~ Annie Bothma, Elite Athlete, IOPN Performance Sports Nutritionist (EQF Level 7. Masters), Running & Strength Coach
Caffeine is a powerful and widely-used ergogenic aid that can enhance both physical and mental performance in athletes. From boosting endurance to sharpening focus, caffeine has long been a favorite among athletes seeking an edge.
In this post, I will explore the mechanisms behind caffeine's effectiveness, its optimal dosage, key considerations, and practical advice for implementing caffeine in your athletic routine to optimize performance.
Mechanisms of Action
Caffeine’s primary ergogenic effect comes from its ability to block adenosine receptors in the brain. Adenosine is a neurotransmitter that promotes relaxation and drowsiness. By inhibiting adenosine’s effects, caffeine increases the release of dopamine and norepinephrine, which leads to heightened alertness, reduced perception of effort, and increased focus during exercise.
Beyond its impact on the central nervous system, caffeine can also potentially improve fat mobilization, helping the body use fat as a fuel source during endurance exercise. This can delay the depletion of muscle glycogen stores, allowing for sustained energy levels throughout prolonged physical efforts.
Optimal Dosage & Timing of Caffeine
The optimal dose of caffeine for performance enhancement typically ranges from 3-6 mg/kg of body weight, which equates to about 200-400 mg for a 70 kg athlete. Research has shown that even doses as low as 2 mg/kg can provide a boost in endurance.
Timing is also critical. Caffeine reaches its peak concentration in the blood about 45-60 minutes after ingestion, so it’s recommended to consume caffeine 30-60 minutes before training or competition. For longer events lasting more than three hours, athletes may also benefit from "topping up" with smaller doses of caffeine during the event to maintain its ergogenic effects.
Here’s a table with the recommended daily caffeine intake for different age groups and athletes.
Age Group | Recommended Caffeine Intake |
<12 years | None |
12-18 years | 100-200 mg daily |
Adults (18+) | Up to 400 mg daily |
Athletes | 3-6 mg/kg of body weight |
Key Considerations Before Using Caffeine
While caffeine offers many benefits, it is not without potential downsides. Individual responses to caffeine vary greatly depending on genetics, habitual consumption, and caffeine sensitivity. For example, athletes with certain genetic variations in the CYP1A2 gene metabolize caffeine more slowly, which can lead to increased anxiety or insomnia.
Moreover, athletes should be mindful of caffeine's impact on sleep. High doses or late-day consumption can interfere with sleep quality, which is critical for recovery. In fact, regular users of caffeine might find that its performance-enhancing effects diminish over time as tolerance builds.
Caffeinated Beverages
After water, coffee is the second most popular beverage globally! Similar to many endurance athletes I work with in my nutrition practice, I also enjoy having my morning coffee before my training session. It provides comfort and helps me start my day. For those who enjoy their morning cup of coffee, I recommend consuming fluids like electrolytes or water and having their pre-run meal or snack before indulging in their coffee.
The caffeine content in coffee can vary significantly depending on the brewing method as well as the type of roast used. Light roast coffee may have slightly more caffeine by volume. Dark roast coffee will have slightly less caffeine if compared by weight.
Here’s how different methods can affect the amount of caffeine:
Espresso: Typically, a shot of espresso (30-50ml) contains around 63 mg of caffeine. Since it’s concentrated, espresso tends to have more caffeine per ounce compared to other brewing methods, but the serving size is much smaller.
Drip Coffee: A standard cup of drip coffee (240ml/8oz) usually contains around 95 mg of caffeine, but this can vary depending on factors like the coffee bean, grind size, and brewing time.
French Press: French press coffee tends to have a slightly higher caffeine content, around 80-100 mg per 8oz cup. This is because the brewing method allows for a longer steeping time, leading to more caffeine extraction.
Cold Brew: Cold brew coffee, which is brewed by steeping coffee grounds in cold water for an extended period (usually 12-24 hours), can contain a much higher caffeine concentration, sometimes over 200 mg per 8oz, depending on the coffee-to-water ratio.
Instant Coffee: Instant coffee generally has less caffeine, with about 30-90 mg per serving, depending on the brand and the strength of the brew.
Percolator: Coffee brewed using a percolator typically contains a similar amount of caffeine as drip coffee, but it can also vary depending on how long the water cycles through the grounds.
This table below includes a variety of beverages and their caffeine content, ranging from different coffee brewing methods to tea, cola, and popular energy drinks.
Beverage | Serving Size | Caffeine Content (mg) |
Espresso | 30-50 ml (1 shot) | ~ 63 mg |
Drip Coffee | 240 ml (8 oz) | ~ 95 mg |
French Press | 240 ml (8 oz) | ~ 80-100 mg |
Cold Brew | 240 ml (8 oz) | ~ 150-200+ mg |
Instant Coffee | 240 ml (8 oz) | ~ 30-90 mg |
Percolator | 240 ml (8 oz) | ~ 95 mg |
Black Tea | 240 ml (8 oz) | 40-70 mg |
Green Tea | 240 ml (8 oz) | 30-50 mg |
Cola | 330 ml (12 oz) | 34 mg |
Red Bull | 250 ml (8.4 oz) | 80 mg |
Monster Energy | 480 ml (16 oz) | 160 mg |
Practical Tips for Athletes Using Caffeine
To maximize the benefits of caffeine while minimizing risks, here are some practical tips for athletes:
Start with a lower dose: If you are new to caffeine or unsure of your tolerance, start with a lower dose, around 2-3 mg/kg, and gradually increase as needed.
Avoid late-day caffeine intake: To prevent sleep disturbances, avoid taking caffeine within six hours of bedtime. Caffeine has a half-life of around 4-5 hours, so that late afternoon cup of coffee may have you tossing and turning unable to get a good night of rest before your training session the next day.
Experiment in training, not on race day: It’s important to experiment with caffeine during training sessions to understand how your body reacts before using it in a race or competition. Remember, nothing new before race day!!
Hydrate properly: While caffeine has a mild diuretic effect, research shows that it doesn't cause significant dehydration during exercise. However, it’s still essential to stay well-hydrated, especially in endurance events to optimize both performance and avoid adverse health complications.
Consider your fuel sources: Caffeine is available in many forms, including coffee, energy gels, sports drinks, and pills. Choose the form that works best for your digestion and performance needs.
Use caffeine strategically in long events: For endurance athletes, consuming caffeine not only before but also during events lasting over three hours can help stave off mental and physical fatigue.
This table provides a quick comparison for athletes to choose the right caffeinated gel based on their caffeine needs.
Brand | Product | Caffeine Content (mg) |
Maurten | Gel 100 CAF | 100 mg |
Precision Hydration | PF 30 Caffeine Gel | 100 mg |
GU Energy | Energy Gel (variety) | 20-40 mg |
SIS Beta Fuel | Beta Fuel + Caffeine Gel | 100 mg |
Science in Sport (SIS) | Go Energy + Caffeine Double Espresso | 75 mg |
Clif Shot Energy Gel | Energy Gel with Caffeine | 50-100 mg |
Honey Stinger | Caffeinated Energy Gel | 32 mg |
PowerBar | PowerGel Shots + Caffeine | 75 mg |
High5 | Energy Gel + Caffeine | 30 mg |
Conclusion
Caffeine can be an effective tool for enhancing athletic performance, improving endurance, focus, and overall mental sharpness. However, it’s important to tailor your caffeine intake to your individual response, consider the timing, and avoid overuse to prevent negative side effects like disrupted sleep or anxiety. By understanding how caffeine works and using it strategically, athletes can harness its benefits and perform at their best.
If you are uncertain about how to properly fuel your training sessions or require a personalized race day fueling plan that includes guidance on when to incorporate caffeine, I am available to assist you. Let's work together to customize your nutrition and enhance both your performance and health.
Contact me at anniesathletes@gmail.com for more information.
Follow @annies_athletes on Instagram for more content like this.
Resources
Burke, L., B. Desbrow, and L. Spriet (2013). Caffeine for sports performance. Human Kinetics, Champaign, Illinois, USA.
Spriet, L. L. (2020). Caffeine and Exercise Performance: An Update. Sports Science Exchange, 33(203), 1-5.
Chen, B., Ding, L., Qin, Q., Lei, T-H., Girard, O., & Cao, Y. (2024). Effect of caffeine ingestion on time trial performance in cyclists: A systematic review and meta-analysis. Journal of the International Society of Sports Nutrition, 21(1), 2363789. https://doi.org/10.1080/15502783.2024.2363789.
Wang, J., Dewi, L., Peng, Y., Hou, C., & Song, Y. (2024). Does ergogenic effect of caffeine supplementation depend on CYP1A2 genotypes? A systematic review with meta-analysis. Journal of Sport and Health Science, 13(2024), 499-508. https://doi.org/10.1016/j.jshs.2023.12.005.
Wikoff, D., Welsh, B.T., Henderson, R., Brorby, G.P., Britt, J., Myers, E., & Doepker, C. (2017). Systematic review of the potential adverse effects of caffeine consumption in healthy adults, pregnant women, adolescents, and children. Food and Chemical Toxicology, 109(2017), 585-648. https://doi.org/10.1016/j.fct.2017.04.002.
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