Can Caffeine Help During Exercise?

Many people enjoy caffeine in coffee, tea, cocoa and colas.  Arguably, caffeine-containing foods are part of our food culture.

Caffeine is naturally occurring in these food sources, but has an affect on the body as a mild stimulant affecting multiple organ systems.  While caffeine may be able to help keep you awake, science has shown that caffeine may also be an ergogenic aid.  Here are answers to your frequently asked questions about caffeine:

Is caffeine bad for my health? 
To name just a few areas of investigation, researchers have looked at the potential impact caffeine has on cardiovascular health, sleep, bone, cancer, weight management, metabolic disorders and pregnancy or lactation.  Here is a summary of where the science stands:
No consistent evidence for adverse effects on the cardiovascular system has been found, but people with pre-existing heart arrhythmias or high blood pressure should limit their intake.
Caffeine may interact with other supplements or drugs, such as ephedrine, so talk with your healthcare provider about potential side effects.
Caffeine may make you feel jittery or cause sleeplessness.
Stomach irritation may occur with caffeinated beverages that increase stomach acid.
There doesn’t appear to be any link between caffeine and cancer or osteoporosis.
Caffeine is unlikely to help you control your weight.
Although the relationship isn’t considered strong, coffee may help protect against type 2 diabetes and chronic disease, such as Parkinson’s.
Abstinence or moderate intake (less than 2 cups per day) is recommended during pregnancy and lactation.
Scientific literature does NOT support the notion that caffeine will cause dehydration during exercise.

How can caffeine help during exercise?
There are several ways that it’s thought that caffeine may help during exercise.  Caffeine is absorbed rapidly from the gastrointestinal tract and stimulates the central nervous system to boost awareness and to create a perception of decreased effort.  Caffeine may also act in the body to spare our stored carbohydrate (glycogen) by increasing free fatty acids into the bloodstream.  Overall, caffeine may help you feel more energized during exhaustive exercise or during sleep deprivation, provide benefits for sustained maximal endurance exercise (like in a time trial) and help with high-intensity exercise with intermittent activity over a long period of time (think soccer or rugby).

How much caffeine?  
Caffeine is a robust substance, meaning that a little goes a long way and you don’t have to be caffeine naïve to reap its benefits.  The International Society of Sports Nutrition suggests 3 to 6 milligrams per kilogram of body weight.  For example, if you weigh 180 pounds (82 kilograms), the caffeine range is 246 to 492 milligrams.

What foods and beverages have caffeine? 
Grande coffee (16 ounces), 550 mg caffeine
Tall coffee (12 ounces), 375 mg caffeine
Espresso (8 ounces), 280 mg caffeine
Over-the-counter stimulants (sold in pill form), 100 – 200 mg caffeine/pill
Black tea (8 ounces), 47 mg caffeine
Cola (21 ounce bottle), 39 mg caffeine
Green tea (8 ounces), 30 mg caffeine
Cola (12 ounce can), 21 mg caffeine
Decaffeinated coffee (12 ounces), 10 mg caffeine
Milk chocolate candy (1 ounce), 6 mg caffeine
Note: Energy drinks contain varying amount of caffeine.  Consult the Nutrition Facts panel on the packaging/product for more information.

A Registered Dietitian or a Certified Specialist in Sports Dietetics can assess your unique needs and provide you with personalized guidance.


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