Caffeine and Exercise

Reviewed by Sarah Klemm, RD, CD
Caffeine and Exercise

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Caffeine is perhaps the most socially acceptable and frequently used drug. Yes, caffeine is a drug. More specifically, it's an ergogenic aid, meaning caffeine may help the body perform better during physical activity. The ergogenic effect of caffeine occurs because it changes a person's perception of how much effort an individual puts forth while exercising. In other words, caffeine gives exercisers a boost in energy so they push themselves harder.

What is Caffeine?

Caffeine occurs naturally in some seeds and plants, the most common being coffee and cacao beans. Historically, coffee and tea have been among the most common ways that people have consumed caffeine, but manufacturers have started producing it chemically and adding it to numerous drinks and foods for its physical and psychological boost. Most people are familiar with energy drinks, which may help to reduce fatigue and improve physical performance. Many individuals now also consume caffeine pre-workout, predominantly through energy drinks or gels, to reap the benefits of a more exerting workout.

How Does it Work?

Caffeine acts as a stimulant on the nervous system (including the muscles, heart and other organs) by binding to certain receptors and blocking a chemical the body produces more of during stress and trauma.

Research seems to consistently support the positive role of caffeine on physical performance, however it doesn't appear to affect everyone the same. Those participating in endurance activities, such as running or playing sports, may see more benefit than those doing resistance activities, such as weight lifting. Individuals who aren't used to consuming caffeine on a regular basis also may see more benefits than those who do.

How Much Caffeine is Healthy?

According to the 2015-2020 Dietary Guidelines for Americans, adults who choose to include caffeinated beverages in the form of coffee should not consume more than 400 milligrams of caffeine per day. A shot of espresso has about 75 milligrams of caffeine, whereas energy drinks can range from 47 to 163 milligrams of caffeine per eight fluid ounces.

It is not recommended that people start consuming caffeinated beverages if they are not currently doing so. Used properly and within the recommended amounts, caffeine may have positive outcomes. However, it also is important to make wise choices, as many caffeinated beverage also are sources of calories from added sugars.

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