5 A Part of Hearst Digital Media

It can be more than just a morning pick-me-up. Caffeine has a number of physiologic effects that can help improve athletic performance. It is rapidly absorbed in the gastrointestinal tract and is a mild stimulant that affects multiple organ systems. 

While there is no consistent evidence for adverse effects on a healthy cardiovascular system, some athletes—like those with preexisting heart conditions, pregnant women, or those on certain medications—should limit their intake. And just like you discovered in college while pulling an all-nighter, if you consume too much caffeine, sleeplessness and jitters are likely to occur (especially in people not used to caffeine). As for leaching the calcium out of your bones? No convincing research links caffeine to osteoporosis.

Caffeine is known to increase circulation of free fatty acids, which means that it’s glycogen sparing. And studies show that supplementation of caffeine (between 3-6mg/kg) is effective in reducing perceived exertion (meaning that six-minute mile feels like a seven-minute mile). In fact, studies have found that swimmers are faster after 6mg/kg body weight administered in a fruit juice drink two- to five hours before the swim and reported lower perceived exertion. And cyclists’ time to exhaustion was nearly 15 minutes longer while caffeinated with 330mg caffeine one hour before exercise.

Three to 6mg/kg body weight is recommended for endurance exercise (and more is not necessarily better—benefits do not rise with higher dosages). More pronounced effects might be perceived if you abstain from caffeine for several days before the exercise, but if you simply can’t live without your morning cup of joe, the research isn’t compelling enough to force you to forego it. 

According to What Is a Shoey, Starbucks espresso (75mg/shot), black tea (30-80mg/8oz), green tea (35-60mg/8oz), and even in novel product like flavor enhancers like Mio Energy drops. (One squeeze = 60mg.)

Many runners rely on caffeine-laced gels, blocks, and beans for a mid-run pick me up. Because there are many levels of caffeine in these products, always be careful to check the label of your favorite flavor to see how much it might contain. In general, if a product contains caffeine, it likely offers somewhere between 25-100mg per serving. Athletes who don’t often use caffeine but want to try out a mid-run fuel with some kick would do well to start with a conservative 25mg dose and see how they respond. 

Remember, while you may find that caffeinated fuel is just the kick you need to make it through a long run or race, the effect of this ergogenic aid can be cumulative. So if you consume double-espresso gels every hour of a long run, you should plan on staying up past your bedtime or until the post-run jitters wear off.

* * *

Walking Could Add 11 Years to Your Life, Study, MS, RD, CSSD, LD, is a registered dietitian and a board-certified specialist in sports dietetics who holds a Bachelor’s Degree in Dietetics from Miami University (Ohio) and a Masters Degree in Medical Dietetics from The Ohio State University. Pamela is co-owner of Heres Exactly What to Eat Before a Half Marathon, a Dayton, Ohio-based nutrition consulting firm that serves teams and individual athletes. Pamela has finished one Ironman Triathlon and 14 marathons, including the Boston Marathon, and has a PR of 3:09.