Fitness

Here’s What Your Pre-Gym Coffee Does To Your Workout

Plus, how much is too much.

A woman drinks her coffee before getting ready for a workout. Here's how caffeine helps workouts.
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When your alarm goes off at 5:30 in the morning to tell you it’s time to hit the gym, you’re ready to go — you left your workout clothes out last night and your sneakers are already by the door. First things first, though: coffee. But how much caffeine is good for a workout, and how much will just give you a severe case of the jitters?

How Does Caffeine Impact Your Workout?

Coffee’s impact on your workout doesn’t start with your muscles — it starts with your brain. “Caffeine is a drug and acts as a central nervous system stimulant so when it hits the brain, people who are using it will usually feel more alert and awake,” says Dr. Michael Lee, M.D., a family physician and the medical director of One Medical in Orange County. One of the ways that caffeine gives you that kick of wakefulness is by blocking the effect of the neurotransmitter adenosine in your body. Adenosine builds up during the day so that you feel sleepy by the end of it — hence your daily desire for an afternoon coffee pick-me-up. But when you down a matcha latte, your natural tiredness gets a bit delayed.

Studies seem to say that some coffee before your long-distance run or biking session might be helpful. According to a 2019 review published in the British Journal of Sports Medicine, the performance-enhancing effects of caffeine on exercise may happen largely when folks are trying to build their cardiovascular and muscular endurance (going on a run and lifting weights for a high number of reps). The review found that caffeine might also be helpful when people are trying to build strength and anaerobic power (with the kinds of stuff you do in your weekend boot camp or CrossFit classes).

But your morning latte is not the Powerpuff Girls’ Chemical X. Dr. Lee explains that more research on caffeine and exercise is still needed, especially since most studies have participants ingest highly-concentrated caffeine powder before their workouts, rather than a normal coffee. So the effects of your casual, everyday cup of Joe on your morning run are yet to be scientifically determined.

Can You Have Too Much Coffee Before A Workout?

There can always be too much of a good thing — especially with a pre-run espresso. “Individuals tend to start seeing more side effects such as shaking or tremors, anxiety, or increased heart rate when individuals take higher doses of caffeine,” says Dr. Vivek Cherian, M.D., a Baltimore-based internal medicine physician. For folks who are regular coffee drinkers, around six cups of plain black coffee might be considered too much, for example.

The Food and Drug Administration (FDA) recommends a maximum intake of 400 mg of caffeine per day, which amounts to about four or five cups of coffee. “Be sure to look at how much caffeine is any other product you might consume,” Dr. Lee advises. You’ll also want to make sure you’re drinking plenty of water before, during, and after your workout, Dr. Lee says — sure, there’s water in coffee, but no, it doesn’t count toward your hydration needs.

How Much Caffeine Is Good For Your Workout?

If you’re not really a coffee drinker but your bestie is chugging highly caffeinated pre-workout that they have every day, you probably won’t want to jump right in and try theirs. “If you consume coffee daily (or anything with caffeine, such as energy drinks, soda, etc.), your body does build up a tolerance for the caffeine,” Dr. Cherian explains. The more tolerance you have, the less a triple-shot latte will impact you in the gym.

In other words, the amount of coffee you’ll want to boost your workout depends on what you tend to do in your morning routine. Dr. Cherian recommends starting at around 150 mg of caffeine — that’s an 8 oz cup of coffee about an hour before your workout. Pay attention to how your buzz seems to be affecting your workout and adjust what’s in your Yeti from there.

Experts:

Dr. Vivek Cherian, M.D., Baltimore-based internal medicine physician

Dr. Michael Lee, M.D., family physician, medical director of One Medical in Orange County

Studies Referenced:

Grgic, J., et al. (2019) Wake up and smell the coffee: caffeine supplementation and exercise performance—An umbrella review of 21 published meta-analyses. British Journal of Sports Medicine.