Caffeine and Running

imageCaffeine is everywhere these days. It comes in gum, gels, and jellybeans, and even in sprayable cans, powdered form, and, briefly (pun intended), in underwear. And certainly, for many, it comes in the form of a morning cup of joe.

Runners especially seem to cling to the caffeine. After all, training can be exhausting, often taking place in the wee hours of the morning or after a long day at work. We need a jolt to get out the door … and maybe a caffeinated gel to get through the final miles … and maybe another cup to revive us enough to tackle the rest of our jam-packed days … and then maybe an afternoon latte to stagger through to 5:00.

But there’s a lot of talk about caffeine and whether it’s good or bad for us, especially as runners. Does it give us a boost or give us the trots? Does it dehydrate or replenish? If we drink that morning coffee day after day (along with the afternoon mug) will it still give our run a boost? Below is a summary of what we know about our daily cuppa.

The Good

Caffeine is a known performance enhancer, so much so that it used to be banned by WADA. Caffeine helps reduce perception of effort (it feels easier to nail a fast pace), increases muscle contraction, and ups the circulation of free fatty acids during high intensity workouts, sparing those precious carbohydrate stores. And of course, it perks us up during exhausting training weeks. Many of us couldn’t get through the daily grind without our morning grind. In fact, one reason it’s no longer banned is its ubiquity in our culture; 85% of Americans consume caffeine daily.

The Bad

Sadly, there’s bad news brewing too. If taken before or during exercise, caffeine can reduce blood flow to the heart. This is troubling because the heart is pumping harder during exercise, so it needs more blood, not less. Some speculate this may be a cause of sudden death in marathons, although no death has been specifically linked to caffeine yet. Based on the possibility, the International Marathon Medical Directors Association warns runners not to consume more than 200 total milligrams of caffeine before and during a race. Those most susceptible are people who don’t regularly consume caffeine, have heart disease, or take it in high doses (like those found in energy drinks). If you have heart trouble, please don’t use this post as a reason to start chugging energy drinks. Talk to your doctor first and be cognizant of the caffeine levels in your drinks and gels… and how quickly they can add up.

The (Could Be) Ugly: Bathroom Issues

This could fit in the good or bad categories, depending on your situation. Some runners love a cup of coffee before a run; it gets things moving so there’s no need for a bathroom stop later. Others find it works a little too well in that area and end up with the trots. If you’ve been experiencing bathroom issues on your runs lately, you might consider examining your caffeine consumption and see if adjusting it helps.

One oft-cited con of caffeine is that it makes you pee more often, potentially dehydrating you. Fortunately, this has been debunked in recent years; there appears to be no difference in fluid balance (i.e. urine volume) after drinking water or caffeinated beverages, particularly if you’re a regular caffeine user.

How Much?

To get a helpful performance boost, the recommendation from most studies is 3-6 milligrams per kilogram of body weight. For a 130-pound women, that’s about 180-350 milligrams of caffeine, or around 12 ounces of strong coffee or three 8-ounce cups of tea. (Note: the high end of this is much more than the International Marathon Medical Directors Association recommends.) More than that doesn’t seem to provide any additional benefit.

Obviously, it’s important to know your body. If you have heart problems, are on certain medications, or are pregnant, you may need to limit your intake. Furthermore, people metabolize caffeine at different rates. A genetic test can tell you if you metabolize caffeine quickly (you get a jolt quickly, but it fades quickly too) or slowly (it takes longer to work, but lasts longer too). But based on your own experience, you probably already know this without knowing your genes. If caffeine takes a while to kick in, you might want to try drinking it an hour or so before the race, while if it hits you quickly, you might try taking a gel just before the start and supplement during.

Coffee beans overlayed with the word "life"
Could you give it up temporarily for a pay-off on race day?

Do You Need to Give It up Before A Big Race to Get a Boost?

Some coffee addicts have success tapering caffeine leading up to the race. Since your body is habituated to its daily dose, lowering your tolerance may allow a cup of coffee or caffeinated gel to give you a bigger boost on race day. But some think it’s not worth the misery of withdrawal symptoms when you’re already cranky from tapering. The science is mixed; there seems to be no consensus whether your tolerance matters for performance benefits.

The Saltines are mixed too. I tried cutting back on tea (my main caffeine delivery system) before my last race, but didn’t sense much difference. But Barley, an avid coffee girl, has had great success. If you want to try it, she recommends slowly easing off it starting one to two weeks before the race. To counter the withdrawal, she starts by drinking half-caf and then progresses to decaf.

Coffee for Recovery: Is It the New Chocolate Milk?

Consuming carbohydrates along with some protein, like in chocolate milk, after a long workout is crucial to replenishing fuel stores and promoting recovery. But research also shows that combining caffeine with the carbs could give an additional boost. One study found that a post-workout combination of carbs and caffeine led to increased glycogen stores (the energy supply we use up during long runs) a few hours later compared to post-workout carbs alone. Another study found the combo may help runners bounce back after a long workout; people given both carbs and caffeine performed better on a sprinting test a few hours later. (Some caveats: both studies were small and used a LOT of caffeine, equivalent to about 5 cups of coffee.)

Though the research doesn’t seem as robust as for chocolate milk, it is comforting, especially when you’re slamming a coffee post-run on the way to work. Who knew that was helping you recover?

In Summary

Overall, the studies provide some good news for coffee lovers to contemplate as they sip their morning mug. But for those new to caffeine, start slowly (perhaps with tea or a gel with 25 milligrams) and if you are at risk for heart trouble, consult your doctor first.

How do you feel about caffeine? Do you use it for a performance boost or a get-through-the-day necessity? 

I'm a science journalist with a background in neuroscience and a love of running marathons and baking marathon-worthy feasts. I started out as an over four-hour marathoner but whittled my PR down to qualify for the 2016 Olympic Trials. I write about the importance of chasing big dreams and -- as I'm currently pregnant with my first -- getting ready to chase around a little one.

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  1. I LOVE my morning cup of coffee and especially before a run. It definitely helps to get things moving (digestion wise) which I absolutely need before I hit the road. I’ve never experienced any adverse affects from it, but I do tend to keep it on the moderate side. I’ll usually have about a half a cup before a run and even on a race morning. All I need is just a little bit!

    Great post, BTW! Lots of helpful info!

    1. I agree about a half cup before a run. I do cold coffee race mornings, but when it comes to training runs half cup of regular hot coffee does the trick to wake me up and get me ready to run.

  2. Thank you JEEBUS! I could not and will not ever forgo coffee on purpose. I successfully did it during one of my three pregnancies, but that was when my will for perfection was at its strongest. I made it a month with my second pregnancy and then caved. Then with the third, strangely, coffee – even just the smell – made me hurl until 12 weeks and then overnight coffee was amazing again! But, my doctor made me stop caffeine for a week around 6 months and it was torture. The headaches and the brain fog! So awful. Thank goodness I was cleared to hit it again, because I’m not sure I would have the will to get out of bed without coffee. I get excited to wake up as I’m preparing the coffee at night to automatically brew in the morning. The other day I was running and a car drove by with the driver sipping from a travel mug and I felt intense jealousy. Maybe I have a problem, but I’m ok with that. Where’s my mug?!

    1. Well obviously I’m a tea drinker, but I can relate to the intense jealousy when I’m running and see someone with a mug. If it’s summer and they are drinking a tall cup of iced goodness, or if it’s winter and they are sipping some hot deliciousness, I am SO jealous. I know it’s coffee, but it also looks like tea, and it’s always exactly what I want/NEED in that moment.

  3. I use caffeine/coffee for my training in a few ways. Coffee through training helps the exhaustion of it all, but then like you said I prefer to back off before the race because then when i DO have caffeine on race day it feels like it super charges me! Race morning is cold coffee early, then I use caffeinated gels during the race.

    Random TMI trick: I brew coffee the night before a race, and let it sit out all night. In the morning when i get up I drink my cold coffee- it gets “things” going pretty quick and haven’t had issues “getting everything out” before a race. hot coffee isn’t as effective for this (in my experience)

    1. Interesting! Re cold coffee vs hot. For maximum enjoyment I like HOT coffee even when it’s really hot outside and I am so anal-retentive about how hot it has to be. I feel elderly about my coffee persnicketiness.

      1. I don’t necessarily LIKE the taste of the cold coffee (it’s not even close to the same thing as iced coffee…which I do love). But cold coffee does the GI trick…which is more important than my taste buds come race morning.

        1. Isn’t it interesting how every body responds differently? Hot coffee does the trick for me. Cold coffee is delicious, but I need the hot coffee to get things moving.

  4. Coffee is the love of my life. A day without coffee is like…. well, I can’t even imagine. 🙂 I thank my lucky stars that coffee doesn’t cause me any GI distress, because I NEED coffee before I run in the morning. I always have at least one cup… sometimes two if I have the time. I contemplated doing the caffeine taper before a race, but I don’t think I could do it!

      1. I tried a coffee fast the week leading up to a half marathon last year. Being a daily coffee drinker, I was surprised that I didn’t have any side effects when I stopped cold-turkey. I really didn’t notice any significant energy increase or performance enhancement when I chugged some high-octane coffee before the race. I was very disappointed. Going to try it again before a race in late April. Hope it works this time.

  5. Thanks for this Tea, very interesting!

    Something I recently learned during a sleep hygiene study that runners may want to think about as well: the effect of caffeine on your sleep cycle is tremendous. During this study, the doctors told me it takes 12 hours for caffeine to fully leave your system. So if you want a 10pm bedtime, don’t drink any caffeine after 10am, or it will affect your sleep quality.

    1. Yes, definitely a good point! It does vary a lot but if anyone has trouble sleeping they should consider this. It’s crazy how long it can affect you!

  6. Thank you Tea (and the universe) for all this good news. I drink a lot of coffee… 2-3 cups in the morning, plus I love an Americano post-run. and will often do a latte in the afternoon. I found out, through a genetic test, that I flush caffeine quickly- though I noticed that before science confirmed it. I love the ritual of it in the morning from grinding the beans to the warm mug snuggled in my hands or against my cheek… My add-in to home brewed right now? A teaspoon of honey, cinnamon, and milk. Joy.