My genetic DNA test results came back this past week. I’ll admit that although I offer this test to the public, I was hesitant to get my own results. My hesitation came down to 1 of the 45 tested genes, the CYP1A2 gene. This gene influences caffeine metabolism. Anyone who knows me well, knows that I love coffee, and I wasn’t sure that I would be willing to cut back on my caffeine consumption if I knew it was negatively impacting my health. While I tried to hold onto the philosophy of “what you don’t know can’t hurt you,” curiosity got the best of me, and I decided to ship off my saliva for testing.

Genetic DNA testing can reveal if you have the GA or AA variant of the CYP1A2 gene. The CYP1A2 gene produces an enzyme that breaks down caffeine. Those with the GA or AA variant of this gene break down caffeine more slowly than those without this risk variant. These “slow” metabolizers of caffeine have a higher risk of high blood pressure or a heart attack if they consume too much caffeine. On the other hand, “fast” metabolizers of caffeine actually have a lower risk of heart disease with moderate caffeine consumption. My genetic DNA test results showed that I have the GG variant of the CYP1A2 gene. This means that I am a fast metabolizer of caffeine… HALLELJUAH!

Caffeine is a well-known ergogenic aid, which means that caffeine consumption can enhance sports performance. Caffeine can improve sports performance by allowing athletes to exercise at a higher intensity for longer and reducing the perception of fatigue. However, new research shows that not all athletes get performance benefits from caffeine consumption. This individual difference comes down to genetics. Those who are fast metabolizers of caffeine based on their CYP1A2 gene get endurance performance benefits, while slow metabolizers do not experience the same performance benefits with caffeine consumption.

If you decide to use caffeine for a performance boost, the optimal caffeine dose is about 5 mg of caffeine per kilogram of body weight. This caffeine should be consumed about 1 hour before exercise begins. For instance, for a 65 kg athlete this would be about 325 mg of caffeine, which is equivalent to about 2-3 cups of coffee. This is a lot of caffeine to consume 1 hour before exercise. Some more practical caffeine sources include caffeine tablets, which typically contain around 200 mg of caffeine or run gum, which contains 100 mg of caffeine per pack. The legal urinary limit to caffeine in sports is 15 mcg/mL. An athlete would need to consume about 1000 mg of caffeine, the equivalent to 6-8 cups of coffee, within an hour to reach this limit.

Before using caffeine in competition, you should, as always, practice in training first. Through trial-and-error, you can determine your optimal caffeine dosage. You can also consider getting genetic DNA testing to see if you have the genetics for the endurance performance benefits of caffeine. Other consideration before caffeine usage should be its impact on your sleep since caffeine effects last for about 3-5 hours. Additionally, those who already consume a substantial amount of caffeine may require higher doses of caffeine because of reduced sensitivity.

While I don’t have any recipes related to caffeine, today is Shrove Tuesday, so check out my recipe for a healthy, but equally delicious variation of pancakes:

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Categories: Megan Kuikman

Megan Kuikman

Hello! I’m Megan Kuikman. I’m a Registered Dietitian with specialized training in sports nutrition. My goal is to help athletes and active individuals achieve a healthy attitude towards health, training, and food. I empower athletes to fuel properly for training in order to restore their health and enhance performance. You can get in touch with me at:


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