What’s the Optimal Timing of Caffeine for Physical Performance?

Caffeine is one of the world’s most widely consumed stimulants and holds a special, almost ritualized place in the routines of millions of people worldwide. In Western countries, a staggering 89% of adults regularly consume caffeine, with an estimated daily intake of around 200 mg for men and women.¹ More recently, caffeine isn’t just confined to a morning cup of coffee or tea; it’s now in energy drinks, supplements, gels, gum, and aerosols.

Beyond the immediate effects of caffeine, research now suggests there is a strategic time to ingest caffeine throughout the day to optimize its performance benefits.

Timing Matters: Matching Caffeine with Fatigue

A common misconception among athletes is that large doses of caffeine before exercise will transform them into powerhouses. In reality, smaller doses tend to be more effective, especially when consumed at the onset of fatigue.

Instead of taking a large dose before exercise, Dr. Louise Burke recommends using caffeine as you’re starting to feel fatigued.² Small doses of caffeine (around 3 mg/kg)³ tend to work well. For a 150-pound athlete, that amount of caffeine is approximately equivalent to the 200 mg often found in a caffeine supplement pill. However, you will need to experiment to determine what works best for you.⁴ More about that in a bit.

Caffeine’s primary function in this context is to mask the sensation of fatigue, enabling athletes to maintain their endurance for longer periods of time. In fact, studies have shown that caffeine enhances endurance by 2-4% on average across various sports like cycling, running, cross-country skiing, and swimming.⁴ The literature suggests that endurance sports benefit the most from caffeine, with smaller improvements seen in anaerobic activities (short, intense workouts).^4,5

Endurance sports like cycling benefit the most from well-timed caffeine ingestion. Adobe Photos/Davd Fuentes

So does abstaining from caffeine maximize its benefits? Historically, athletes have thought “oh, caffeine is a substance where I build up a tolerance, so I must keep increasing in dose to ‘feel’ the effects I want.” This is why some people used to practice caffeine withdrawal prior to events – they aimed to reintroduce the stimulating boost. 

However, the research on caffeine habituation and performance effects in athletes is “surprisingly small” with support for both sides.^6,7 Given the variability of data, it’s advisable for athletes not to prioritize it as their main concern.

Limiting caffeine before an event to “get more from your caffeine” is not particularly helpful, said Dr. Burke. In one study, ingesting 3 mg/kg of caffeine significantly improved exercise performance in 12 trained cyclists regardless of whether or not the athletes had abstained from caffeine for 4 days before a performance test.⁸

Still, caffeine may not be for every athlete…

Personalized Strategies: Me-Research

One crucial takeaway from recent research is that there’s no one-size-fits-all approach to caffeine consumption. Individuals vary in their response to caffeine, with some experiencing substantial performance benefits, others minor effects, and some even negative effects like increased heart rate and nervousness during competition or sleep disturbances that inhibit recovery. 

Adenosine is a neurotransmitter that helps promote the drive to sleep and is also a byproduct of burning energy, as happens during exercise. One of the ways that caffeine works is it binds to the same receptors that adenosine typically targets in our central nervous system and, as a result, inhibits the onset of drowsiness that usually accompanies rising adenosine levels in the body. The amount and activity of these receptors vary from person to person. 

Additionally, there are enzymes in our liver that break down caffeine and help us excrete it from our system.¹¹ “The activity levels of these enzymes in our liver may also differ among individuals,” said Dr. Burke, “which means you may be a fast metabolizer where caffeine’s effect is removed more quickly. Or you may have a slower metabolism and caffeine may linger in your system for longer.”

The enzyme CYP1A2, in particular, is responsible for metabolizing and breaking down caffeine. The activity and protein levels of CYP1A2 can be influenced by an interplay between environmental and genetic factors, which can lead to significant variability in how a person experiences caffeine’s effects.^7,12

Caffeine also promotes the release of epinephrine from the adrenal glands, which can help speed the rate of muscle contraction, increase heart rate, and increase the release of free fatty acids for energy.¹³

“What we’re asking people to do is not think of themselves as an athlete and as a person as separate things,” said Dr. Burke. “We’re not saying to people who are already caffeine consumers to have more because you’re an athlete. We’re saying, ‘take the caffeine that you may already consume in a day and organize its timing so that you optimize your performance benefits.’”

How we metabolize caffeine might also change as we age. The “me-research” of today may not be relevant to me-research in 10 to 20 years from now. Our experience with caffeine’s effects is a lifelong, self-learning journey.

What Time Does Your Sport Start?

Apart from genetics, it’s important to take into consideration the timing of your physical activity. If you’re an athlete whose games take place at night (e.g., football), experiment with not having caffeine before the game. Instead, make decisions about whether you need caffeine based on how you’re feeling in the game. This way you can maximize your sleep and recovery after.

If your sports events take place at night, consider using caffeine only when you’re fatigued. Otherwise, it could disrupt your sleep recovery. Canva Images

To avoid sleep issues, according to a systematic review and meta-analysis by Dr. Burke and colleagues, “coffee (107 mg caffeine per 250 mL) should be consumed at least 8.8 hours prior to bedtime and a standard serve of pre-workout supplement (217.5 mg caffeine) should be consumed at least 13.2 hours prior to bedtime,” with adjustments made on an individual as-needed basis.¹⁴ 

All in all, caffeine in small doses and timed during the onset of fatigue may help some athletes perform better, but it’s also clear that there is no one-cup-of-tea approach for success.