
For many people, having a cup of coffee in the morning is life. It’s what gets the body moving and brain energized in the morning or mid-day when the energy starts to lull. What amount is needed for a boost to athletic performance or in your workouts? When to take it? And what is the best or different sources of caffeine?
What is Caffeine
Caffeine naturally is found in over 60 plant species, of which cocoa beans, kola nuts, tea leaves and coffee beans are the most well-known.
Sources of Caffeine
Coffee: 1 cup typically has 100mg of caffeine, while decaff contains 4mg
Espresso: 1 shot or 1.5 ounces contains about 65mg caffeine
Tea: 1 cup of black tea contains about 47mg caffeine, green tea 28mg, decaff 2mg, and herbal tea contains none.
Soda: A standard 355mL or 12-ounce can contain about 40mg caffeine
Chocolate: 1 ounce of dark chocolate contains about 24mg caffeine, milk chocolate about 6mg.
Guarana: A seed from a South American plant processed as an extract has 4x the amount of caffeine found in coffee beans.
Energy Drinks: 1 cup or 8 ounces contains about 85mg, but most energy drinks are 16 ounces containing 170mg caffeine.
Supplements: Caffeine pills or pre-workout powders generally contain 100-150mg caffeine per serving/scoop. There are also chewing gums and caffeine containing gels.
Benefits
- Muscular endurance
- Movement velocity (power) and muscular strength
- Sprinting, jumping, and throwing performance
- Wide range of aerobic and anaerobic sport-specific actions
Recommended Amounts
- 3–6 mg/kg body mass
Examples: 150 lb person ~200-400mg caffeine or 200 lb person ~270-540mg caffeine
Timing (Absorption and Metabolism)
Caffeine is absorbed within about 45 minutes after consuming, and peaks in the blood anywhere from 15 minutes to 2 hours.
- For a boost in athletic performance the recommendation is 45-60 minutes before exercise.
Caffeine Sensitivity
Some people are more sensitive to caffeine than others. Always start with a lower dose of the range such as 3mg/kg body weight to test your tolerance first.
Caffeine Tolerance
If you’re drinking several cups of coffee or 1-2 energy drinks in a day your “caffeine tolerance” may be quite high like it can be for alcohol with people who drink often.
It’s best to cycle your sources of caffeine and have lower days than others to see the full benefits. Even taking breaks from caffeine for a week can reset your tolerance and therefore sensitivity to caffeine.
*Note: One thing to remember is the timing of these products before training or sports, and that it will be absorbed much faster when on an empty stomach.
The Best Sources for Exercise
Three different sources of caffeine can be great for avoiding such tolerances and giving your body a break from the higher doses.
Some workout days you may only need a small amount to keep your brain focused, while others will require more of a boost for intense training.

Energy Fizz Sticks
– Caffeine sources from green tea and guarana
– No peak and crash
– Great for an added energy boost and brain focus
Coffee
– Higher concentration of caffeine
– Generally a quicker spike in energy followed by a crash (if consuming 2+ cups in a short period of time)
Pre-Workout Supplements
– This example is 150 (1 scoop) to 300mg (2 scoops) of caffeine anhydrous (dehydrated caffeine powder)
– Quick and convenient way to get a high dose of caffeine
– Powder, easier to mix with water in any concentration desired
Like with your training make sure and find what works best for you and your individual tolerance. Cycling and taking a week long break can reset your caffeine tolerance to still see a benefit without continued increases in dosage.
References
Guest, N.S., VanDusseldorp, T.A., Nelson, M.T. et al. International society of sports nutrition position stand: caffeine and exercise performance. J Int Soc Sports Nutr 18, 1 (2021). https://doi.org/10.1186/s12970-020-00383-4
Harard T.H. Chan. School of Pubic Health. The Nutrition Source: Caffeine. https://www.hsph.harvard.edu/nutritionsource/caffeine/