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How Drinking Coffee Before A Workout Affects Your Performance

Abby Moore
May 7, 2020
Abby Moore
mbg Nutrition & Health Writer
By Abby Moore
mbg Nutrition & Health Writer
Abby Moore is an editorial operations manager at mindbodygreen. She earned a B.A. in Journalism from The University of Texas at Austin and has previously written for Tribeza magazine.
May 7, 2020

Before you start working out, you want to consider how to properly fuel your body. Whether it's food, water, or other beverages, what you consume can affect your endurance and athletic performance. Though coffee may provide energy throughout your workday, how does it affect a workout? 

We consulted experts in fitness and nutrition to figure out whether coffee helps or hurts a workout, when to drink it, and how much you should consume. 

Is it a good idea to drink coffee before a workout? 

Drinking coffee before a workout can help with both mental and physical energy levels, exercise science and nutrition expert Shawn Talbott, M.S., Ph.D., says. In fact, he sometimes drinks his iced coffee during a workout.  

"The high content of polyphenols in coffee can help with antioxidant and anti-inflammatory protection, as well as blood sugar balance," he says. Each of these aspects is important for exercise performance and especially for post-exercise recovery and tissue repair.

Along with the polyphenols, the caffeine in coffee has performance-enhancing properties. In an overarching review of caffeine and exercise, researchers analyzed 4,800 people across 300 studies and found that exercise performance increased up to 16% after participants drank caffeine1.

The stimulatory effects of caffeine have also been shown to help the body burn fat2. So if weight loss is one of your exercise goals, drinking coffee beforehand may help. 

How long before a workout should I drink coffee?

"Caffeine takes about 30 minutes to start working to boost energy levels," Talbott explains, "so depending on the duration of your workout, you can 'time' when you want the caffeine effect to exert itself." 

For short exercises, drink your coffee before you leave the house. By the time you get to the gym and start exercising, the caffeine should take effect. 

For endurance exercises, save your coffee for the last hour. "As an ultra runner and Ironman triathlete," Talbott says, "I save my iced coffee for the later portion of my long workouts." The last stretch of an endurance run or bike ride is when you'll probably need a boost. 

Just keep in mind how coffee tends to affect you. If a morning cup of coffee generally makes you poop, it might not be conducive to cardio. Drinking iced coffee or cold brew instead of hot coffee may help, though, as the warm liquid may increase intestinal motility3 and increase the urge to go. 

Since your tolerance level may differ from other people's, experiment with drinking your coffee anywhere from 15 to 45 minutes before exercise. 

How much coffee should I drink?

A standard cup of coffee contains about 100 mg of caffeine, Talbott says. However, depending on how strong the coffee is, that number may double. 

"That 100 mg of caffeine and associated polyphenols will boost mental and physical performance starting at about 30 minutes and lasting for about two to four hours," Talbott explains, though the exact time depends on your personal ability to metabolize caffeine, which differs between people.

One study found that participants who drank 4.5 milligrams of caffeine per kilo of their body weight4 saw a 15% improvement in athletic performance. For example, a 140-pound person would need to drink 285 milligrams, which is about one 20-ounce cup of coffee.

And even if you're a heavy coffee drinker, research says that doesn't change the positive effects caffeine5 has on athletics.

Are there any potential side effects or downsides? 

While some believe that coffee can lead to dehydration during a workout, Talbott says as long as you're properly drinking water, you should be fine.

Drinking too much coffee (about 400 mg or four cups a day) may lead to potential downsides, like over-caffeination. "After 400 mg of caffeine, you start to see the beneficial effects of coffee get replaced with negative side effects," Talbott says. These effects may include high tension or anxiety, heart palpitations, an upset stomach from increased acid production, and increases in cortisol. 

If you're doing an evening workout, he advises you to stop drinking coffee at least four hours before bed to avoid sleep disturbances.  

Bottom line.  

Coffee may be able to help improve your athletic performance. If you choose to drink coffee as a fitness enhancement, try not to exceed the recommended daily intake (less than four cups), and be sure to properly hydrate with water throughout.

Abby Moore author page.
Abby Moore
mbg Nutrition & Health Writer

Abby Moore is an editorial operations manager at mindbodygreen. She earned a B.A. in Journalism from The University of Texas at Austin and has previously written for Tribeza magazine. She has covered topics ranging from regenerative agriculture to celebrity entrepreneurship. Moore worked on the copywriting and marketing team at Siete Family Foods before moving to New York.