It all started with a single tweet. Our MH colleague Brady Holmer posted on X about Coke Zero as “performance fuel”, and suddenly the internet had opinions. Some people swore by it, others mocked the idea, and a few others just wanted to know: Is Coke Zero actually good for athletes?
Coke Zero has 70 mg of sodium and 90 mg of potassium.
— Brady Holmer (@B_Holmer) January 29, 2025
Basically an electrolyte supplement with caffeine.
Performance fuel. pic.twitter.com/RafgnrEG3i
Regular Coke has long been a staple in ultrarunning and cycling—after all, caffeine and sugar are an unbeatable combo when you’re deep in the pain cave.
But what about Coke Zero?
Can a sugar-free, zero-calorie soda actually hold any value for endurance athletes, or is it just a fizzy placebo?
Let’s break down the science and see if this viral take holds any weight—or if it’s just the internet running on caffeine and clout.
Coke Zero vs. Traditional Sports Drinks
First, let’s break down what’s inside that red can of “performance fuel”:
Coke Zero (12 oz / 355 ml)
- Calories: 0
- Sodium: 40 mg
- Potassium: 60 mg
- Carbohydrates: 0 g
- Sugar: 0 g
- Caffeine: 34 mg
For Comparison: Popular Sports Drinks
| Drink | Calories | Sodium (mg) | Potassium (mg) | Carbs (g) | Sugar (g) | Caffeine (mg) |
|---|---|---|---|---|---|---|
| Gatorade Thirst Quencher (12 oz) | 80 | 160 | 45 | 21 | 21 | 0 |
| Powerade (12 oz) | 80 | 150 | 35 | 21 | 21 | 0 |
| Liquid IV (1 stick in 16 oz) | 45 | 500 | 380 | 11 | 11 | 0 |
| Regular Coca-Cola (12 oz) | 140 | 45 | 0 | 39 | 39 | 34 |
Electrolytes: Is Coke Zero Hydrating?
Sodium and potassium are crucial for endurance athletes—they help maintain fluid balance, muscle contractions, and prevent cramping.
Coke Zero does technically contain some electrolytes (40 mg of sodium and 60 mg of potassium per 355 ml), but let’s be real—it’s nowhere near what you’d get from a dedicated sports drink.
For comparison, Gatorade has four times the sodium of Coke Zero. Liquid IV? It’s packing 500 mg of sodium per serving, meaning if you’re sweating buckets, Coke Zero won’t be the thing saving you from bonking.
In short: Coke Zero isn’t going to replace your electrolyte drink anytime soon. But if you’re drinking it alongside actual hydration strategies, it’s not completely useless either.
What About Caffeine?
Caffeine is where Coke Zero gets interesting. It’s been proven time and time again that caffeine can improve endurance performance by reducing perceived exertion and increasing fat oxidation. That’s why so many energy gels, hydration mixes, and race-day drinks come with a caffeine option.
Coke Zero contains 34 mg of caffeine per can, which is about half of what’s in an 8 oz coffee (80 mg). Regular Coke has the same amount of caffeine, so in that sense, Coke Zero can still give you a little mental and physical boost.
But here’s the thing: Unlike regular Coke, Coke Zero lacks sugar—which is actually a big deal in endurance sports.
In ultra races, the 39 grams per serving of sugar in regular Coke provides a quick glycogen replenishment, giving athletes a fast energy boost.
Without sugar, Coke Zero’s caffeine is just a mild pick-me-up without the actual fuel. It might keep you mentally sharp, but it won’t help your muscles keep going like the classic Coca-Cola sugar bomb does.
Is Coke Zero Used in Endurance Sports?
While regular Coke is a tried-and-true fuel source in endurance events (Tour de France riders have been guzzling it for decades, and if you’ve ever run an ultra, it’s always on the aid station table), Coke Zero is more of a niche preference.
Some athletes prefer it as a non-caloric, caffeine source, especially if they’re in a fat-adapted state or don’t want to spike their blood sugar mid-race. Others use it post-race, when they’re craving carbonation but don’t want extra sugar.
One study even suggested artificial sweeteners in Coke Zero may trigger an insulin response despite having no sugar, meaning it might still have metabolic effects—though this is still debated.
The Verdict: Should You Drink Coke Zero for Endurance?
✅ Yes, if…
- You want a low-calorie caffeine boost without sugar.
- You like carbonation and the taste of Coke.
- You’re looking for a psychological pick-me-up rather than a fuel source.
🚫 No, if…
- You need actual energy (sugar) to fuel your muscles.
- You’re trying to replace electrolytes lost in sweat.
- You expect it to perform the same as regular Coke mid-race.
At the end of the day, Coke Zero isn’t a “sports drink,” but it’s also not useless. If you’re an athlete who loves it, keep drinking it—but don’t expect it to replace your hydration and fueling strategies.
For those late-race “zombie mode” moments? You’re probably better off reaching for the real thing.
