Caffeine is a potent performance enhancer. It's one of the few ergogenic aids that has an immediate effect. As an antagonist of the inhibitory neurotransmitter adenosine, caffeine is excitatory, which translates to improved focus and mood and a reduced perception of pain and exertion. Given that climbing at your limit requires a keen focus on the next move even while your muscles fatigue and burn with exertion, caffeine has a lot to offer.
While you can buy caffeine supplements in stores, it’s much more common to get one’s dose “naturally” through a variety of brewed drinks; tea, coffee, and mate are all rich in the drug. These drinks also contain other potentially ergogenic ingredients as well, as do modern alternatives like energy drinks and sodas and less-thought-of alternative caffeine sources like chocolate. If your goal is maximum performance, then—and you’re not attached to any beverage already—is there a single reigning source that would provide the greatest advantage considering all its potential benefits combined?
A Few Notes
In this article, I use USDA reference values wherever possible, but many factors affect a food or drink’s true nutritional content, including caffeine. Amount of product used, steeping time, source, and growing conditions (to name a few) all alter actual values, so the values used in this article should be viewed as averages.
It’s also important to note that any plant-based food is a sum of thousands of chemicals, not only the ones discussed below. When it comes to short-term climbing success, most of these chemicals are irrelevant and not discussed, but they could potentially be beneficial in terms of general, long-term health.
- Caffeine: 96 mg/cup; 64 mg/1 fl oz shot of espresso
- Chlorogenic Acids: 70-350 mg/cup
The classic caffeinated beverage no matter how you dress it up. Coffee is often assumed to be nutritionally boring compared to its rivals, but its banality masks a rich chemical make-up.
Aside from caffeine, coffee is host to a group of polyphenolic compounds collectively known as chlorogenic acids. Chlorogenic acids are likely to have a number of small, pro-health effects—there is a general scientific consensus that 3-4 cups of coffee is good for your health—but they have also been studied for weight loss. Unfortunately, the effect is quite small, and you’re unlikely to have a weight-based performance advantage just because you’re a coffee drinker.
Black Tea & Green Tea
- Caffeine: 47 mg/cup (black); 29 mg/cup (green)
- Theaflavins/Catechins: 10 mg theaflavins (black); 70 mg catechins (green)
- Theanine: 24 mg (black); 8 mg (green)
“Black” and “green” are broad categories for tea, and perhaps you prefer something in-between (like oolong), younger (like white), or fermented (like pu-erh). It doesn’t really matter, though, because despite the diversity of true teas available the chemical composition remains similar—unoxidized teas contain catechins, which oxidation converts to structurally and functionally similar theaflavins.
Catechins and theaflavins have two potential benefits for short-term performance. The most well-studied benefit is a synergistic increase in fat oxidation alongside caffeine, but unfortunately (as with coffee) this benefit is small: about 5-10 calories worth per cup of tea. A smaller amount of research suggests catechins and theaflavins could improve capillary circulation after brief periods of ischemia, such as a climber may experience during forearm contraction while climbing. The threshold for this effect? Approximately seven cups of tea, almost half a gallon.
Green tea is often cited as being rich in a focus-boosting amino acid known as theanine, but this is wrong on two counts. First, black tea is significantly richer in theanine (about 200% more per cup). Second, while theanine may boost focus, it’s difficult to separate its effect from that of caffeine. Regardless, you’d need to drink 2 cups of black tea or 6 cups of green tea to reach the levels of theanine used in research.
The moral of the story: if you’re going to drink tea, drink a lot.
- Caffeine: 85 mg/cup
- Theobromine: 25 mg/cup
Mate is a newcomer to many of our palates but has a longer history in South America. Since mate is leafy like tea, it feels right to compare it to tea, but it’s actually nothing like tea. A cup of mate is more like coffee mixed with chocolate—it has the high caffeine of coffee and the theobromine of chocolate. (In case you’re wondering, it tastes nothing like either. Or like tea.)
Structurally, theobromine is like caffeine, and when given separate from caffeine it has similar effects. In combination with caffeine it behaves differently because caffeine has a much higher affinity for our brain’s adenosine receptors, so theobromine is cast aside to affect our respiratory and circulatory systems instead. There it increases our heart rate, opens up our blood vessels, and relaxes our bronchial muscles, all of which can improve climbing performance.
Caffeine also does these things, of course, but theobromine’s effects last around twice as long, making smaller doses more potent. Beware the other edge, though—the longer half-life means theobromine can stick around to disrupt sleep (after caffeine has metabolized away), so proceed with caution in the afternoon.
Before we move on to the other theobromine-rich source of caffeine, I want to note that theobromine is the chemical responsible for the toxicity of chocolate in dogs, so don’t give your furry friends any mate. I normally wouldn’t assume anyone does this, but we live in a world where horse racing theobromine doping scandals exist so who knows what people do with their animals anymore.
- Caffeine: 23 mg/oz
- Theobromine: 227 mg/oz
For chocolate, we’re looking at food, not drink; you can make chocolate drinks, of course, but they’re rarely rich in actual cocoa solids unless you’re actively trying. Solid chocolate, on the other hand—particularly dark chocolate—is rich in theobromine (as well as general health-improving polyphenols).
We’ve already discussed theobromine, so there’s no need to beat a dead (theobromine-doped) horse. Dark chocolate is significantly richer in theobromine than mate, though, so if the long-lived benefits of theobromine are your goal you may be better off dissolving a few ounces of extremely dark chocolate in your coffee (or tea; I won’t tell you how to live).
- Caffeine: 20 mg/cup
- Sugar: 23 g/cup
Soft drinks used to contain all sorts of chemicals that could be beneficial to performance, like cocaine. Now it’s just caffeine-infused, bubbly sugar-water. The sugars can certainly be beneficial—carbohydrate is the most potent ergogenic aid we know of—but they’re not unique to soda, and hopefully you’re bringing other, healthier food to the crag in addition to your caffeinated beverage.
- Caffeine: 77 mg/cup
- Sugar: 27 g/cup
- Taurine: 1 g/cup
There are many brands of energy drink, but they all stick to the same general formula: lots of sugar, a handful of B vitamins, and a gram of taurine. The B vitamins are largely irrelevant (they have no acute effect and deficiencies are rare), so any benefit of an energy drink will come down to taurine.
For how popular taurine is, it’s poorly studied. Part of the problem is that the most common intake method for a taurine supplement is through energy drinks, which means the data is confounded by the presence of caffeine. One recent meta-analysis excluded these types of “energy drink” studies and found a marginal (but statistically significant) benefit of taurine in endurance exercise. Would that benefit help a climber? Probably not. A runner? Probably still no. For all their marketing, energy drinks can basically be understood as even more caffeinated, even more sugary water than soda.
Caffeine Is the Real Winner
Most of our commonly consumed caffeinated beverages are a complex smorgasbord of chemicals, and in a typical fashion many of those chemicals have small benefits. At the end of the day, though, they all play second fiddle to caffeine. Caffeine has such a large, observable benefit that it’s tough to compare the marginal benefits of any other chemical to it.
If you have a preferred drink, chances are you find it pleasing and you know how to titrate your intake through the day to maintain a reasonable level of energy and focus. These are the biggest benefits to caffeine, and it’s tough to argue why you should give up that reliability for marginally better fat oxidation. But it’s nice to know they exist, at least to build a veneer of rationality in our drink preference.
As a certified sports nutritionist (MS, CISSN), Brian Rigby works with climbers and other athletes at Boulder’s Elite Sports Nutrition in Colorado, writes at Climbing Nutrition, and discusses the scientific aspects of climbing performance as co-host of the ClimbSci podcast.
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