effect people worry about is mostly a resting phenomenon. While you’re riding hard, your muscles are pulling glucose out of your blood so fast that a classic crash is unlikely. The real risk isn’t the sugar itself. It’s a big, isolated hit with nothing else coming in. Keep fueling around it and you’ll be fine.
- Making it a habit. Coke is sugary and acidic, so daily use isn’t kind to your teeth or your waistline. On race day it’s a smart tool. As an everyday drink it isn’t. Drink it fairly quickly rather than sipping it over an hour, and rinse with water afterward to protect your enamel.
Important Considerations
While effective, Coca-Cola shouldn’t replace proper sports nutrition. Consider it a tactical weapon in your fueling arsenal, not your primary energy source.
The carbonation can actually help settle mid-ride stomach issues. However, some riders might find the fizz uncomfortable during intense efforts.
Frequently Asked Questions
Does Coca-Cola really help cycling performance?
Yes, when you use it late in a long ride. Its fast-absorbing glucose-fructose sugar tops up depleted energy stores quickly, and a small amount of caffeine gives a modest lift. It’s not magic. It works the same way a glucose-fructose sports drink does. But the timing and the taste make it genuinely effective.
When should I drink Coke on a ride?
In the second half, ideally the final third, of rides lasting more than about two hours. That’s when your glycogen is most depleted and a fast sugar hit does the most good. Early on it offers little benefit and can upset your stomach.
Should Coke be flat or fizzy?
Flat. The carbonation causes bloating and nausea during hard efforts. Open the can in advance or mix your drink the night before so the fizz disappears.
How much Coke should I drink?
A small dose of around 150 to 200ml is plenty. Diluting it with an equal part water, plus a pinch of salt, makes it easier on your gut and closer to a proper sports drink.
Will Coke give me a sugar crash?
It’s much less likely than people think while you’re actually riding, because your working muscles are burning through blood glucose fast. The bigger risk is drinking a large amount on its own with no other fueling, so keep taking on carbs around it.
Is Coke better than a sports drink?
It’s not better, just different. A sports drink gives you steady energy plus electrolytes across the whole ride. Coke works best as a late-race pick-me-up. Many riders use both: sports drink early, Coke to finish.
Read more:
- Canadian cyclist saves $300 per month with homemade gels
- Chocolate milk better for cyclists than expensive sports drinks?
Final Thoughts
Having a small can of Coke in your jersey pocket can provide that extra edge when energy levels start dropping.
Just remember to use it strategically and don’t overdo it.
I’d be interested if a ore diabetic can use this strategy without negative implications
“A small can of Coke in your jersey pocket” will be both warm and so pressurized it will blow up your nose when you pop the top. About the only time I drink Coke anymore is on a ride and then it has to be cold, cold, cold! It’s amazingly good under those conditions.
But, for your body in general, not necessarily good for it, why not just a zip bag full of sugar cubes!
I drink a Coke about once a year then wonder how I used to like it, Now I find Coke gross, and warm and shaken one would be even worse. There’s better ways to get a caffeine and glucose hit.
Learned this 50 years ago. Open and refrigerate a can of Coke the night before a long ride or race. Add and dilute to the last bottle used. Drink during the last 10 miles.