Many of us reach for that morning cup of joe to start our days. But it turns out that caffeine may do more than just help you wake up and stay alert—it can boost athletic performance. 

In this article, we’ll answer your most pressing questions about caffeine’s effect on athletic performance, who might benefit from consuming it, how much and what form to take, and when to take it for optimal results.  

What Is Caffeine?

Caffeine is a naturally derived stimulant that increases the activity of the central nervous system, muscles, and other organs.1 It is the most widely consumed psychoactive substance in the world, with approximately 90% of adults in western countries consuming the drug daily, typically through coffee, tea, or sodas.2 Research suggests that in moderate doses, caffeine may provide many benefits for the human body by increasing physical and mental performance.2,3

How Does Caffeine Affect Performance?

Coffee lovers will be happy to hear that caffeine can significantly improve athletic performance in endurance activities like running and biking and strength training exercises. Caffeine enhances arousal and vigor by stimulating the central nervous system while reducing exercise fatigue.1 

Caffeine also lessens the perception of pain and exertion.1 Many studies suggest taking caffeine before exercise can increase muscular strength and endurance, sprinting, jumping, throwing performance, and both aerobic and anaerobic actions.2 

Beyond physical performance, caffeine also enhances cognitive function, which can give you an edge in everyday activities and exercise.2 A 2016 review found that caffeine enhanced attention, vigilance, and reaction time, which can all improve physical performance.4 

Importantly, caffeine intake appears to enhance athletic performance in people of all training levels.2 So, whether you are an elite athlete or novice exerciser, caffeine may help you improve!

When Should I Take Caffeine?

After reviewing numerous studies, the International Society of Sports Nutrition concluded that supplementing with caffeine about 60 minutes before exercise provides the most benefit.2 However, consuming caffeine during the later stages of your workout may help combat fatigue during more prolonged bouts of exercise. 

A recent review of studies found that caffeine improved performance more when athletes took it closer to times of more significant fatigue. If you are competing in a long race, such as running or cycling, you may get more of a boost by waiting to ingest caffeine in the later stages of the race.6

The most effective time to ingest caffeine depends on how you consume it. Caffeine comes in many forms—from a cup of coffee to caffeinated beverages and even caffeinated gum. Your body absorbs the caffeine from these products at different rates. For example, your body absorbs caffeine from chewing gum much faster than from caffeinated beverages.6  

Genetics may also influence how quickly your body absorbs and feels the effects of caffeine. Peak caffeine concentrations can range anywhere from 30 to 120 minutes, so it is essential to monitor your body’s individual response to caffeine if you are using it to enhance physical performance.2

Although caffeine can help improve your workout performance, you may want to skip the caffeine if you exercise in the evening. Consume caffeine as early as you can in the day to avoid disturbing your sleep.1,2 

What Are the Sources of Caffeine?

The most common sources of caffeine are beverages such as coffee, tea, and soft drinks. About 96% of the caffeine we consume comes from these drinks—but these days, there are many other caffeine products on the market.2 Pre-workout drinks, energy drinks, caffeinated gum, caffeine capsules, mouth rinses, caffeinated energy bars or gels, and nasal sprays are all common forms of caffeine supplementation.2

How Much Caffeine Is Best?

Studies show that doses between 3 to 6mg of caffeine per kilogram of body weight—or 1.4 to 2.7mg of caffeine per pound of body weight—improve exercise performance.2 For example, the recommended dose for a person weighing 154 pounds (70kg) is 210 to 420mg of caffeine before exercise. 

Generally speaking, a dose of around 200mg of caffeine is usually sufficient for improving athletic performance.3 For reference, an 8-ounce cup of coffee contains about 90mg of caffeine, a caffeinated 12-ounce soda contains about 35mg, and most energy drinks and pre-workout supplements can range between 150 to 300mg of caffeine.7

To determine whether a supplement or beverage contains caffeine, look at the supplement facts panel. Often the label will list caffeine and provide the dosage. Still, other ingredients that may provide caffeine include cocoa, green coffee bean, guarana, kola nut, methylxanthine, tea, green tea extract, xanthine, or yerba mate.3

Keep in mind that some caffeine supplements can be very potent. Just one tablespoon of caffeine in pure powder contains 10g (10,000mg) of caffeine, equivalent to about 28 cups of coffee. Doses between 10 to 14g can be toxic, leading to seizures or even death—so proceed with caution when using caffeine in its pure powder or liquid form.1,7

As always, check with your physician or other qualified healthcare providers before adding new supplements to your regimen. 

Can You Have Too Much Caffeine?

If you are a coffee lover, you may be disappointed to know that too much caffeine can be harmful. 

Consuming over 500mg of caffeine daily can decrease physical performance rather than enhance it due to potential sleep disturbances.1 High levels of caffeine can interfere with sleep by reducing the quality, duration, and efficiency of sleep and making it more difficult to fall asleep.9 This can lead to chronic mild or moderate sleep deprivation. 

This pattern may not sound severe, but even mild sleep deprivation can affect athletic performance.2 Mild to moderate sleep deprivation may alter appetite and how the body uses protein, attention, learning, and memory.10 Quality sleep is essential for mental and physical recovery from exercise—without it, performance can greatly decline.2

Caffeine’s effect on sleep largely depends on when you consume it. Caffeine typically has a half-life of about 4 to 6 hours. Practically, this means you should stop consuming caffeine about six hours before bedtime and, ideally, consume it as early in the day as possible to avoid sleep disturbances.2 

In addition to affecting sleep quality, excess caffeine can also cause irritability, anxiety, restlessness, nausea, vomiting, increased heart rate, and headaches.1,2 These side effects can negatively impact exercise performance and overall well-being, so it is essential to know your limits when supplementing with caffeine. 

Though you may have heard that caffeine alters the fluid balance in the body, this is false.1 Caffeine does not dehydrate you or increase sweat loss. Hydration is always essential when exercising, and caffeinated beverages can contribute to fluid intake. 

The US Food and Drug Administration (FDA) states that 400 mg of caffeine daily does not cause any adverse side effects. The American Medical Association (AMA) recommends that adults consume no more than 500 mg of caffeine daily.1 By keeping these guidelines in mind, most adults can use caffeine safely and effectively before exercising. 

Can Everyone Use Caffeine?

Most people can tolerate caffeine, but specific populations may want to restrict their intake. 

The American Academy of Pediatrics (AAP) recommends that children under 12 should avoid all caffeine. The AAP states that adolescents 13 years and older may consume up to 100mg of caffeine daily.11 

According to the American College of Obstetricians and Gynecologists, pregnant women should limit their intake to 200mg of caffeine daily.11

Takeaway

If your workouts are plateauing, consider supplementing with caffeine to see whether it improves your performance. Just remember to limit your intake to no more than 500mg daily and stop using caffeine by the afternoon to avoid disturbing your sleep. 

Coffee, pre-workout supplements, or caffeinated gums or gels are all popular forms of caffeine that should have strong enough doses to help boost your athletic performance. According to the FDA, caffeine can be used safely and effectively daily to help improve your workouts. 

References:

  1. Office of dietary supplements - dietary supplements for exercise and athletic performance. NIH Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/ExerciseAndAthleticPerformance-HealthProfessional/#caffeine. Published June 2, 2022. Accessed August 15, 2022. 
  2. Guest NS, VanDusseldorp TA, Nelson MT, et al. International society of sports nutrition position stand: caffeine and exercise performance. J Int Soc Sports Nutr. 2021;18(1):1. Published 2021 Jan 2. doi:10.1186/s12970-020-00383-4
  3. Caffeine for performance. Operation Supplement Safety. https://www.opss.org/article/caffeine-performance. Published April 30, 2022. Accessed August 15, 2022. 
  4. McLellan TM, Caldwell JA, Lieberman HR. A review of caffeine’s effects on cognitive, physical and occupational performance. Neurosci Biobehav Rev. 2016;71:294–312. doi: 10.1016/j.neubiorev.2016.09.001.
  5. Shen JG, Brooks MB, Cincotta J, Manjourides JD. Establishing a relationship between the effect of caffeine and duration of endurance athletic time trial events: a systematic review and meta-analysis. J Sci Med Sport. 2018. 
  6. Kamimori GH, Karyekar CS, Otterstetter R, Cox DS, Balkin TJ, Belenky GL, et al. The rate of absorption and relative bioavailability of caffeine administered in chewing gum versus capsules to normal healthy volunteers. Int J Pharm. 2002;234(1–2):159–167. doi: 10.1016/S0378-5173(01)00958-9.
  7. Spilling the beans: How much caffeine is too much? U.S. Food and Drug Administration. https://www.fda.gov/consumers/consumer-updates/spilling-beans-how-much-caffeine-too-much. Published December 12, 2018. Accessed August 15, 2022. 
  8. Does taking a pre-workout actually work? Cleveland Clinic. https://health.clevelandclinic.org/does-taking-a-pre-workout-actually-work/. Published September 10, 2020. Accessed August 15, 2022. 
  9. Clark I, Landolt HP. Coffee, caffeine, and sleep: a systematic review of epidemiological studies and randomized controlled trials. Sleep Med Rev. 2017;31:70–78. doi: 10.1016/j.smrv.2016.01.006.
  10. Halson SL, Juliff LE. Sleep, sport, and the brain. Prog Brain Res. 2017;234:13–31. doi: 10.1016/bs.pbr.2017.06.006.
  11. Caffeine. The Nutrition Source. https://www.hsph.harvard.edu/nutritionsource/caffeine/. Published November 12, 2020. Accessed August 15, 2022.