Caffeine is a stimulant that has been around for a long time and has always been a popular supplement. Most people depend on caffeine for a boost in the morning and it is also a common supplement among athletes looking to improve their performance.
While it is a well-researched supplement, there are many things we still need to learn about caffeine and how it affects certain people.
What happens to caffeine in the body?
When you drink a cup of coffee, caffeine is easily absorbed into your bloodstream and you will soon feel the caffeine kick in. There will already be a higher level of caffeine in your circulation around 15-45 minutes after you take the first few sips and it peaks around an hour afterwards. Caffeine is then metabolised (broken down) by enzymes in the liver into smaller pieces, which circulates in the body.
What effect does caffeine have on the body?
Caffeine has many effects on the body, including the central nervous system that can help to reduce the perception of pain, increase alertness, help you sustain attention and enhance mood.
However, not all people will react to caffeine the same way – it all depends on if you are a slow or a fast metaboliser.
Due to their genes, some people have a lot more of the enzymes that break down caffeine and will metabolise and clear caffeine quicker than those with lower levels of the enzymes. Fast metabolisers can usually tolerate more caffeine better and can even have a good night’s sleep after a cup of coffee.
Slow metabolisers are more sensitive to caffeine because the caffeine stays in their blood longer so the stimulatory effects will also last longer. Slow metabolisers might also be more likely to experience caffeine-related side effects like jitteriness, anxiety, and insomnia.
Remember there are many other factors that can affect caffeine metabolism and how well it works so it would be best to try it out for yourself and see how it affects you.
How can caffeine improve your performance?
Caffeine has a bunch of other effects on the body that can help to increase performance and many athletes rely on caffeine for that punch of energy when they are training. Studies have shown that caffeine can improve a variety of exercises ranging from endurance exercise to high intensity exercises and some team sports.
Caffeine can improve different components of exercise performance, including aerobic endurance, muscle strength, muscle endurance, power, jumping performance and exercise speed. 1
More specifically, caffeine supplementation before endurance exercise (running, cycling, rowing etc.) can improve your endurance capacity and reduce your perception of effort during endurance exercise, meaning it will feel like less effort to do these exercises.
When and how much caffeine do you need to improve your performance?
Most studies have shown that you need to consume about 3-6 mg caffeine/kg body weight, 30-60 minutes before training for performance benefits. However, there are also other protocols that have shown success and it would be best to determine for yourself how much caffeine and at what time works best for you.
Don’t worry if you cannot consume that amount before training. A lower caffeine dosage before exercise can also help you train better. It can improve your cognitive performance and enhance vigilance, alertness and mood during and after exhaustive exercise.
While caffeine can have many beneficial effects on the body and exercise performance, you should not overdo it because higher doses of caffeine will not be more beneficial and can cause side effects. Try to keep your daily caffeine intake below 400 mg per day or roughly 4 cups of coffee.
Is coffee a good way to consume caffeine?
While you can consume caffeine via coffee to get the ergogenic effects, caffeine is more powerful when consumed in an anhydrous state (capsule/tablet, powder). As a rule of thumb, one cup of coffee contains about 100 mg caffeine, but this can vary quite a bit, so it is difficult to know how much caffeine you are actually consuming when drinking a cup of coffee.
Caffeine is a powerful supplement with a lot of research to back it up. It might not be everybody’s cup of tea, but it is a worthwhile supplement to try out. It might just help you reach a new personal best!
 Naderi, A., de Oliveira, E., Ziegenfuss, T. and Willems, M., 2016. Timing, Optimal Dose and Intake Duration of Dietary Supplements with Evidence-Based Use in Sports Nutrition. Journal of Exercise Nutrition & Biochemistry, 20(4), pp.1-12.
 Maughan, R., Burke, L., Dvorak, J., Larson-Meyer, D., Peeling, P., Phillips, S., Rawson, E., Walsh, N., Garthe, I., Geyer, H., Meeusen, R., van Loon, L., Shirreffs, S., Spriet, L., Stuart, M., Vernec, A., Currell, K., Ali, V., Budgett, R., Ljungqvist, A., Mountjoy, M., Pitsiladis, Y., Soligard, T., Erdener, U. and Engebretsen, L., 2018. IOC Consensus Statement: Dietary Supplements and the High-Performance Athlete. International Journal of Sport Nutrition and Exercise Metabolism, 28(2), pp.104-125.