Can You Build a Tolerance to Caffeine? And What Can You Do About It?

Caffeine is one of the most widely used performance enhancing substances in the world. It is also one of the few sports supplements with a large amount of research showing legitimate benefits for alertness, perceived effort, endurance performance, and several other types of exercise.

The problem is that caffeine often seems to work differently after you've been using it for a while. Someone who rarely consumes caffeine might feel a very noticeable effect from 150 or 200 mg. After drinking coffee every morning and taking a caffeinated pre-workout several times per week, that same 200 mg might barely be noticeable.

The natural response is usually to increase the dose. Two hundred milligrams becomes 300 mg. Then 300 becomes 400 mg. Eventually, some people reach the point where caffeine isn't making them feel particularly energized anymore. They're taking it because they feel tired without it.

So, can you actually develop a tolerance to caffeine?

Yes. Your body can adapt to regular caffeine consumption, and some of caffeine's effects can become less noticeable over time. What is less clear is whether caffeine tolerance completely eliminates its ability to improve exercise performance. The research suggests that the answer is probably no.

Understanding the difference between those two things can help you use caffeine much more effectively.

TLDR: Yes, Caffeine Tolerance Is Real

Regular caffeine consumption can reduce some of the effects you initially notice from caffeine, but that doesn't necessarily mean caffeine has completely stopped working.

• Caffeine works primarily by blocking adenosine receptors in the brain, which reduces some of the signals associated with sleepiness and fatigue.
• Repeated caffeine exposure causes the body to adapt, which can make the same dose feel less noticeable over time.
• Feeling less stimulated doesn't necessarily mean caffeine has stopped improving performance.
• Research on habitual caffeine use and exercise performance is mixed. Some studies show reduced benefits with regular use, while others still find meaningful performance improvements.
• Caffeine commonly improves exercise performance around 3 to 6 mg/kg, although benefits can occur at lower doses and more isn't necessarily better.
• Continually increasing your caffeine dose can increase anxiety, jitters, gastrointestinal problems, and sleep disruption without producing better performance.
• Using caffeine selectively for important workouts and competitions may make more sense than automatically taking it before every workout.
• Temporarily reducing caffeine may restore some sensitivity, but there is no scientifically established perfect caffeine reset period.
• Abruptly stopping caffeine can cause withdrawal symptoms that usually begin within about 12 to 24 hours and may last several days.
• If caffeine intake keeps increasing because you're constantly tired, it may be worth addressing sleep, nutrition, training load, and recovery rather than simply adding more caffeine.

My general approach is simple: use the lowest dose that produces the result you want, and don't take caffeine automatically just because you're about to exercise.

How Does Caffeine Actually Work?

To understand caffeine tolerance, it helps to first understand a chemical called adenosine.

Your brain is constantly using energy while you're awake. Over the course of the day, adenosine signaling increases and contributes to what researchers often describe as sleep pressure. As you've been awake longer, adenosine helps communicate that increasing need for rest.

Caffeine has a molecular structure that allows it to bind to adenosine receptors, particularly the A1 and A2A receptors. Instead of activating those receptors the way adenosine normally would, caffeine blocks them. This reduces some of adenosine's effects and helps explain why caffeine can increase alertness and reduce feelings of fatigue.

This also helps explain why caffeine can improve exercise performance. Caffeine can influence perceived exertion, alertness, motor function, and the ability to maintain effort during exercise. The International Society of Sports Nutrition's position stand concluded that caffeine can improve several forms of exercise performance, including aerobic endurance, muscular endurance, movement velocity, sprinting, and jumping, although individual responses vary considerably. ISSN position stand on caffeine and exercise performance

Caffeine Doesn't Actually Give You Energy

We often say caffeine "gives us energy," but physiologically that's not really what is happening.

Caffeine itself isn't refilling your muscle glycogen or supplying meaningful calories for your muscles to use. A cup of black coffee can make you feel much more energetic without providing the fuel needed to produce that energy.

What caffeine primarily changes is how your brain and nervous system respond to fatigue and effort.

That's an important distinction for athletes. During a hard workout, caffeine may make a given pace or workload feel slightly easier. That can allow you to maintain your effort longer or produce a little more work before fatigue forces you to slow down.

In other words, caffeine isn't necessarily giving the engine more fuel. It's changing some of the signals that tell you how hard the engine is working.

So How Do You Develop a Tolerance to Caffeine?

The human body is extremely good at adapting to repeated changes in its environment. If you repeatedly alter a biological system, the body often makes adjustments in an attempt to maintain balance.

Regular caffeine consumption repeatedly interferes with normal adenosine signaling. Over time, the nervous system can adapt to that repeated exposure. Experimental research has found changes in the adenosine system following chronic caffeine use, including changes in receptor availability and sensitivity. Review of habitual caffeine use and tolerance in athletes

The practical result is something most regular coffee drinkers recognize immediately. A dose that once produced a strong feeling of alertness may eventually feel much less impressive.

Imagine someone who rarely consumes caffeine drinking 200 mg before a workout. They might feel extremely alert, energized, and perhaps even slightly jittery. If that person begins consuming 200 mg every morning for several months, the same dose may eventually do little more than make them feel normal.

That's caffeine tolerance.

Feeling Caffeine and Benefiting From Caffeine Aren't the Same Thing

This is probably the most important distinction to make.

Most people judge whether caffeine is working by how stimulated they feel. If their heart isn't beating faster and they don't get the same noticeable buzz they once did, they assume caffeine has stopped working.

Exercise performance isn't that simple.

You can develop tolerance to some of caffeine's noticeable effects while potentially retaining at least some of its ability to improve performance. That's one reason research examining habitual caffeine use has produced mixed results.

The absence of a strong stimulant feeling therefore doesn't necessarily mean caffeine is doing nothing. How caffeine feels and what caffeine does aren't always the same thing.

Does Caffeine Tolerance Reduce Its Performance Benefits?

There is evidence that it can.

One interesting study recruited people who normally consumed less than 75 mg of caffeine per day. The participants then consumed caffeine daily for several weeks, eventually reaching 3 mg/kg per day. Researchers found that the acute performance benefit from caffeine became smaller as regular caffeine exposure continued. Beaumont et al. study on caffeine tolerance and performance

That provides pretty good evidence that repeated caffeine exposure can reduce at least some of caffeine's performance enhancing effects.

However, other research complicates the picture. Studies involving habitual caffeine users have still found improvements in exercise performance after an acute caffeine dose, and the ISSN position stand concluded that habitual caffeine intake does not necessarily eliminate caffeine's ergogenic effects. ISSN review of habitual caffeine use and performance

More recent research has continued to suggest that habitual caffeine intake can reduce some responses while caffeine still retains the ability to improve performance. Recent research on habitual caffeine use and exercise performance

So I wouldn't tell someone who drinks coffee every morning that caffeine no longer works for them.

A better interpretation is that regular caffeine use may reduce some of caffeine's effects without necessarily eliminating its performance benefits altogether.

How Much Caffeine Do You Actually Need?

This is where caffeine use often starts getting unnecessarily aggressive.

Research has traditionally found reliable performance benefits around 3 to 6 mg of caffeine per kilogram of body weight. However, benefits have also been reported at lower doses, and there is little reason to assume everyone needs to start near the top of that range.

For a 180 pound athlete, or approximately 82 kg, 3 mg/kg would equal about 246 mg of caffeine, while 6 mg/kg would equal approximately 492 mg.

That doesn't mean a 180 pound athlete should immediately take 500 mg before training.

The ISSN notes that very high doses, such as approximately 9 mg/kg, aren't necessary for improving performance and substantially increase the likelihood of side effects. ISSN caffeine dosing recommendations

If 150 or 200 mg noticeably improves your workout, there isn't much reason to use 400 mg just because a calculator says you technically fall within a research supported range.

The goal should be finding the lowest effective dose, not the highest dose you can tolerate.

More Caffeine Doesn't Always Mean Better Performance

This is where tolerance can create problems.

Suppose 150 mg used to work well. Eventually it doesn't feel as noticeable, so you increase the dose to 250 mg. Several months later, that doesn't feel particularly strong either, so you move to 350 or 400 mg.

Increasing the dose may temporarily make the stimulant effect more noticeable, but it also increases the chance of anxiety, jitters, gastrointestinal discomfort, headaches, elevated heart rate, and sleep disruption.

The sleep issue is particularly important because using caffeine to deal with fatigue can sometimes create more fatigue.

Imagine taking a large pre-workout dose at 4 p.m. because you're tired. The caffeine gets you through your workout, but you don't sleep particularly well that night. You wake up tired the next morning and drink extra coffee. You're tired again that afternoon, so you take another pre-workout.

Now caffeine is being used to compensate for fatigue that caffeine may be helping create.

That can become a very easy cycle to fall into.

Caffeine Can Stay in Your System Longer Than You Think

Caffeine has an average half-life of roughly four to six hours in healthy adults, although there is substantial individual variation.

If you consume 300 mg of caffeine at 4 p.m. and your caffeine half-life is around five hours, roughly half of that caffeine could still be present in your body around 9 p.m. Several hours later, a meaningful amount can still remain.

That doesn't mean everyone who drinks coffee in the afternoon will have terrible sleep. Genetics, habitual caffeine use, medications, pregnancy, smoking status, and other factors can alter caffeine metabolism.

But feeling capable of falling asleep doesn't necessarily mean caffeine isn't affecting sleep quality.

A controlled study published in the Journal of Clinical Sleep Medicine found that 400 mg of caffeine consumed even six hours before bedtime significantly disrupted sleep. Study of caffeine consumed 0, 3, or 6 hours before bedtime

For athletes, that's worth thinking about because sleep is one of the most important recovery tools available.

Before Increasing Caffeine, Ask Why You're Tired

This is something I think gets overlooked in sports nutrition.

If you suddenly need twice as much caffeine to get through training, caffeine tolerance might be part of the problem.

But it might not be the whole problem.

Maybe you've been training hard for six weeks without reducing your workload. Maybe you're sleeping six hours per night. Maybe you're not eating enough carbohydrates to support your training. Maybe you're chronically dehydrated. Maybe you're simply accumulating training fatigue.

Caffeine can reduce the feeling of fatigue without correcting the reason you're fatigued.

That's useful during a race.

It's less useful if you're using it every day to hide a recovery problem.

Sometimes the solution to needing more caffeine isn't more caffeine. It's more recovery.

You Probably Don't Need Caffeine Before Every Workout

This is one of the easiest ways to keep caffeine useful without completely eliminating it.

Suppose you're doing an easy 45 minute Zone 2 run. There probably isn't a compelling reason to take 300 mg of caffeine beforehand.

The same could apply to an easy recovery ride, light strength session, technique workout, or other low priority training day.

Now compare that with a hard interval session, long endurance workout, important strength session, race, or competition. In those situations, caffeine may provide a meaningful performance advantage.

Using caffeine selectively has two potential advantages. You reduce your total caffeine exposure, and you preserve caffeine as something you use when the performance benefit actually matters.

Think of caffeine as a performance tool rather than a required part of exercising.

Should You Take a Break From Caffeine?

This is where people usually start talking about a "caffeine reset."

Search online and you'll find people recommending everything from 48 hours to a full month without caffeine.

The problem is that there isn't a scientifically established caffeine reset duration that applies to everyone.

Research does suggest that at least some caffeine habituation can be reversed after caffeine intake is reduced or eliminated. One older study involving women consuming more than 600 mg of caffeine per day found greater physiological responses to caffeine after four days of abstinence compared with maintaining their normal high caffeine intake. Study of caffeine abstinence and physiological response

Recent research has also suggested that temporary caffeine withdrawal may restore some of the ergogenic effect lost with habitual caffeine consumption. Recent study on caffeine habituation and withdrawal

That doesn't make four days a magical reset period. Someone consuming 100 mg per day and someone consuming 700 mg per day aren't starting from the same place.

Genetics, habitual intake, length of use, and individual sensitivity probably all influence the response.

You Don't Necessarily Have to Quit Completely

If you're consuming a lot of caffeine every day, reducing your intake may be enough to improve the situation.

Someone consuming 500 mg per day could remove an afternoon energy drink, stop using caffeinated pre-workout on easy training days, switch one cup of coffee to decaf, or reserve larger caffeine doses for key workouts.

This may be much easier than completely eliminating caffeine, especially if you genuinely enjoy your morning coffee.

Another strategy is reducing caffeine during easier training periods or deload weeks. Training stress is already lower, so there's less reason to rely on caffeine for performance. Then caffeine can be reintroduced more strategically when harder training resumes.

I prefer that approach to creating an unnecessarily complicated caffeine cycling schedule.

Be Careful With Caffeine Withdrawal

If you're a regular caffeine user, suddenly going from a high intake to zero can be unpleasant.

A major review of caffeine withdrawal found that common symptoms include headache, fatigue, sleepiness, difficulty concentrating, reduced alertness, and changes in mood. Symptoms generally begin around 12 to 24 hours after stopping caffeine, become strongest roughly 20 to 51 hours later, and can last approximately 2 to 9 days. Review of caffeine withdrawal symptoms and duration

Withdrawal has also been reported in people consuming relatively modest amounts of caffeine.

This matters if you're an athlete considering stopping caffeine before a competition. Going from several hundred milligrams per day to zero two days before an important race could leave you with a headache, fatigue, poor concentration, and a terrible mood right when you're supposed to be tapering and feeling good.

If you consume a lot of caffeine, gradually reducing the dose may be more comfortable than stopping abruptly.

Do You Need to Cycle Caffeine?

Probably not in the rigid way supplement culture sometimes recommends.

There isn't good evidence supporting a universal schedule such as three weeks on caffeine followed by one week off.

I'd rather manage caffeine based on training needs.

During easier training periods, use less.

During recovery sessions, consider skipping it.

During hard workouts and competitions, use it when there's a clear reason.

If you're consuming so much that your normal dose no longer seems useful, temporarily reduce your intake.

This approach naturally creates periods of higher and lower caffeine exposure without turning your morning coffee into a complicated pharmaceutical protocol.

What If Your Pre-Workout Doesn't Feel Strong Anymore?

Before doubling the serving, calculate how much caffeine you're actually consuming each day.

That includes coffee, pre-workout, energy drinks, tea, soda, caffeinated gels, chews, gum, and anything else containing caffeine.

Someone might think they're taking "only 250 mg" because that's what's in their pre-workout while forgetting about the 200 mg from morning coffee and another 150 mg from an afternoon energy drink.

Then look at the rest of your recovery.

If you're sleeping poorly, eating too little, under-consuming carbohydrates, dehydrated, or carrying a lot of accumulated training fatigue, another 100 mg of caffeine isn't fixing the real problem.

This is especially important because caffeine can make you temporarily feel capable of doing more work than your recovery habits can support.

Caffeine can hide fatigue. It doesn't erase it.

Do You Have to Feel Caffeine for It to Work?

No, and I think this is where a lot of people get into trouble with pre-workouts.

A good caffeine dose doesn't need to make your heart pound or make you feel like you could run through a wall.

The actual performance benefit might be much less dramatic. A pace that normally feels like an eight out of ten might feel like a seven. You may be able to maintain your pace slightly longer. Your last few intervals might be better. You may be more alert during a long training session.

Those aren't flashy effects, but they're exactly the type of improvements we're looking for from an ergogenic aid.

Don't judge caffeine entirely by how stimulated it makes you feel.

What I Would Actually Do About Caffeine Tolerance

If I wanted caffeine to remain useful for training and competition, I wouldn't make the strategy very complicated.

First, I would use the lowest dose that reliably produces the desired effect. If 150 mg works, I wouldn't use 300 mg simply because more sounds better.

Second, I wouldn't automatically take caffeine before every workout. I'd save supplemental caffeine for sessions where alertness or performance actually matters and skip it for many easier workouts.

Third, I'd pay attention to my total daily intake rather than treating coffee, energy drinks, and pre-workout as separate things.

I'd also be careful with afternoon and evening caffeine because protecting sleep is more important for long term performance than squeezing a little more stimulation out of one workout.

If caffeine stopped feeling effective, I'd reduce my intake before increasing it. Depending on my normal consumption, that might mean several days of lower intake, switching some drinks to decaf, eliminating unnecessary supplemental caffeine, or temporarily abstaining altogether.

If I were consuming a high amount every day, I'd probably taper down rather than stopping abruptly.

Most importantly, if I needed caffeine just to feel normal, I'd take that as a sign that my relationship with caffeine probably needed to change.

The Bottom Line

Yes, you can build a tolerance to caffeine.

Your nervous system adapts to repeated caffeine exposure, and the noticeable effects of a dose can become smaller over time. That explains why someone who rarely drinks caffeine may feel a strong response from 150 mg while a habitual user can consume 300 mg and barely notice it.

What happens to caffeine's performance benefits is less straightforward. Some research shows that habitual caffeine consumption reduces its ergogenic effect, while other studies show that regular caffeine users still improve performance after taking caffeine. The best interpretation right now is probably that tolerance can reduce some of caffeine's effects without necessarily eliminating its ability to improve exercise performance.

That means continually increasing the dose isn't necessarily the best solution.

Instead, use caffeine strategically. Find the lowest dose that works, skip it for some easier workouts, protect your sleep, and pay attention to caffeine coming from every source throughout the day. If your intake has gradually climbed and caffeine doesn't seem to do much anymore, reducing your consumption for a period of time may help restore some sensitivity.

And if you're constantly using caffeine because you're exhausted, don't automatically assume you have a caffeine problem.

You may have a sleep, nutrition, recovery, or training load problem that caffeine is temporarily covering up.

Caffeine is one of the most effective performance supplements we have. There's no reason to be afraid of it, but there also isn't much benefit in taking more and more just to recreate the buzz you felt when you first started using it.

Use it when it serves a purpose, and you'll probably get more out of it.

About the Author

Matt Mosman, MS, CISSN, CSCS, is the founder and Chief Science Officer of Simply Good Supplements. With a background in exercise science, sports nutrition, and strength and conditioning, Matt focuses on turning research into practical advice that athletes, parents, and everyday active people can actually use.

References:

1. Guest NS, VanDusseldorp TA, Nelson MT, et al. International Society of Sports Nutrition position stand: caffeine and exercise performance. Journal of the International Society of Sports Nutrition. 2021;18:1. This position stand reviews caffeine dosing, performance effects, habitual use, genetics, and individual variability. Full article
2. Beaumont R, Cordery P, Funnell M, Mears S, James L, Watson P. Chronic ingestion of a low dose of caffeine induces tolerance to the performance benefits of caffeine. Journal of Sports Sciences. 2017;35(19):1920–1927. The researchers found that several weeks of daily caffeine consumption reduced the acute performance benefit of caffeine in people who previously consumed relatively little caffeine. PubMed
3. Pickering C, Kiely J. What Should We Do About Habitual Caffeine Use in Athletes? Sports Medicine. 2019;49:833–842. This review discusses caffeine habituation, performance, withdrawal, and whether athletes should alter habitual caffeine consumption before competition. Full article
4. Juliano LM, Griffiths RR. A critical review of caffeine withdrawal: empirical validation of symptoms and signs, incidence, severity, and associated features. Psychopharmacology. 2004;176:1–29. The review describes the symptoms, timing, and duration of caffeine withdrawal. PubMed
5. Drake C, Roehrs T, Shambroom J, Roth T. Caffeine Effects on Sleep Taken 0, 3, or 6 Hours before Going to Bed. Journal of Clinical Sleep Medicine. 2013;9(11):1195–1200. The study found significant sleep disruption when 400 mg of caffeine was consumed even six hours before bedtime. PubMed