20 Feb

Dear Mark: Should I Consume Caffeine Before My Workout?

coffeeIn today’s edition of Dear Mark, I cover a topic near and dear to many of your hearts: caffeine. But I don’t just cover caffeine; I explore whether caffeine truly does act as a diuretic, especially during exercise, and whether or not caffeine can actually be helpful to athletic performance. Should we all be downing mugs of joe or cups of tea before we hit the gym or head outdoors?

Let’s find out.

Dear Mark,

I’ve been told that drinking coffee prior to, or during workouts is a big no-no, because it’s a diuretic and will lead to dehydration, which is no good for performance (or health). But I love an iced coffee right before my workouts. I feel like it helps. It could just be placebo, but if it’s not hurting, I’m okay, right?

I wonder if you could give me the lowdown on what the literature says. Thanks!

Anon

First, let’s tackle the dehydration question. It has undoubtedly become “common knowledge” that coffee is a potent, perhaps the most potent, diuretic, that drinking it is like drinking negative water, and that if you’re stuck on a desert island you’d be better off drinking your own saliva than that steaming cup of joe from the Starbucks that inexplicably decided to set up shop on a desert island. Yeah, there are a lot of scary stories about coffee, but does it hold up to scrutiny?

No. A quick search on PubMed turns up a couple German-only studies with vociferously and unambiguously worded titles but no abstracts (“Coffee does not cause dehydration!” and “Coffee does not dehydrate. New studies of Germany’s favorite addiction: coffee.”), as well as some English ones with abstracts:

  • One from the University of Connecticut measured fluid, electrolyte, and renal indices of hydration over eleven days of caffeine consumption in human subjects. Doses of up to 6 mg caffeine per kilogram of body weight had no effect on body mass, urine osmolality (urine concentration), urine specific gravity (concentration of excreted materials in urine), urine color, urine volume, sodium excretion, potassium secretion, creatinine content, blood urea nitrogen (forms when protein breaks down), and serum levels of sodium and potassium, causing the researchers to conclude that caffeine does not cause dehydration.
  • Another compared hydration markers in patients who consumed either caffeinated beverages (coffee and cola), non-caffeinated beverages (coffee and other sodas), and/or water. The effect on hydration status was essentially uniform across all beverage categories, regardless of caffeine content.
  • And finally, a review from the American College of Sports Medicine found that not only does caffeine not reduce hydration nor induce electrolyte imbalances, it has no effect on heat tolerance during exercise.

I think that settles that. Caffeine does not dehydrate you or cause you to overheat. It’s “safe.” It’s not bad for the active athlete.

But is it actually good? Does it do anything except fail to dehydrate you?

Oh, yeah. Let’s dig into the literature to find out what it can do for your athletic performance.

Endurance Exercise

Most of exercise/caffeine literature centers on endurance training and performance. I remember back when I was running, the most oft-cited benefit to caffeine before a race or training was that it would increase the oxidation of fat, thus sparing muscle glycogen. That sounds nice and tidy, and it would be awesome if it were true, but the most recent evidence suggests that caffeine has little, if any, effect on fat or glycogen metabolism during endurance exercise. So what are we to make of the older evidence that does show a difference in fat oxidation after caffeine ingestion? Or the 1992 study that found caffeine reduced the tendency of muscle to burn glycogen early on during extended bouts of exercise, thus “sparing” it for later on?

It may be that caffeine simply makes exercise more tolerable, makes muscles work harder and better, and allows those exercising to do so harder. One study found that while pre-workout caffeine did not spare glycogen, it did boost the endorphin response to exercise. If endorphins are high, exercise is more tolerable, even enjoyable. If caffeine can increase the runner’s high, it’s also going to make exercise more effective and more self-perpetuating.

Whatever the case may be, the literature is pretty clear that caffeine improves endurance performance, perhaps by enhancing fuel partitioning or making exercise more tolerable and enjoyable.

Anaerobic Exercise

The extent of research into the effects of caffeine on anaerobic performance – think sprints, weight lifting, and interval training – is limited, but useful literature exists. One review, from 2009, noted that while caffeine appears beneficial to speed endurance training (in the realm of 60 to 180 seconds) and high intensity interval training (HIIT), it has limited use in power sports. It may help lower body muscle endurance, but it appears to have a minimal effect on the upper body. The authors propose a number of mechanisms for caffeine’s action, including enhanced calcium transport and the old fat utilization/glycogen sparing thing, but the most promising idea is that caffeine simply stimulates the central nervous system enough to blunt adenosine receptors, increase pain tolerance, and dampen perceived exertion.

What about resistance training? In one study, caffeine ingestion boosted trained women’s 1RM in the bench press (PDF). In another, caffeine seemed to have no effect. A review from 2010 determined that short-term, acute ingestion of caffeine is beneficial in team-based and power sports, but mostly in individuals who did not routinely ingest caffeine. Six of eleven resistance training studies reviewed in the study showed benefits to caffeine ingestion, so the evidence remains fairly equivocal.

Thus, when you drink coffee before lifting heavy things or sprinting, your performance will not suffer – and it may even improve.

It may even be a simpler, less exciting explanation than anything overtly physiological: that the “benefits” of caffeine to physical performance may actually be a cessation of the negative effects of caffeine withdrawal. As Sweat Science points out in a recent post, before double-blind trials on the effect of caffeine on performance, participants must abstain from caffeine for a day or two. If they’re habitual caffeine fiends (as many people are), by the time they begin the study they’re already suffering withdrawals. Studies on cognitive performance and caffeine have found that when you account for the withdrawal effect, caffeine has little to no benefit to performance. Researchers have yet to examine the withdrawal effect in studies on athletic performance, but it appears a likely candidate for at least some of the reported benefit to caffeine consumption.

It’s also important not to lose sight of the fact that most of us are drinking coffee, not popping pure caffeine pills. Coffee contains tons of polyphenols, bioactive compounds that could have beneficial (or negative) effects on exercise performance. Most of the studies are looking at caffeine, so they have to isolate it. But if you’re drinking coffee, shouldn’t you look for studies that examine coffee? There’s a recent one that found ingesting coffee polyphenols increased fat oxidation (PDF). Of course, the caffeine, polyphenol, and other bioactive compound contents of coffee are not stable. Coffee is a food made up of hundreds of factors. It’s not just a source of caffeine. Based on soil conditions, climate, elevation, roast, and variety of bean, two cups of coffee can display remarkably different characteristics, and it’s likely that the effects of each on exercise performance will also differ.

Bottom line, though: if coffee makes you perform better, keep drinking it before, during, or after you workout. At least we can say for sure that it’s not dehydrating you.

How does coffee affect  your workouts? Better? Worse? No effect? Let me know in the comments!

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  1. I love coffee, but haven’t noticed much of a difference surrounding my workouts other than being more awake if I was a little groggy before coffee. I did notice being more energized after drinking more than usual before a long day hike (this could have been the fresh air and sun light though).

    I saw something about coffee increasing stress hormone somewhere (specifically Cortisol). I was hoping it would be mentioned in this post, does anyone know if there is any truth to an increase in stress hormone release from caffeine? specifically coffee?

    a.j. wrote on February 20th, 2012
    • Yes, I’m shocked no one mentioned cortisol!! Coffee increases Cortisol which is why I drink mostly Green Tea (it does not). Cortisol is related to stress/aging and fat retention. I do LOVE espresso with a little coconut milk and the kick it gives my workouts but I limit it b/c of Cortisol and how it amps up my hyperhydrosis. The only Crotisol studies I’ve seem were from Dr. Pericone. Not sure on his credibility…

      NicoleK wrote on February 22nd, 2012
  2. What is missing here is a longitudinal analysis. It is one thing to do a study of a bunch of young healthy coffee drinkers and see what it does to their workouts. It is a whole other matter to see what a 3 cup a day habit does to your adrenals over a 20 year timeframe. And where does this fit into the acidity/alkalinity environment and inflammation? In the end it is always a matter of choice. I don’t think Grok downed a cup a Joe before heading out to snag dinner. But if the point of your workout is to get performance and PR’s and caffeine is a legal way to get there, so be it. However, at some point you need to think about the telomeres at the end of your DNA – at what point does caffeine to work out harder just shorten your life?

    cgk wrote on February 20th, 2012
  3. Can anyone debunk the study that is mentioned here?? http://www.livestrong.com/article/461860-reduced-blood-flow-to-the-heart-during-exercise/
    and in a few other websites.. i know it’s regarding caffeine and not coffee specifically, but it would apply to coffee drinkers and im surprised mark didnt address it. it basically says caffeine before a workout reduces blood flow to the heart.

    Sarah wrote on February 20th, 2012
  4. I’m drinking a nice big cup of coffee as I read this, and I had one this morning before my workout. Glad to see it’s not detrimental to my workouts.

    spincycle wrote on February 20th, 2012
  5. I drink coffee before, during and after CrossFit workouts and can attest without a doubt that it absolutely improves performance, especially at 5:30 in the morning. Coffee rocks!

    Garth wrote on February 20th, 2012
  6. I dig a coffee, never been addicted, never had withdrawal when I’ve drunk it regularly. I did try chucking it once before I went Primalish because I was having such bad gut issues. (And by that I mean, the shits, all the time.) But now that I’ve kicked the grains habit, coffee doesn’t affect me other than the really good poop thing. It never really occurred to me to have a coffee before a morning workout, but now that that’s out there as okay, I might just do that, because I usually have to wait for the uh, morning poop to have a good workout and coffee definitely … moves things along.

    Anna wrote on February 20th, 2012
  7. My experience seems to indicate that reaction to caffeine is a uniquely individual experience. A long time ago, I finally figured out that most of my bouts with insomnia could be attributed to having consumed too much caffeine in one form or another after 3 PM. To this day, if I’m at a party or just don’t think about it and have too much chocolate or a cup of tea after about 3 PM, sure enough, I find myself too wired to sleep that night. But I know lots of people who drink coffee before going to bed with no problem whatsoever.

    I don’t care for coffee myself, but I also learned many years ago that a diet coke when I was dragging on a long bike ride would perk me right up and have me passing my fellow riders. My husband would always notice right away when I’d sneaked some serious caffeine on a ride because he would begin to have trouble keeping up with me. He’s tried it, and it doesn’t do a thing for him.

    I generally don’t ingest much caffeine, maybe one square of dark chocolate in the morning most days of the week, just because I like chocolate, but it doesn’t seem to give me the kick that a diet coke or caffeinated energy drink would give me. I’m not sure what I’ll do this summer when I need that kick on a bike ride since I’m now trying to live primally. Hopefully I’ll find I won’t need it

    happybiker50 wrote on February 20th, 2012
  8. I typically drink a cup of coffee about an hour or so before I workout. To combat dry mouth sensation, try chewing gum during your workout.

    Mike wrote on February 20th, 2012
  9. I’m a HUGE advocate for pre-workout coffee.
    It works just as well as any pre-workout supplement on the market.
    Always a controversial subject of course, but it’s great to have the hard data.
    Nice one.

    Clint wrote on February 20th, 2012
  10. I used to drink the mega-hyped pre workout stims like n.o explode, jack3d, n.o shotgun (don’t judge me, sucker for marketing). They did the job, gave me energy to hit the gym and hit it hard. But now I just mix a cup of black coffee in my pre workout shake. Does the job. And better on the wallet.

    Carry on.

    JMJ wrote on February 20th, 2012
  11. I take advantage of the perks of caffeine before/during races (Olympic/Half IM Triathlons). I definitely believe that caffeine helps tremendously during endurance races. I usually take gels with a caffeine supplement throughout the race. I feels like it gives me a boost of speed and my pain threshold seems to reduce.

    For everyday training, however, I tend to avoid drinking coffee before intense workouts (TTs on the bike/running intervals). The elevated heart rate becomes more uncomfortable and too stressful due to the caffeine during interval sessions. I can handle the stress on race day but not for everyday training. I also feel a lot better post workout without the caffeine in my system.

    Brandon wrote on February 20th, 2012
  12. Coffee and caffeine are NOT synonymous!

    I’ve found that decaf coffee has the same “moving” effect on my gut as caffeinated and perks me up about the same too. Add to that, I could (but no longer do!) drink a 20oz non-diet Mountain Dew right before bed and have no problems getting to or staying asleep. But coffee, even decaf in larger quantities, much after lunch, and I’ll be up for hours.

    These days my coffee is at most either two cups during the morning at work (one teaspoon of raw sugar and a dollop of whole milk) or else one homemade latte with a smidge of honey and vanilla (I’ve recently found where I can get raw Jersey milk and goat milk). I tried it with almond milk, and maybe it was that particular milk, but I thought it was singularly nasty.

    I haven’t tried drinking coffee or caffeine specifically for workouts, but anything that can help with motivation can’t hurt. As far as hydration, I don’t find coffee makes me pee anymore than an equivalent amount of plain water.

    Nancy wrote on February 20th, 2012
  13. I find that if I drink a cup or two of delicious coffee AND a couple full glasses of water, wait an hour before running and let some of that water make it back out, then my workout doesn’t end up with dry mouth or having to pee. I think you just have to find what amount of water and coffee works for you, and you CAN’T have just drank two cups in a half hour and then go. You have to pee first at least once. Coffee makes my workouts five times easier.

    AdieBeatty wrote on February 20th, 2012
  14. I don’t drink coffee very often because it actually makes me sleepy, with the exception of a frappe like 2 hours before bedtime. Then I’m super hyper. I’m sure it’s got something to do with the high amounts of sugar. Plus, I don’t really like the smell of it, especially the first thing in the morning.

    Alessandra wrote on February 20th, 2012
  15. Hmm…that’s strange. I absolutely love the taste of coffee and drink a cup of black coffee on my rest days, but whenever I consume any sort of caffeine on a workout day I perform horribly.

    Before I went primal, any form of caffeine – soda, energy drinks, coffee – would make me less coordinated when I played sports. That being said, the sports I did (badminton and martial arts) all required lots of precise movements, so maybe that was why caffeine had a negative effect. Too much arousal isn’t good for mentally difficult/complex activities, or at least that’s what my old psychology textbook told me.

    I’m not absolutely sure if my performance worsens while lifting heavy weights since I’ve recently been avoiding caffeine on workout days, but I have a feeling my power cleans won’t be as good because of the complexity of the exercise. I guess I’ll try drinking coffee on a weightlifting day a few times just to see what happens.

    Binh Ho wrote on February 20th, 2012
  16. I love a cup of strong hot coffee in the morning, it does wonders to perk me up.

    I gotta be at work at 7:30am everyday. ‘Gimme my coffee or I will hurt you.’

    Caleigh wrote on February 20th, 2012
  17. Read the latest online edition of life extension magazine…they have a fantastic article of the great benefits of multiple cups of coffee a day….I myself am hardcore…I will put 2 tsps of instant coffee directly in my mouth and chase it with water…too lazy to heat the water and clean the cup….works for me…lol

    Robert wrote on February 20th, 2012
  18. I’m pretty sure that caffeine increases the risk of arrhythmias during long periods of exercising- long runs for example (10+ miles).

    Hanieh Razzaghi wrote on February 20th, 2012
    • Yeppir! PVCs like crazy. No thank you, Mr. Coffee.

      Extra potassium for me and I feel great. Personally, I don’t care for the “my chest is about to explode” during my workouts.

      Algboy wrote on February 20th, 2012
  19. Coffee makes me feel calm in the mornings and like wonder woman during workouts. I would never stop drinking it- even if mark said to.

    Andi wrote on February 20th, 2012
  20. my pre-workout prep involves a tablespoon of almond butter and a small piece of bittersweet chocolate. the caffeine from the chocolate is just enough of a spark to keep things rolling.

    rik wrote on February 20th, 2012
  21. Not a big coffee fan. One cup, black, warm — not scalding — in the morning. Done for the day.

    In the 80s I used to split a pot in the morning and also did several glasses of diet Pepsi {cringe} during the day. I started having PVCs that scared the carp out of me. Cut WAY back on the caffeine.

    I also didn’t like the way my insides started percolating after more than a cup or two. Not a good thing during a hard training run.

    I guess I wouldn’t do well in Seattle. Coffee during the day? YUUUUUCHHH!!!

    Algboy wrote on February 20th, 2012
  22. I still remember my best day of sparring class in my Taekwondo training days was when I had a double mocha right before class. My master instructor even commented on how much ass I kicked that day ;)

    Stephanie wrote on February 20th, 2012
  23. Some interesting comments on the Demon Coffee.
    I have been an exercise enthusiast for many years now, it’s been a big part of my life. I did it because it is a great stress antidote, and I enjoyed it.
    Managed a couple of marathons, and Kayak Ultra marathons, weights, Mountain Biking, all good fun.
    Always ate and drank whatever I wanted, fried food, steaks, lots of fruit and vegies, plenty of whisky, wine, and COFFEE!
    Looking back, as I have just turned 70, I note that almost everything I’ve ever eaten, drank, or done- someone has been either for or against, at different times.
    My advise? If you enjoy it, coffee drinking or not, or any other dietary fad….do it. Probably won’t make much difference longterm anyway.

    JB wrote on February 20th, 2012
  24. anything wrong with taking a caffeine pill 200-400mg prior to working out? I don’t like the taste of coffee.

    Eric wrote on February 20th, 2012
  25. coffee tastes terrible I have no problem with caffeine but what else is in coffee? If it is a super health beverage why does it make peoples breath smell like ass? and sweat smell worse?

    Its a product that you are meant to buy and become addicted to, and its an extremely thirsty crop , not very enviro friendly.

    Bob wrote on February 20th, 2012
    • Well since beauty is in the eye of the beholder, taste (good or bad) must be on the buds of the imbiber =)

      As for the smelly breath: I think most of us agree that garlic is a very healthy food (the russian penicillin, right?). I assure you that smell and health in this sense don’t have anything in common.

      What else is in coffee? Here’s a few:
      http://www.wired.com/science/discoveries/magazine/17-10/st_coffee

      As a home roaster I can tell you that the amounts of the different compounds vary greatly depending on the origin/soil of the bean (well actually it’s a seed),your roast profile since they develop/diminish at different temperatures.
      Bonus fact: Coffees chemical composition is around 2,5 times more complex than red wine. -always a great kicker when battling hobbies with a wine connessieur ;-)

      If you worry about the environment (as we all should) go for organic fair trade coffee -or even better direct trade. There are hundreds of great coffee farms to choose from in this category.

      Andreas wrote on February 21st, 2012
      • Almost forgot:

        Most studies done on coffee and health point toward coffee consumed in moderation (generally 6 or less cups a day) have a beneficial effect on preventing Alzheimers, Parkinson disease (one study up to 75% reduced risk!) and diabetes.
        In addition, skin cancer risk may be reduced by caffeine and/or caffeine sodium benzoate (Study in progress).
        Lastly let’s not forget the antioxidants. Green tea may be the winner here, but coffee is on board as well.

        Andreas wrote on February 21st, 2012
  26. I’m not a coffee drinker, but I do have green tea. I notice that even that small hit of caffeine definitely improves my workouts! On the days I don’t have it pre-workout I notice I may be slightly more sluggish. And there is health benefits to green tea too so I’m just gonna keep on drinking it

    Sarah @ The Healthy Diva wrote on February 20th, 2012
  27. I prefer green tea. Especially the Japanese Sancha, or the Chinese Bancha.

    Combined with some dark choclate, it feels like heaven.

    Steven wrote on February 20th, 2012
  28. What do you all think about caffeine tablets ? I bought some on spec because I can’t stand the taste of coffee (like the smell though). They’re 100mg per tab, I’ve been having one before the gym. Not sure if it is a placebo but I seem to be able to do more.

    davecoconutty wrote on February 21st, 2012
  29. Are you kidding me? Coffee doesn’t dehydrate? ya ok.. Everytime I drink it I urinate way more and feel dehydrated afterwords. I’m gonna have to disagree with pubmed. I’m sure I can find several sources on pubmed that supports that coffee dehydrates.

    lulz wrote on February 21st, 2012
  30. Mark,
    Thanks for your great article. No surprise caffeine boosts mood and performance. But I wonder:
    1. How does caffeine affect long term health? Particularly cardiac health.
    2. How does caffeine affect our ability to maintain lean muscle mass and bone density, especially as we age?
    I’d love to hear your thoughts on this. Thanks again.
    Kaden

    Kaden wrote on February 21st, 2012

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