Caffeine For Runners: How Much To Take And When To Take It

For many runners, caffeine is already part of everyday life. A coffee before work, a cup of tea in the afternoon or an espresso before a weekend run might have nothing to do with sports performance, but caffeine is also one of the best researched performance aids available to endurance athletes.

For runners, the potential benefits are particularly interesting. Caffeine can improve endurance performance, increase alertness and reduce how hard exercise feels, potentially helping you maintain your pace when a run or race starts getting difficult. However, the amount you consume and when you take it can make a big difference.

You don't necessarily need a large dose or a special supplement either. Coffee can provide enough caffeine to influence performance, while caffeinated gels, drinks and chews give runners other options during longer events.

What Is Caffeine?

Caffeine is a natural stimulant found in coffee beans, tea leaves, cocoa and a number of other plants. It affects the central nervous system, particularly by blocking the action of adenosine, a chemical involved in promoting feelings of tiredness.

For runners, that can translate into increased alertness and a lower perception of effort during exercise. In simple terms, caffeine doesn't suddenly give you extra fitness, but a pace may feel slightly easier to sustain.

Caffeine is available from far more than coffee and tea. It is also added to some energy gels, sports drinks, chews, energy drinks and tablets, giving runners several ways to use it before or during exercise.

Does Caffeine Improve Running Performance?

There is strong evidence that caffeine can improve exercise performance, with aerobic endurance among the areas where its benefits have been most consistently demonstrated.

One of caffeine's most useful effects for runners is its influence on perceived exertion. If the same running intensity feels slightly easier, you may be able to maintain your effort more effectively before fatigue forces you to slow down.

Caffeine may also improve alertness, attention and vigilance. That can become particularly useful during longer events, when maintaining concentration becomes increasingly difficult as physical and mental fatigue develop.

The response isn't identical for everyone. Genetics, habitual caffeine consumption, individual sensitivity and the dose you take can all influence how caffeine affects both performance and side effects.

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How Much Caffeine Should Runners Take?

Sports nutrition research has consistently found performance benefits from caffeine at doses of around 3 to 6mg per kilogram of body weight. However, that doesn't mean every runner should immediately aim for that amount.

For a 60kg runner, 3mg/kg would equal 180mg of caffeine. For a 70kg runner it would be 210mg, while an 80kg runner would be looking at 240mg. The upper end of the commonly researched range would be considerably higher.

There is evidence that smaller doses can also be effective, and taking more doesn't necessarily produce a greater performance benefit. Higher doses are also more likely to cause unwanted effects including nervousness, nausea, headaches and sleep disruption.

If you're experimenting with caffeine for running, starting with a relatively modest amount during training is far more sensible than jumping straight to a high dose.

When Should You Take Caffeine Before Running?

Around 60 minutes before exercise is the most commonly researched timing for caffeine, particularly when it is consumed as coffee or in capsule form. However, the ideal timing depends partly on how you consume it.

Some forms of caffeine can be absorbed differently, so there isn't one perfect rule that applies to coffee, gels, chewing gum and every other caffeine product.

For most recreational runners using coffee before a race or important training session, having it roughly 45 to 60 minutes before running is a practical starting point. The most important thing is to test your routine during training and learn how your body responds.

Is Coffee Good Before Running?

Coffee can be a perfectly good source of caffeine before running and may provide a performance benefit. The difficulty is knowing exactly how much caffeine you're consuming.

Caffeine content can vary considerably depending on the type of coffee, serving size, beans and brewing method. Two coffees that look almost identical can therefore contain very different amounts of caffeine.

That isn't necessarily a problem for an everyday training run. If you're trying to follow a more precise caffeine strategy for a marathon or another target race, however, a product with a clearly stated caffeine content can make your intake easier to control.

Coffee can also stimulate the digestive system in some people. That may be useful before a morning run, but it can be less welcome when you're standing in a race start pen, which is another good reason to practise your routine beforehand.

How Much Caffeine Is In Coffee And Tea?

Caffeine content varies widely, so figures for individual drinks should always be treated as estimates. A typical cup of brewed coffee may contain roughly 80 to 100mg, but some coffees can contain considerably more.

Tea generally contains less caffeine than coffee, although its caffeine content also depends on the type of tea and how it is prepared. Energy drinks, cola, chocolate and sports nutrition products can all add to your total intake as well.

Even decaffeinated coffee usually contains a small amount of caffeine rather than being completely caffeine free.

If you're deliberately using caffeine for running performance, check the label of packaged products rather than assuming how much caffeine they contain.

Should You Use Caffeine During A Marathon?

Caffeine doesn't have to be consumed entirely before you start running. For longer endurance events such as marathons and ultramarathons, some runners use caffeinated gels, chews or drinks later in the race.

This can be particularly useful as fatigue develops, but caffeine should be considered alongside your complete fuelling strategy rather than as a replacement for carbohydrate. A caffeinated energy gel can provide both carbohydrate and caffeine, but it is still the carbohydrate that provides fuel.

Keep track of the caffeine from everything you consume. A pre-race coffee followed by several caffeinated gels can quickly add up, particularly if every gel in your race plan contains caffeine.

A useful approach can be to use a mixture of caffeinated and non-caffeinated products, depending on your individual strategy and tolerance.

Does Caffeine Dehydrate You When Running?

Caffeine is often described as dehydrating, which has led some runners to avoid coffee before races. For normal caffeine consumption, this concern is generally overstated.

Caffeine can have a mild diuretic effect, particularly in some circumstances, but research does not suggest that sensible caffeine use alongside exercise causes the kind of fluid imbalance that runners once feared.

That doesn't mean coffee should replace your normal hydration strategy. You still need to consider the length of your run, weather conditions, your individual sweat rate and access to fluids.

There is no need for most runners to avoid caffeine purely because they are worried that a pre-run coffee will automatically dehydrate them.

Can Caffeine Help Running Recovery?

Caffeine is much more established as a performance aid than as a recovery strategy. Some research has found that consuming caffeine alongside carbohydrate after prolonged exercise can increase muscle glycogen replenishment, but this has often involved relatively large caffeine doses and isn't a reason most runners need to deliberately take caffeine after training.

Your priorities after a demanding run should remain appropriate carbohydrate and protein intake, fluids and enough sleep. A normal cup of tea or coffee can comfortably fit into that routine if you enjoy it and tolerate caffeine well.

In fact, protecting your sleep may be considerably more important for recovery than trying to gain a potential recovery benefit from caffeine late in the day.

Does Caffeine Affect Sleep And Recovery?

This is one of the biggest reasons runners shouldn't think of caffeine simply as a performance enhancer. Caffeine can remain in the body for hours, and consuming it later in the day may interfere with sleep.

That matters because sleep is a fundamental part of recovery. A caffeinated gel that helps you through an evening training session isn't necessarily worthwhile if it then leaves you struggling to sleep.

Individual sensitivity varies considerably, so pay attention to how late you can consume caffeine without affecting your sleep rather than relying entirely on what works for somebody else.

Read about the importance of sleep for runners here.

How Much Caffeine Is Safe?

For healthy adults, caffeine intake of up to 400mg spread across the day is generally considered not to raise safety concerns. A single dose of up to 200mg is also considered safe for healthy adults under normal circumstances, including when consumed before intense exercise.

These are safety guidelines rather than performance targets. You don't need to consume 400mg simply because that amount is considered acceptable for most healthy adults.

Pregnant women are generally advised to keep total caffeine consumption to no more than 200mg per day. Anyone with a medical condition, taking medication that may interact with caffeine or who has concerns about increasing their caffeine intake should seek appropriate medical advice.

What Are The Side Effects Of Caffeine?

More caffeine doesn't mean better running. Large doses can cause jitteriness, headaches, nausea, increased heart rate, anxiety and digestive problems, while consuming caffeine too late can interfere with sleep.

Some runners are much more sensitive than others. One person may drink coffee before a race without noticing any negative effects, while another may experience stomach problems or feel uncomfortably overstimulated from a relatively small amount.

This individual variation is why caffeine needs to be practised in training in exactly the same way as your race-day breakfast, hydration and energy gels.

What About Caffeine Tablets?

Caffeine tablets provide a more precise dose than coffee, which can make them attractive to runners who want to know exactly how much caffeine they're consuming.

That precision can also be a disadvantage if it encourages you to take more than you need.

Tablets make it very easy to consume a relatively large amount of caffeine quickly, particularly if you forget to include coffee, tea, gels or other sources when calculating your total intake.

If you use caffeine tablets, follow the product instructions carefully and keep track of caffeine from every other source.

Should You Stop Drinking Coffee Before A Race?

Some runners deliberately reduce or stop their normal caffeine intake before an important race because they believe this will make caffeine more effective on race day.

Current evidence doesn't provide a strong reason for every habitual coffee drinker to go through caffeine withdrawal before racing. Suddenly stopping can also cause headaches, tiredness and irritability, which isn't necessarily what you want during race week.

If your normal coffee routine works well during training, there is usually little reason to make a dramatic change immediately before your race.

Read more about race day nutrition here.

Final Thoughts On Caffeine For Runners

Caffeine is one of the best supported performance aids available to runners. Research shows that it can improve endurance performance and alertness while reducing perceived effort, although the size of the benefit and the amount required vary between individuals.

You don't need huge amounts to potentially benefit. While 3 to 6mg per kilogram of body weight is the range most consistently associated with improved exercise performance in research, lower doses may also help and can reduce the risk of unwanted side effects.

For most runners, the best caffeine strategy is therefore a simple one. Find an amount you tolerate, test when and how you take it during training and consider the caffeine contained in coffee, gels, drinks and other products as part of your total intake.

Most importantly, don't sacrifice sleep or a well-practised fuelling strategy in pursuit of a caffeine boost. Used sensibly, caffeine can give your running a small but meaningful advantage. It doesn't replace the training that makes that performance possible.