How Caffeine Improves Exercise Performance

man running on sand field

We’re all familiar with coffee as a great way to pep up our performance at work and school or make getting ready for a long day a little easier. And most of us know it is a little something called caffeine that helps put that extra pep in our step. But how much do you know about caffeine and what it does in our bodies? Have you ever noticed how many sports performance boosters use caffeine? And even flu meds? That’s because there’s some solid science suggesting it can give to sports performance. Curious? Let’s take a look.

Coffee Beans and Caffeine: A Closer Look

Let’s start with the basics- how much caffeine does a coffee brewed from beans contain?  It varies by several factors, including the exact coffee beans used, the bean’s origin, and how it’s roasted and processed. Generally, Arabica coffee beans, which are known for their milder and more nuanced flavours, tend to have lower caffeine content compared to Robusta coffee beans, which are often more bitter and have a stronger taste.

  • Arabica Coffee Beans contain about 1.2% to 1.5% caffeine by weight. This translates to roughly 60 to 80 milligrams of caffeine per 8 grams of ground Arabica coffee, about a single shot.
  • Robusta coffee beans have a higher caffeine content, averaging around 2.2% to 2.7% caffeine by weight. This means about 100 to 120 milligrams of caffeine per 8 grams of ground Robusta coffee.
  • This means the average cup of brewed coffee (about 240 ml) contains around 80 to 100 milligrams of caffeine

A lot can affect the precise amount of caffeine in a cup, with light roasts being slightly more caffeinated, and with cold-brew coffees containing more than other brewing styles.

What Does Caffeine Do in the Body?

Caffeine absorbs very quickly within the body. Its effects peak between half an hour and two hours later. It will stay at this peak for about 4 hours before declining.

Unlike many substances, caffeine acts across a wide range of cells in the body, from muscle to the central nervous system and even fat cells! It helps:

There’s also some evidence that it can help save your glycogen stores, the ‘food’ your muscles use, possibly by making it easier to burn fat for energy.

crop faceless man drinking coffee in cafeteria
Photo by Gary Barnes on

Caffeine and Sport: The Links

You’re probably getting an idea already how this simple component of coffee beans can make an impact on how you perform athletically just by seeing this list. In fact, it was once on the banned list for athletes, although that changed in 2004.

One large-scale study covering data from over 50 other studies suggests that the improvement in performance using caffeine can be up to 16%, getting more effective the longer the exercise. This makes sense- if it reduces pain and fatigue and boosts focus, you’d see better effects over time in exercise.

But the exercise category matters as well. In sports where muscular endurance is key, it may boost performance by up to 7%. For strength-based sports, we see a lot less, averaging about 2-7%. For quick, short sports like sprints, there’s very little perceptible boost. But, interestingly, it has a bigger impact on team sport performance, too. This makes sense, as you need to use more thinking and be more ‘awake’ when competing in a group.

Should I Use Caffeine for Exercise Performance?

So if you’re looking to get the last few drops of great performance out of your body, caffeine might be the sports supplement to help you do it. But it isn’t quite that simple! We still need to talk about doses. Most of the best studies on caffeine and exercise performance use doses between 3-6 mg of caffeine per kilo of body weight.

That’s…rather a lot of cups of coffee! Remember, it’s between 80-100 mg per cup of coffee brewed from coffee beans, with many factors affecting it. Anything over 9 mg/kg produced no extra benefit but came with side effects like tummy troubles, irregular heartbeat, and anxiety.

Does that mean you should rush out and get a coffee machine to further your sporting goals? Well, we’d always say the simple joy of a great cup of coffee is its own reward! If you want to get the ultimate sports performance out of your body you might benefit from considering caffeine into your training program. If your sport is aerobic and long-term, so much the better- and we have solid science to back it up.

But remember, most of these studies do focus on elite athletes who need to squeeze the very best out of their training programs. And who are likely using caffeine pills to fine-tune their dose and ensure they time their caffeine intake perfectly. Few of us are competing at these sorts of levels. But if you’re a coffee lover and keen sportsman, there’s no harm in enjoying a great brew. Pop it about half an hour before you hit the gym or the track. And it’s always wonderful to find another good reason to enjoy your favourite roasts, right?

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