Soda may be filled with enough caffeine and sugar to give you a rush of energy before exercising, but the effects of carbonated drinks on exercising outweigh the benefits. Soda or other sugary, carbonated drinks can affect your body during exercise and afterward.
While consuming carbonated water may not be that much different from drinking regular water, sugary soda can have a negative effect on your entire body — whether or not you’re exercising. Drinking sugary sodas or energy drinks may affect your athletic performance, impair your metabolism, hurt your kidneys and contribute to weight gain.
Carbonated Drinks Versus Sodas
Before delving into the effects of carbonated drinks on exercising, it's important to first differentiate between sodas, soft drinks and carbonated drinks. When a drink is carbonated, it contains dissolved carbon dioxide, which gives it its bubbles or fizzy composure.
While many common sodas are carbonated, water is often carbonated as well — like sparkling waters or seltzers. Seltzers typically have no added sugars or syrups and aren't much different from drinking regular water.
A March 2016 study published in the American Journal of Clinical Nutrition found that sparkling water hydrated people just as well as still water. Since there are no sugars or calories in sparkling water, it also doesn't contribute to weight gain or other negative health effects the way other beverages might. Besides potentially making you feel a bit more bloated because of the gas, seltzers are likely just as harmless as regular water when you're exercising.
Soft drinks and sodas, meanwhile, encompass the beverages that contain carbonation in combination with added sugars, and real or artificial flavoring or syrups. Some soft drinks contain a slew of other additions as well, such as caffeine or preservatives.
Typically, soft drinks will be high in sugar and calories and may feel more filling than drinking regular water. Unlike drinking regular water or sparkling water, there may be more negative effects of sugary, carbonated drinks on exercising.
Soda, Sugar and Athletic Performance
Because of the caffeine or sugar content of sodas and soft drinks, gulping down a bottle of soda before a workout can lead to a surge of energy at first. Some athletes reach for a cup of coffee or a Coca Cola pre-workout, hoping to get a quick fix for energy.
Other athletes drink sports drinks or soft drinks post-workouts, in the hopes of replenishing depleted electrolytes and glycogen stores. In fact, some research has examined how highly competitive or intensive athletes perform when drinking fructose before or after a several-hour workout, as this may help to restore their liver's glycogen stores.
An August 2017 study published in the European Journal of Sports Science found that drinking fructose could have an effect on an athlete's fatigue and metabolism, possibly providing them with a longer store of energy than someone just drinking water. This is why a competitive cyclist may drink a sugary beverage during a marathon.
It's fairly accepted, however, that while drinking a lot of sugar may be helpful for a small fraction of intense endurance athletes — like cyclists or runners doing hours of marathons — the same benefits don't carry over for the average person doing a half hour or hour workout. In fact, drinks high in fructose would actually be harmful during exercise for the average person.
While certain sports drinks are designed to provide you with sodium, electrolytes and some sugar after a workout, most common soft drinks — like Pepsi, Coca Cola or lemonades — simply contain high levels of sugar without the electrolytes. Many sodas even have high-fructose corn syrup, which along with other types of added sugars has been linked to weight gain, increased triglycerides and tooth decay, according to the Mayo Clinic.
According to Harvard Health, 42 percent of added sugar comes from soda and energy or sports drinks. That's far more than the added sugar gleaned from desserts, candy, syrup or cereals.
According to an April 2014 study published in JAMA Internal Medicine, the more adults consumed added sugar, the higher their risk for cardiovascular disease and mortality. Over the long-term, soda consumption can also increase the risk for type 2 diabetes, obesity and other chronic diseases. It can even have an effect on your brain.
Drinking soda after working out, therefore, may not be the best choice. To avoid grabbing an energy or sports drink that's packed with too much sugar, make sure to read the food labels before buying it. You'll be able to track how many added sugars are inside the beverage — anything from corn sweetener, corn syrup and high-fructose corn syrup to malt sugar and molasses.
Read more: Vegetables That Lower Blood Sugar Levels
Soda May Hurt Your Kidneys
The effects of carbonated drinks on exercising may even extend to your kidneys. A small February 2019 study published in the American Journal of Physiology examined how certain soft drinks, defined to be high-fructose and caffeinated, affected people during and after exercise in the heat.
In the study, researchers measured healthy adults working out on treadmills and lifting for 45 minutes. After the workout, the participants were given either 16 ounces of a high-fructose, caffeinated soft drink or water to drink, then sent to exercise more. This cycle was repeated for about four hours, then participants were given their assigned beverage to drink when they left.
The researchers tracked the participants' core body temperature, heart rate, blood pressure and biomarkers of kidney injury before and after the trial. They found that the people assigned to soft drinks had higher levels of certain kidney injury markers, such as creatinine in their blood and a lower glomerular filtration rate.
The same people also had higher levels of vasopressin, a hormone that raises blood pressure, and were deemed mildly dehydrated. Participants who drank water didn't experience any of these negative effects, leading the researchers to conclude that soft drinks didn't work to hydrate people in the heat and had a harmful effect on the kidneys.
Exercise Can Turn Things Around
The good thing is, if you're a chronic soda drinker, starting an exercise routine may actually help protect you against some of the beverage's worst health outcomes. And quitting soda altogether can completely turn your health around for the better.
In a small March 2016 study published in PLOS One, researchers tracked rats given cola soft drinks as they exercised aerobically, and compared them to rats drinking cola who were sedentary. Chronic soda consumption was linked to higher levels of triglycerides, as well as an increased heart rate, oxidative stress and inflammation.
The researchers of that study did find, however, that regular exercise helped protect against some of these problems. Another December 2017 study published in the Journal of Affective Disorders also found that people with compulsive sugar eating could benefit from moderate physical exercise as well.
That being said, if you hope to avoid the negative health effects of carbonated soft drinks on exercising, you probably shouldn't be reaching for a Coca Cola pre-workout or a sugar-packed energy drink afterwards, even after an intense workout. Instead, opt for regular water, unsweetened teas or sparkling water. These unsweetened options will not only lower your sugar intake and be better for your metabolism post-workout, but they'll also keep you far more hydrated.
- American Journal of Clinical Nutrition: "A Randomized Trial to Assess the Potential of Different Beverages to Affect Hydration Status: Development of a Beverage Hydration Index"
- European Journal of Sports Science: "Glucose-Fructose Ingestion and Exercise Performance: The Gastrointestinal Tract and Beyond"
- Mayo Clinic: "Nutrition and Healthy Eating"
- Harvard Health: "The Sweet Danger of Sugar"
- JAMA Internal Medicine: "Added Sugar Intake and Cardiovascular Diseases Mortality Among US Adults"
- American Journal of Physiology: "Soft Drink Consumption During and Following Exercise in the Heat Elevates Biomarkers of Acute Kidney Injury"
- PLOS One: "Beneficial Effect of Moderate Exercise in Kidney of Rat after Chronic Consumption of Cola Drinks"
- Journal of Affective Disorders: "Sugars, Exercise and Health"