Most people have experienced the jolt of caffeine; perhaps you start every day with a dose in your morning cup of coffee. While no doubt you know that caffeine makes you feel more alert, you probably don't even think about the other ways caffeine impacts your body. In truth, caffeine is a stimulant that affects multiple body systems. In particular, caffeine can increase your heart rate.
Caffeine Basics
To understand how and why caffeine affects your heart rate, it's helpful to know what caffeine really is. Caffeine is a chemical compound that is scientifically known as trimethylxanthine. It occurs naturally in a number of plants, such as cacao, yerba mate and tea trees, where it keeps pests away. For humans, caffeine is an addictive stimulant. Although it is commonly consumed in coffee, tea, soda, energy drinks, chocolate and some medications, it can also be harmful at times.
Caffeine and Heart Rate
All stimulants raise your heart rate, and caffeine is no different. Harvard Medical School states that while caffeine is often harmless and can even be beneficial in some circumstances, it is also known to increase heart rate, blood pressure and risk of irregular heartbeat. However, it's impossible to determine one average heart rate for a person who is under the influence of caffeine, for two reasons. First, normal resting heart rates -- while not on caffeine -- are extremely variable, ranging from 60 to 100 beats per minute, according to Dr. Edward R. Laskowski of the Mayo Clinic. And second, the increase in your heart rate as the result of ingesting caffeine will vary depending on how much caffeine you consume. Therefore, your typical heart rate with caffeine may be very different from someone else's.
Safety
While it is known that caffeine speeds up your pulse, caffeine is generally considered safe when consumed in moderation. Princeton University Health System notes that the average adult consumes about 200 mg of caffeine per day, roughly the equivalent of 2 cups of coffee. According to MayoClinic.com, you should consider cutting back on your caffeine intake if it totals more than 500 mg per day.
Precautions
Some individuals are more sensitive to caffeine than others, and may experience adverse side effects from a much smaller caffeine dosage than expected, even a dosage normally considered safe. If you experience unpleasant effects from ingesting caffeine, you may wish to avoid it. If you have concerns about your heart rate while on caffeine, speak with your doctor. If you experience worrisome heart sensations such as palpitations or extreme racing heart, seek medical attention immediately.
References
- University of California, Berkeley Cal Dining; The Ups and Downs of Caffeine; May 2005
- Harvard Medical School; Coffee Health Risks: For the Moderate Drinker, Coffee is Safe Says Harvard Women's Health Watch; August 2004
- MayoClinic.com; Heart Rate: What's Normal?; Edward R. Laskowski, M.D.; September 2010
- Princeton University Health Services: Drugs and Smoking
- MayoClinic.com; Caffeine Content for Coffee, Tea, Soda and More; October 2009
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