At official races, you might see sponsors handing out non-alcoholic beer to participants, and some athletes even enjoy a cold one after a run. There’s a common belief among runners that beer can work as an isotonic or sports drink since it has carbs and electrolytes. These electrolytes—like sodium, potassium, and magnesium—are essential for keeping our muscles and nerves functioning well.
But is beer actually isotonic?
An isotonic drink has a similar concentration of dissolved substances as human blood plasma, which includes things like glucose and those electrolytes. If a drink has more water than dissolved stuff, it’s called hypotonic, and if it’s more concentrated, it’s hypertonic.
These differences matter because they affect how quickly your body absorbs the drink. Hypotonic drinks get absorbed fast, boosting your blood volume and hydrating you quickly. Isotonic and hypertonic drinks take a bit longer to absorb but help replenish those important electrolytes and carbs.
Experts have tested various beers and found that most alcoholic ones are hypertonic, while non-alcoholic beers are hypotonic. So, if you’re trying to stay hydrated, alcoholic beer isn’t the best choice. Plus, drinks with over 4% alcohol can mess with your body’s ability to retain fluids and can even make dehydration worse by dilating blood vessels.
When people talk about isotonics, they often just think of any sports drink that’s a non-carbonated, flavored liquid with added sugar and electrolytes. Beer does have water, carbs, and electrolytes, so some fans think it’s a good post-workout option.
But can beer really replace a sports drink?
During long, intense workouts, your body burns through carbs, which are crucial for fueling your muscles and brain. To keep up your pace, you’ll need to refuel after about an hour of hard work.
When you sweat, you lose a lot of salt, and scientists used to think that could lead to a condition called hyponatremia, where sodium levels drop too low. This can cause headaches, nausea, swelling, anxiety, fatigue, confusion, and even wheezing. While experts are skeptical that just drinking electrolyte water can prevent this, they still recommend having 0.5-1 liter of water with 6-8% carbs and a good amount of sodium and potassium every hour during intense exercise.
Sports drinks usually have around 6g of carbs per 100g, about 40mg of sodium, and 15-18mg of potassium. Even electrolyte tablets can pack more of a punch, with around 60mg of sodium and 100-450mg of potassium per 100g of drink.
In comparison, beer only has about 4mg of sodium and 3.5g of carbs per 100g, which is way less than what you’d find in a proper sports drink. Sure, beer lovers might argue that they eat salty snacks with their beer, which adds some sodium and carbs, but let’s not forget that beer also has alcohol, which can be a health risk.
So, what’s the takeaway?
- Beer isn’t an isotonic drink.
- It doesn’t have enough electrolytes or carbs to replace a sports drink.
- It could actually hinder an athlete’s recovery and fitness, even if there’s not a ton of research on that.
- Plus, alcoholic beer can be addictive and harmful in the long run.
So, maybe stick to the sports drinks after a workout!
