It can be hard to head out the door for a run around the neighborhood or a tough workout at the gym. And once you’ve gotten going, it can be hard to push yourself to your limits and go all out. Understandably then, athletes and exercisers of all kinds frequently turn to caffeinated beverages, shots, and supplements to give them a little extra boost as they put themselves through the paces.
But does caffeine actually improve your physical performance? And if so, how do you consume it in order to maximize its benefits?
Today we’ll answer those questions, unpacking the ways caffeine can enhance your workouts, how much of it to consume, and when to throw it back.
How Caffeine Improves Athletic Performance
The connection between caffeine and improved athletic performance has been well-studied and well-vetted. In fact, the stimulant provides such an undeniable advantage that for a time, the World Anti-Doping Agency listed caffeine as a banned substance. That changed in 2004, but in 2017, talks began again about reinstituting the ban or at least setting a limit as to how much caffeine can be in an athlete’s system.
The decades of research that have been done on caffeine show that it can improve athletic performance in two main ways:
Increases Aerobic Endurance
Several studies have shown that caffeine can improve aerobic endurance. For example, one study found that athletes who consume caffeine before a run were able to cover more miles without tiring compared to a group that took a placebo.
Similar studies have shown that caffeine can reduce an athlete’s perception of effort during an aerobic event, allowing them to go longer without tiring.
Researchers believe this aerobic endurance benefit comes from the fact that caffeine blocks the A1 receptor in the brain, which helps control feelings of sleepiness and fatigue. With the A1 receptor blocked by a caffeine molecule, your brain doesn’t receive the signal that it’s feeling tired from a run.
Increases Anaerobic Performance
Research has shown that caffeine consumption before a strength training or sprinting workout can allow an athlete to lift more weight or sprint faster. According to science writer Alex Hutchinson, researchers believe “that caffeine directly affects how muscle fibers contract at a cellular level, making each fiber contract more strongly when it receives a signal from the nervous system.” The stronger the contraction, the more weight you can lift or the faster you can run.
Another anaerobic boosting effect of caffeine is that it can temporarily elevate testosterone levels, which can help increase strength or sprinting performance.
How Much Caffeine Do You Need to Consume for Athletic Improvement?
So caffeine can help improve your athletic performance. But how much do you have to consume to get the benefit?
A lot more than you’d think.
In a podcast interview I did with writer Murray Carpenter about his book Caffeinated, Murray highlighted research that shows that you need to consume about 6 mg of caffeine per kg of bodyweight; so if you weigh 200 lbs (90 kg), you’d need to consume about 540 mg of caffeine before your workout to get an athletic boost from the caffeine.
Other research has shown that you need to consume between 200-600 mg of caffeine to see an improvement in aerobic or anaerobic performance.
That’s a crapload of caffeine.
To put that in perspective, a single can of Red Bull has about 80 mg of caffeine; a cup of strong coffee has about 140 mg. Even if you were to consume caffeine at the low end of the recommended range for enhanced athletic performance, you’d need to throw back two and a half cans of Red Bull or two cups of strong coffee before your workout.
While those amounts can give you an athletic boost, they also come with the risk of gastrointestinal issues, jitters, or sleep disruption, all of which can hinder athletic performance.
You’ll have to experiment to see what dose works for you. Researchers have surmised that some of the boost athletes get from caffeine is simply from its placebo effect, and you can still garner this effect even if you’re taking the drug at low levels. While the placebo effect gets a bad rap, its impact can be quite real, and there’s something to be said for the way a pre-workout ritual — changing clothes, putting on some pump-up music, knocking back some caffeine — can make you feel ready to rock.
When Should You Consume Caffeine Before Your Workout?
Studies show that caffeine levels peak in the bloodstream around an hour after consumption (though this varies up or down based on how empty/full your stomach is, whether you took the caffeine in liquid or tablet form, and your personal physiology). So you’ll want to consume your caffeine based on when you want that peak to hit (keeping in mind that even after the peak, you’ll still have plenty of caffeine in your system; half of it will still be there 5-6 hours after you took it).
For example, if you’re going to be doing an hour-long workout, and you spend the first 20 minutes of it warming up/going at an easier pace before really kicking it into gear, then you might take your caffeine 45 minutes before your workout, so that it’s peaking around the time you start seriously pushing yourself.
Factoring in the Effect of Caffeine Tolerance
Caffeine can help you break new running records and smash PRs. So if you want to perform like a champion every day, you should consume caffeine before every single workout, right?
Well, maybe not.
Don’t forget: caffeine is a drug. And as with other drugs, your body and mind can develop a plateau-inducing tolerance, so that after a while the stimulant stops providing any performance enhancement. In order to get the same level of stimulating reaction as you did when you first started using caffeine, you have to consume progressively increasing amounts of it.
For that reason, many athletes cycle off caffeine every now and then so that their body doesn’t develop this tolerance. Carpenter highlights a few athletes in his book who only consume caffeine before a big competitive event. That way they know for sure they’ll get the maximum performance-enhancing boost from the drug; indeed, if you’ve used caffeine daily for a long time, you’ll have forgotten the kind of bang-pow rush the stimulant can produce in a fresh, “detoxified” system.
There are a few strategies you can use to ensure that you don’t develop a caffeine tolerance. One is to periodically cycle on and off it. For example, maybe one week a month you abstain from caffeine all together. Keep in mind that the body develops a dependence on caffeine, so that quitting cold turkey can bring on withdrawal symptoms. You may then want to taper off your consumption, taking a little less each day, before your week of complete abstention. So your cycle might look like:
- Week 1: Full caffeine
- Week 2: Full caffeine
- Week 3: Tapering off caffeine
- Week 4: No caffeine
You could also consume a low amount of caffeine before your regular workouts (like 80 mg to 100 mg) so you get a bit of a boost, but then crank up the levels to 200-600 mg when doing a big race or looking to hit a weightlifting PR.
You can also abstain from consuming caffeine during your training all together, saving it for when you really need it, like before a big athletic event. It’s both physically and psychologically advantageous to keep a sparingly-used “superpower” in your back pocket for special occasions. However, you should do a pre-competition practice run with the amount of caffeine you intend to consume during the event; remember that caffeine, especially if you’re not used to it, can cause gastrointestinal distress, and you don’t want to discover your susceptibility to that effect in the middle of a race.
The body’s reaction and tolerance to caffeine is a very individual thing, so when it comes to the specifics of dosage, timing, and cycling, experiment to find out what works best for you.