Caffeine plays a big role in the world of sport, and for good reason. As an endurance athlete, you often work with the small percentages that can make a difference to how you experience energy and fatigue along the way. Here, caffeine can be one of the tools you can use strategically – alongside your training, your energy intake, and your hydration strategy.
In the following, we gather what the research points to about caffeine and endurance and translate it into concrete steps you can test in your own everyday life. The goal is not a quick fix, but to give you knowledge so you can make informed choices about how caffeine can be part of your plan.
What research shows about caffeine and endurance
A wide range of studies and meta-analyses suggest that caffeine, for many athletes, can contribute to improved endurance performance, especially in sports such as running, cycling, and other aerobic endurance training. The effect varies from person to person and may be more or less clear depending on intensity, duration, and individual tolerance.
Typically, researchers see, among other things:
- Longer time to exhaustion at a steady workload
- Small but measurable improvements in finishing time over fixed distances
- The ability to sustain a higher intensity at the same perceived effort
The effect size is often described as a few percent in the research, but the significance depends on your sport, your level, and your form on the day. If you want to dive deeper into the underlying mechanisms, you can read the article on what caffeine does to the body, where we review possible effects on both the brain and the body.
How caffeine affects the brain, fatigue, and energy
Research points to several mechanisms that together can explain why caffeine is often included in strategies for endurance sports. It’s about both perceived alertness and how the body handles strain during activity.
- Central nervous system Caffeine affects, among other things, adenosine receptors, which are involved in the sensation of fatigue. For some, it can contribute to increased alertness and focus, which can be relevant during long or demanding training sessions.
- Perceived exertion Many studies show that some athletes experience training as less hard at the same workload after ingesting caffeine. For some, this can make it easier to sustain effort over time, without it necessarily feeling more strenuous.
- Fat oxidation and energy release Caffeine can influence the release of fatty acids via stimulation of stress hormones such as adrenaline. In theory, this can contribute to altered energy use during prolonged work, but the effect is typically moderate and depends on several factors.
The combination of altered fatigue sensation, focus, and energy handling is part of what makes caffeine relevant to test as part of your training and competition strategy.
Doses and timing in practice
When researchers study caffeine for endurance, some guidelines often recur. They can be used as a starting point, which you then adapt to your own tolerance and everyday life.
- Typical doses Many studies use around 3-6 mg of caffeine per kg of body weight before activity. For a 70 kg athlete, that corresponds to about 210-420 mg of caffeine.
- Timing before the start Caffeine is absorbed relatively quickly, and blood caffeine concentration typically peaks after 45-90 minutes. Therefore, many studies have participants ingest caffeine about 30-60 minutes before the start.
- Long competitions In marathons, triathlons, or long cycling races, many athletes work with a combination of a starting dose before the race and smaller doses later on, depending on duration, tolerability, and need.
Here, sports nutrition with caffeine can be a practical option. With energy gels with and without caffeine, for example, you can plan intake during periods where you typically want extra focus, while chews and energy chew bars for energy along the way can make it easier to distribute carbohydrates and possibly caffeine in smaller portions.
For many athletes, it makes sense to start with moderate doses, as higher doses more often increase the risk of side effects without necessarily providing a corresponding extra effect.
Individual differences in response
Even though the average in studies often points to a positive effect, athletes respond differently to caffeine. This is an important point when you plan your own strategy.
- Some notice a clear difference in alertness and perceived surplus
- Others experience only small differences in pace or watts
- A smaller group primarily gets side effects such as jitteriness, stomach issues, or discomfort related to heart-rate sensations
The differences can be related, among other things, to the following:
- Genetics, which affects how quickly and how you metabolize caffeine
- Caffeine habits, where a high daily intake can affect the perceived effect for some
- Sex, training level, and time of day, which can also influence both perceived effect and sleep
Therefore, it can be an advantage to test caffeine in training before you use it in important competitions:
- Start low, for example 2-3 mg/kg body weight
- Use it in selected training sessions such as tempo runs, long sessions, or race-like training
- Note how you respond: stomach, sleep, perceived exertion, and whether it affects your performance in practice
This way, you can tailor a caffeine strategy that suits you, or choose to prioritize other measures if caffeine doesn’t work well for you.
Choosing a caffeine source in your energy plan
In research, it is primarily the total amount of caffeine that is central. In practice, it’s also about form, taste, and ease of use when you’re training or racing.
- Coffee A cup of coffee typically contains 60-120 mg of caffeine, but the variation is large. Coffee can be relevant before training, but it is harder to dose precisely and often less practical during activity.
- Caffeine tablets or capsules Here it is easy to hit an exact mg/kg dose, and therefore they are often used in studies. On the other hand, you don’t get carbohydrates in the same solution.
- Sports nutrition with caffeine Gels, chews, and effervescent tablets with caffeine can combine carbohydrates and caffeine and are developed to be easy to use while you’re moving. They can be included as part of your overall energy and hydration plan.
An example is a caffeine gel for climbs and the finale, which provides carbohydrates and caffeine. It can be part of a planned strategy where you typically want an extra mental lift during the hard sections.
If you’d rather chew your way to the energy, a chew bar with caffeine at 50 mg per bar can be a practical choice. Here you can take a bite at a time and distribute both energy and caffeine over time, depending on need and tolerability.
If you want to see all options in one place, you’ll find an overview of our caffeine products for sport, so you can choose the form that best suits your training and your competitions.
Safety, side effects, and rules in sport
Caffeine is well researched, but requires consideration just like other sports nutrition. Side effects are seen more often at higher doses or in people who are particularly sensitive to caffeine, and it’s relevant to take this into account when you plan your intake.
- Nervousness, restlessness, or tremor, especially if you are already sensitive to caffeine
- Stomach issues such as nausea or loose stools, which can be relevant to test in training
- Palpitations or uncomfortable heart-rate sensations
- Sleep problems if caffeine is consumed late in the day
Some groups should be extra cautious with caffeine intake and may benefit from talking to a health professional before using larger amounts in connection with training or competition. This includes, among others:
- Children and adolescents
- Pregnant and breastfeeding women
- People with cardiovascular disease, arrhythmias, or high blood pressure
- Athletes with pronounced sleep problems or anxiety
- People taking medication that can be affected by caffeine
Caffeine is currently permitted in competitive sport, but may be subject to monitoring or guidelines in certain contexts. As a competitive cyclist or runner, it’s a good idea to regularly check the guidelines in your federation.
If you use dietary supplements, it’s about sticking to the recommended daily dose and choosing products from manufacturers you trust. In PurePower’s range, the caffeine content is clearly stated, both in energy products and, for example, electrolytes for optimal fluid balance, so you can keep track of the total amount, also when you combine with coffee or energy drinks during the day.
How to work with caffeine in a structured way
Research provides a framework for the use of caffeine, but it’s your body and your everyday life that determine what works. A gradual and realistic approach can help you test caffeine in a way that takes both your stomach and sleep into account.
- Get a handle on your current caffeine intake Start by getting an overview of how much caffeine you get from coffee, tea, cola, and energy drinks on a typical day.
- Start at the low end For example, test 2-3 mg/kg 30-45 minutes before an important training session. Use a gel, chew, or another product with known caffeine content so you can calculate the amount.
- Combine caffeine with a plan for carbohydrates On sessions over 60-90 minutes, it may be relevant to combine caffeine with a carbohydrate strategy, for example with energy gels with and without caffeine or energy chews, so you get energy along the way.
- Play with the timing Some endurance athletes prefer to place caffeine close to the hardest sections such as climbs, intervals, or the last part of the race. Others place part of the intake before the start and top up in smaller amounts along the way.
- Keep an eye on sleep and recovery Caffeine late in the day can affect night-time sleep. Adjust your strategy if you find that your sleep or recovery is affected.
For some, caffeine can be a useful supplement, but it doesn’t replace the foundations of performance: regular training, appropriate energy intake, and good sleep. When the basics are in place, a well-thought-out caffeine strategy can, for some, help support focus and effort in the decisive part of training or competition.