Should You Have Coffee Before a Workout?

Many people start the day with a cup of coffee. The caffeine kick makes them more alert and ready to face the day.

But coffee isn’t just for breakfast. Research suggests that having coffee –– or another caffeine source –– before a workout could boost your performance.

Is caffeine the secret to better exercise? Find out what the research says.

What are the benefits of caffeine before a workout?

Caffeine before a workout may boost mental and physical performance in several ways.

Reduces fatigue

Caffeine is a natural stimulant that activates the central nervous system. It works by blocking adenosine, a neurotransmitter that makes you feel relaxed and sleepy. If you’re feeling tired when you’re supposed to head to the gym, coffee can make you feel more energized and motivated.

During exercise, caffeine may keep you going because it’s still blocking those adenosine receptors. It may also affect hormones and neurotransmitters that make you feel more awake and energetic. For example, one study found that caffeine raised levels of dopamine after participants ran on a treadmill. Low levels of dopamine can make you feel tired and unmotivated.

Increases endurance

Endurance is your body’s ability to keep going during exercise. It includes how well your heart and lungs can transport oxygen through your bloodstream to your muscles and your muscles’ ability to use it.

Experts aren’t sure how caffeine increases endurance. Its effects on the central nervous system play a role. Caffeine may also prevent calcium loss, which can lead to early fatigue.

Some research shows that caffeine helps preserve muscle glycogen or energy stores. You use glycogen for energy during exercise. When it’s low, your muscles get too tired to keep moving. But this theory is still up for debate.

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A boost in VO₂ max might also play a role. VO₂ max, or maximal oxygen consumption, measures how well your body uses oxygen during exercise. A high VO₂ max is a good indicator of cardiovascular fitness and aerobic endurance. In one study, caffeine consumption increased VO₂ max in a small group of elite athletes. It also boosted their performance in high-intensity endurance activity. And it increased their time to exhaustion, or how long the athletes could exercise before becoming too tired to continue.

Finally, caffeine may reduce mental fatigue, especially during endurance activities like running and cycling for long periods. It’s important to note that most research suggests that caffeine may have only a minor effect on endurance. In other words, it won’t take you from a 10K to a marathon. Caffeine is likely more useful for athletes who compete in events in which every second matters.

Boosts muscle strength and power

In activities that require muscular strength and power, caffeine might also help your performance. A meta-analysis found that consuming caffeine before a workout may improve isokinetic strength. This strength-training method focuses on a specific type of muscular contraction, so the results can’t be applied to all types of strength exercises.

Another study found that caffeine can increase muscle strength and power. It was shown to boost upper-body muscle strength and power. And the benefit may be more significant for sports like powerlifting. The authors also concluded these effects could apply to other sports. This includes activities that involve jumping.

Research shows that caffeine’s effects might be especially useful in competitive sports. Small increases in performance can give an athlete an edge.

May increase calorie burn

Caffeine has been shown to increase metabolism and reduce fat mass. In fact, it’s a key ingredient in many weight-loss pills.

Practically speaking, if coffee before a workout gives you the energy to get to the gym and work out harder and longer, you’re going to burn more calories than you would taking a nap or doing a quick unenthusiastic workout.

Physiologically, caffeine can also boost the calories you burn in the period following your workout. After you exercise at a high intensity, your body continues burning calories at a higher rate while it recovers. This exercise afterburn is called post-exercise oxygen consumption (EPOC).

The harder you work out, the more calories you’ll burn in the post-exercise period. Caffeine can increase the afterburn. In one study, EPOC was 15% higher after a bout of high-intensity strength training in participants who consumed caffeine preworkout compared with a placebo.

It’s possible that coffee also has a placebo effect. You associate coffee with feeling more alert and awake. Because you anticipate the stimulant effects, you’ll feel that boost regardless of the actual physical effects on your brain and body.

How much caffeine is advised before working out?

Research shows that doses of 3 mg to 6 mg of caffeine per kilogram of body weight about an hour before working out has the best results. For a 150 lb person, that’s 204 mg to 408 mg of caffeine.

An 8 oz cup of coffee has 80 mg to 100 mg, which means you’d need to drink 2 to 5 cups of coffee before you head to the gym. That’s not doable for most people.

Many athletes opt for caffeine supplements. Some of these come in pill form, and many preworkout drinks also include caffeine.

What are the side effects of caffeine before exercise?

The FDA recommends consuming no more than 400 mg of caffeine per day. It’s easy to go over that with supplements.

High doses of caffeine can cause side effects, including:

• Restlessness

• Shakiness

• Anxiety

• Insomnia

• Headaches

• Fast heart rate

• Dehydration

You might also become dependent on caffeine, so that you need increasingly more of it to get its effects.

Some people are more sensitive to caffeine, which means even small amounts can cause unwanted effects. To be sure caffeine doesn’t negatively affect you, increase the amount you consume before your workout slowly.

In any amount, caffeine too late in the day can keep you awake at night. Research suggests that you should avoid caffeine for 6 hours before bedtime. Not getting enough sleep can negatively affect your workout performance and counter any benefits you might get from caffeine.

Talk to your doctor before increasing your caffeine intake. People with certain health conditions should not have a lot — or any — caffeine. This includes people with anxiety disorders and heart problems. Pregnant people should limit their daily caffeine intake to 200 mg. Some research shows that higher intakes can cause miscarriage or preterm birth.

Why trust our experts?

Written by:

Jody Braverman, CPT, RYT

Jody Braverman has worked in the health and fitness industry –– as a trainer, yoga teacher, nutrition and lifestyle coach, writer, and editor –– for more than two decades. She graduated with a B.A. from the University of Maryland and maintains several accredited certifications.

Edited by:

Lauren Savage, MA

Lauren Savage, MA, is a health editor at GoodRx, where she focuses on movement, exercise, and healthy aging. She aims to provide readers with the information they need to live healthier, more active lifestyles.

Reviewed by:

Sanjai Sinha, MD

Sanjai Sinha, MD, is a board-certified physician with over 20 years of experience. He specializes in internal medicine.

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