Caffeine used to be banned by the International Olympic Committee, and there’s still a limit to how much you can take.
This might seem a little nuts, but there is good research showing that caffeine can improve your performance in most sports.
In this podcast, you’ll learn…
- What caffeine does and doesn’t do to your performance.
- How much caffeine you should take for best results.
- Whether or not the effects of caffeine become less potent over time.
- When you should take caffeine to improve your performance.
Click the Player to Listen
Other Listening Options
Click here to download the mp3 | 18.5 MB | 20:09
“Good Day” by StereoResonance
Click here to leave a review on iTunes.
> Did you enjoy this podcast? [Click here to check out my book, *Flexible Dieting](https://evidencemag.com/flexible-dieting-book)*. Want an even more in-depth education on how to lose weight, build muscle, and get stronger and healthier? [Join Evidence Mag Elite](https://evidencemag.com/elite) and get member’s-only reports and interviews.
**Armi Legge:** Every athlete takes performance enhancing drugs, that is if you use the Merriam-Webster definition of a Drug:
“A medicine or other substance which has a physiological effect when ingested or otherwise introduced into the body.”
By that definition, glucose, water, and air are also performance enhancing drugs. And so is caffeine.
1,3,7-trimethylxanthine, AKA “caffeine” is the drug we’re going to talk about today.
Quick side note– remember that definition of “drug” the next time someone says junk food is a drug. So is broccoli.
Anyway, in this podcast, you’re going to learn what the research has shown caffeine does and doesn’t do for your physical performance, how much to take to get your desired effect, whether or not the effects of caffeine become less powerful over time, and when you should take caffeine for best results.
My name is Armi Legge and you are listening to Impruvism Radio, the podcast that gives you simple, science-based tips to improve your health, fitness, and productivity.
If you like what you hear in today’s show, go to impruvism.com, enter your email address in the box on the right side of the page and click the button below. After you do, you will get free updates from the Impruvism blog delivered to your email inbox when they’re published.
In the near future, you’ll also get a bunch of exclusive contact when you sign up for the email list. I’m going to be covering a bunch of other topics that I haven’t had a chance to write about on the blog yet, mostly on psychological research.
You’re going to learn about how different mannerisms and facial expressions affect the people you interact with, what science has shown are the best predictors long-term relationship success, how different mental cues can affect your athletic performance, the different ways you can increase your willpower, and other interesting, scientific tidbits that you can use to improve your health, fitness, and productivity.
You will receive this info as a series of emails after you sign up. I will be using this newsletter as a testing ground for new ideas on the blog, so you will be getting early access to a lot of information that most people won’t get.
If you’re already signed up for email updates, you will get all of this information sent to you automatically.
One of the topics you’ll also learn more about is supplementation. Personally, I don’t find supplements nearly as interesting as other topics like macronutrition, strength training, eating disorders, relationships, and the like because most most supplements don’t work. However, I do get excited when research uncovers a supplement that does seem to work, especially if it’s tasty like caffeinated coffee.
In today’s podcast, we’ll look at how caffeine affects the three main types of exercise.
1) Strength training, e.g. lifting weights
2) Sprinting and mixed sports like soccer, lacrosse, football, and basketball
3) Endurance sports like swimming, cycling, and running
In general, caffeine does seem to improve your strength performance depending on the type of strength training you’re doing. If you are doing heavy singles, doubles, or triples like normal powerlifting style workouts, which is where you lift as much weight as you can from 1 – 4 reps, there is not much evidence caffeine will help. When people perform really high intensity lifts like this, they usually don’t perform any better after caffeine than they do after taking a placebo.
However, other research has shown that caffeine can improve your strength in moderate to high rep ranges, like 6 – 12 reps or even up to around 20 – 25 reps. When people perform as many reps as possible, to the point they can’t do another, those who take caffeine will generally knock out around 1 – 3 reps more, or around 10% – 12% more volume within that set.
Caffeine also tends to reduce sensations of pain and relative perceived exertion, so when people are allowed to select how much weight they lift and how many reps they do, they usually end up doing more voluntarily.
A review published in 2010 in the Journal of Strength and Conditioning Research summarized the literature on caffeine for enhancing strength performance. They found 29 studies that measured caffeine’s effect on short-term, high-intensity efforts like weightlifting.
11 out of 17 studies found significant improvements in team sports and power-based sports. In general, athletes who were not used to taking caffeine got a larger boost than those who were regular users. 6 out of 11 of these studies also found significant improvements in strength training performance.
Overall, seems that caffeine doesn’t do much for your strength training in the 1 – 5 rep range but it can improve your muscular endurance in sets that are above around 6 reps. It doesn’t always increase how much weight you can lift in these rep ranges, but you generally can do more reps with the same weight or more total sets if you take caffeine.
Other data indicates that sleep deprived athletes can increase their reps to failure at 85% of their 1-repetition maximum by taking caffeine. In fact, taking caffeine brought their performance back up to that of people who weren’t sleep deprived. Of course, those who got enough sleep and took caffeine did the best. If you listened to the podcast I did with Dan Pardi on how sleep affects your fat loss, then that probably won’t come as news to you.
Now let’s look at how caffeine affects your sprinting performance and whether or not football players should take a performance enhancing drugs like caffeine in addition to the ones they’re probably already taking.
In early studies, researchers generally didn’t find any significant improvements in sprinting performance after people took caffeine. However, they often used untrained subjects and kind of odd study protocols that aren’t really relevant to how most people compete and train.
Another review published in 2009 in the Journal of Sports Medicine find that “caffeine seems highly ergogenic [or performance enhancing] for endurance exercise ranging in duration from 60 to 180 seconds.” That’s pretty typical for a lot of mixed sports, especially those like soccer or hockey where you don’t get much of a break.
Luckily, other studies have also found that, in more realistic tests for sports like hockey, rugby, and soccer, people do perform better for even short, 4 – 6 second efforts after taking caffeine. However, other tests like their 1-rep max and the peak isokinetic torque, which is basically how hard they can push on something, are not improved.
One of the most important skills for a mixed sport athlete is repeated sprint ability. You have to be able to sprint as hard as you can and recover between the efforts quickly. In fact, some data has shown that athletes like soccer players can run over 10km or 6mi in a single game.
In these kinds of studies, caffeine tends to have somewhat mixed results. At least one study found a 1.4% reduction in the fastest sprinting speed of physically active males. However, most of the time studies have shown that people perform better during these kinds of tests after taking caffeine.
Other studies have also shown that people tend to sprint faster and have a higher average sprint speed within each effort and end up doing more total volume in repeated sprint tests when they take caffeine.
Studies also indicate that higher doses of caffeine are usually better for improving your repeated sprint ability.
Overall, caffeine seems like a safe bet for both strength and sprinting sports. Perhaps a little ironically, caffeine seems to be best for improving endurance performance. I say “ironically” since it’s hard to talk about endurance sports without talking about doping of some kind.
Many studies on endurance performance use what’s called a “time to exhaustion” test. What they usually do is figure out an athlete’s VO2 max, which is the maximum amount of oxygen they can consume over roughly a 3 – 8 minute period. The researchers measure how fast the athlete was moving or how much power they were producing at that intensity and use that number to determine how hard they should work for the rest of the study.
In studies testing caffeine, the athletes are usually told to work at a pace around 80% of their VO2 max for as long as they can. When their pace drops a certain percentage, they stop and the researchers measure their times.
In these kinds of studies, caffeine generally improves performance by about 20% – 40%, which is huge. However, there are almost no endurance races that are in this format and there’s often a ton of variability in how long people are able to perform in these tests, which makes them pretty misleading.
However, keep in mind that this can still help people train longer and harder, which could improve their race performance over time. In later time trial tests, where athletes are told to work for a certain duration or distance, caffeine still significantly improves performance.
A 2009 review found 21 studies looking at how caffeine affected endurance time trial performance only. On average, the improvement was around 3.2%. However, it ranged from -0.3% – 17.3% and the researchers thought this was because of “factors including ingestion timing, ingestion mode or vehicle, and subject habituation.” Basically, these differences were probably because the athletes consumed caffeine at different times before exercise, consumed it in a different form, and may have been more or less used to taking caffeine on a regular basis.
These studies have also generally found that athletes who don’t take caffeine as often usually get a larger boost in performance, at least in time to exhaustion tests. Athletes who don’t take caffeine regularly can generally last longer without getting fatigued and usually also get a much larger boost of performance throughout the day than people who are regular caffeine users.
So across the board caffeine tends to improve performance in strength sports, mixed sports, and endurance sports. Pretty sweet.
There are several reasons researchers think this is the case.
Caffeine does mobilize more fatty acids during exercise, but there is not much evidence this is what improves performance. It also probably wouldn’t make any difference in strength performance.
Others have suggested that caffeine works by increasing the response of your muscles to catecholamines, which are stimulatory hormones. That is true. Caffeine does do that. But the rise in catecholamines during exercise doesn’t seem to be very well correlated with the amount of caffeine you take.
There is also some evidence caffeine could increase the amount of caffeine mobilization in your muscles, which could theoretically increase your power output. But once again, frankly, none of these theories are very well supported.
Most evidence indicates that caffeine works by stimulating your central nervous system. It seems to decrease your perception of pain and relative perceived exertion during exercise. This is probably why it increases the total amount of volume and intensity people use in exercise voluntarily and why people tend to rate exercise at the same intensity as being easier when they take caffeine.
Not all studies have found this reduction in perceived effort improves performance, but these results can generally be explained by the study design.
Some recent evidence indicates that you might need to just taste caffeine to get the benefits. Researchers found that swishing your mouth with caffeine during recovery intervals during 5 – 6 second sprints increased peak and average power during the first few efforts. Performance tended to drop off afterward, but that’s expected with these kinds of workouts.
Basically, caffeine seems to stimulate certain receptors in your mouth that tell your brain it can work harder for longer without getting tired. Other studies have found that carbohydrates can do the same thing.
Caffeine seems to work, even if we don’t have a perfect idea of why it works. Now let’s talk about how to use it.
In general, studies have found that you can improve your performance by taking around 3mg – 6mg of caffeine per 1kg of total body weight.
Strength athletes, or people doing multiple sprints generally need to take higher doses to get a significant boost.
When it comes to endurance performance, studies indicate that athletes can often get the same benefit from lower doses as they can get from higher doses if they’re not habitual caffeine users. If you do regularly take caffeine, you usually have to take slightly more to enhance your endurance performance because your body gets used to the effects.
Some studies have also found this to be true for strength athletes but others have not.
It’s hard to say exactly how much caffeine to take because your ability to metabolize caffeine is largely determined by your genetics, your health, and what kind of other medications you’re taking. Some people get a little queasy after a small dose while others, like me, can drink ridiculous amounts of coffee and barely notice.
There’s also a good bit of data showing that people who experience the most effects, both positive and negative, tend to expect these effects ahead of time. Basically, some people tend to get a bigger placebo or nocebo effect than others. This variability seems to be even more common in studies on strength athletes, where there are usually a larger number of responders and non-responders.
In most cases, you’re safe starting at around 3mg of caffeine per 1kg of total body weight and working your way up to around 6mg of caffeine per 1kg. Larger doses than that don’t seem to have much of an additional effect in terms of athletic performance.
Most studies have given caffeine to people about one hour before exercise. Caffeine usually takes around 45 minutes to get into your blood stream, so a one hour window is usually enough to make sure you’re high before you work out.
About half of the caffeine you consume leaves your system after around 5 to 6 hours, which makes the effects much less noticeable. If you take smaller doses of caffeine, such as 2.5mg – 4mg per 1kg, then you can usually take it for about 3 – 4 days straight while still getting the full benefit.
Interestingly, some of the effects of caffeine don’t go away if you keep using it. Caffeine usually increases your wakefulness and mood even if you’re used to it. However, you generally don’t have as much as a boost in performance and concentration over time if you keep taking the same dose.
Other studies have shown that caffeine can improve athletes’ concentration even more when they’re sleep deprived or fatigued.
In general, researchers recommend not using caffeine at least 5 – 7 days before you want it to be most effective, like before a fitness competition or race.
If we assume that you metabolize caffeine as most do, then you’d have to consume around 20mg – 40mg of caffeine per 1kg of body weight to reach dangerous levels. That’s about 5x – 10x what most people consume in a sitting. For a 70kg or 154 pound person, that would be 1,400mg – 2,800mg of caffeine, or around 29 eight-ounce cups of regular coffee.
There’s also some evidence that caffeine may be harmful to fetuses while you’re pregnant. Since everybody knows that coffee is the best way to consume caffeine, I’ve included a cool article in the show notes of this podcast from thrillist.com that lists how much caffeine is in different kinds of coffee.
Starbucks tends to have the most with almost twice as much than other brands like McDonalds. There’s also a kind of coffee called “Death Wish” that has around 430mg of caffeine per 8oz, which would be almost exactly 6mg per 1kg for a 154 pound person.
Caffeine is cool stuff. It improves your performance in strength, endurance, and mixed sports. It’s also relatively cheap and comes in a delicious delivery vehicle: coffee.
Start by taking around 3mg – 6mg per 1kg an hour before you work out and see how you feel. For an average sized person at around 150 pounds, that would be about two cups of coffee or more.
It’s Halloween, which means people all over the United States are begging for candy from strangers in weird costumes. More importantly, it means you’re probably going to stay up watching a horror movie or eating candy, two activities you can easily do while leaving a quick review for this podcast on iTunes. To do so, navigate to impruvism.com/itunes and leave your thoughts as a ranking or review.
Speaking of candy, in one of the next podcasts, we’ll take a close look at whether or not you can actually become addicted to junk food and/or sugar.
‘Til next time, enjoy your candy.
1. Astorino TA, Roberson DW. Efficacy of acute caffeine ingestion for short-term high-intensity exercise performance: a systematic review. J Strength Cond Res. 2010;24(1):257–265. doi:10.1519/JSC.0b013e3181c1f88a.
2. Ganio MS, Klau JF, Casa DJ, Armstrong LE, Maresh CM. Effect of caffeine on sport-specific endurance performance: a systematic review. J Strength Cond Res. 2009;23(1):315–324. doi:10.1519/JSC.0b013e31818b979a.
3. Davis JK, Green JM. Caffeine and anaerobic performance: ergogenic value and mechanisms of action. Sports Med. 2009;39(10):813–832. doi:10.2165/11317770-000000000-00000.
4. Beaven CM, Maulder P, Pooley A, Kilduff L, Cook C. Effects of caffeine and carbohydrate mouth rinses on repeated sprint performance. Appl Physiol Nutr Metab. 2013;38(6):633–637. doi:doi: 10.1139/apnm-2012-0333.
5. Astorino TA, Rohmann RL, Firth K. Effect of caffeine ingestion on one-repetition maximum muscular strength. Eur J Appl Physiol. 2008;102(2):127–132. doi:10.1007/s00421-007-0557-x.
6. Cook C, Beaven CM, Kilduff LP, Drawer S. Acute caffeine ingestion’s increase of voluntarily chosen resistance-training load after limited sleep. Int J Sport Nutr Exerc Metab. 2012;22(3):157–164.
7. Bell DG, McLellan TM. Exercise endurance 1, 3, and 6 h after caffeine ingestion in caffeine users and nonusers. J Appl Physiol. 2002;93(4):1227–1234. doi:10.1152/japplphysiol.00187.2002.
8. Graham TE, Spriet LL. Metabolic, catecholamine, and exercise performance responses to various doses of caffeine. J Appl Physiol. 1995;78(3):867–874.
9. Backhouse SH, Biddle SJH, Bishop NC, Williams C. Caffeine ingestion, affect and perceived exertion during prolonged cycling. Appetite. 2011;57(1):247–252. doi:10.1016/j.appet.2011.05.304.
10. Hadjicharalambous M, Georgiades E, Kilduff LP, Turner AP, Tsofliou F, Pitsiladis YP. Influence of caffeine on perception of effort, metabolism and exercise performance following a high-fat meal. J Sports Sci. 2006;24(8):875–887. doi:10.1080/02640410500249399.
11. Schneiker KT, Bishop D, Dawson B, Hackett LP. Effects of caffeine on prolonged intermittent-sprint ability in team-sport athletes. Med Sci Sports Exerc. 2006;38(3):578–585.
12. Bishop D. Dietary supplements and team-sport performance. Sports Med. 2010;40(12):995–1017. doi:10.2165/11536870-000000000-00000.
13. Carr A, Dawson B, Schneiker K, Goodman C, Lay B. Effect of caffeine supplementation on repeated sprint running performance. J Sports Med Phys Fitness. 2008;48(4):472–478.
14. Sokmen B, Armstrong LE, Kraemer WJ, et al. Caffeine use in sports: considerations for the athlete. J Strength Cond Res. 2008;22(3):978–986. doi:10.1519/JSC.0b013e3181660cec.
15. Glaister M, Howatson G, Abraham CS, et al. Caffeine supplementation and multiple sprint running performance. Med Sci Sports Exerc. 2008;40(10):1835–1840.
16. Bellar D, Kamimori GH, Glickman EL. The effects of low-dose caffeine on perceived pain during a grip to exhaustion task. J Strength Cond Res. 2011;25(5):1225–1228.
17. Duncan MJ, Oxford SW. Acute caffeine ingestion enhances performance and dampens muscle pain following resistance exercise to failure. J Sports Med Phys Fitness. 2012;52(3):280–285.
18. Duncan MJ, Stanley M, Parkhouse N, Cook K, Smith M. Acute caffeine ingestion enhances strength performance and reduces perceived exertion and muscle pain perception during resistance exercise. European Journal of Sport Science. 2013;13(4):392–399. doi:10.1080/17461391.2011.635811.
19. Astorino TA, Martin BJ, Schachtsiek L, Wong K, Ng K. Minimal effect of acute caffeine ingestion on intense resistance training performance. J Strength Cond Res. 2011;25(6):1752–1758. doi:10.1519/JSC.0b013e3181ddf6db.