Coffee, good or bad for health and fitness?

You’ve heard that coffee is good for you, but I also bet you’ve been told coffee is bad for you and that you’re better off staying away.

So which one is it?

I hold a strong bias in favour of drinking coffee as I love the stuff and it makes life better. At the same time, I want to explore the scientific literature on coffee consumption and weigh up the positives and negatives to see whether it deserves a place in your daily routine if you’re on a pursuit for better health and fitness.

How does coffee ‘work’?

One of the main reasons you may drink coffee is to feel more awake and energised.

You can thank caffeine for this, which works to block ‘adenosine receptors’. Throughout the day, and as you expend energy, a neurotransmitter called ‘adenosine’ starts to build up in your brain.

As this neurotransmitter builds up, it promotes your need for sleep. Because caffeine blocks the receptors that adenosine binds to, your need for sleep is reduced and you feel more awake.

It also increases the release of dopamine (your drive to pursue something), noradrenalin (contributes to higher arousal, attention, learning/memory etc.), and glutamate (your brain working and ‘firing’ better).  (1)

With a reduction in your feelings of tiredness and an increase in arousal, drive, attention etc., there’s a good chance you can feel coffee ‘working’.

With higher dosages of coffee (and thus caffeine), there are other mechanisms that take place that benefit the function and force of your muscles, which is where some of the physical performance-enhancing effects come from.

So it works, but is it healthy?

Let’s look at this umbrella review (covers a huge amount of quality evidence) by Poole et al., titled “Coffee consumption and health: umbrella review of meta-analyses of multiple health outcomes” (2017).

Here are some highlights:

- High coffee consumption (vs low coffee consumption) was associated with a lower risk of seven different cancers! (2)

- The largest reduction in your relative risk for cardiovascular disease was achieved with three cups of coffee a day. (2)

- Compared with no consumption, consuming three cups a day was associated with the largest reduction in your risk from dying of any cause. (2)

- High consumption associated with lower risk of type 2 diabetes compared with low consumption. (2)

- Any coffee consumption was associated with a lower risk of a number of liver issues (eg. fatty liver, liver fibrosis, liver cirrhosis) (2)

- There were also favourable associations with consuming coffee and depression, and a reduced chance of developing Parkinson’s and Alzheimers. (1) (2)

Where do these health benefits come from?

There are over 1000 bioactive compounds (chemicals that have positive effects in the body) in roasted coffee (2).

There’s a good chance some of these bioactive compounds are what’s responsible for the beneficial health effects that have been associated with drinking coffee.

For example, did you know that the total antioxidant content of coffee is on a similar level to cocoa and tea (green and black)? (3)

So, if you’re having two to three cups a day, that’s a pretty big source of your total antioxidant consumption across the day and is bound to have a positive impact on your health.

Struggle to consume coffee due to how caffeine makes you feel?

Having two to three cups of coffee a day can be too much for a lot of people, especially if you are prone to the anxiety-inducing effects of caffeine.

So you want all of these great health benefits, but you don’t want the accompanying anxiety from consuming too much?

The good news is that a lot of these benefits (including the large antioxidant content) still exist in decaffeinated coffee, you just don’t get the high caffeine content.

There’s still a beneficial association with an intake of two to four cups a day of decaffeinated coffee and a reduced risk of dying from any cause (2).

Decaffeinated coffee can also be useful if you want to drink another coffee after midday (and gain the health benefits) without letting your sleep get disrupted by caffeine.

Will coffee help you work out?

Want to perform better in your training sessions?

Here lies another impressive advantage of consuming coffee thanks to its high caffeine content.

Looking at another umbrella review, this one titled “Wake up and smell the coffee: caffeine supplementation and exercise performance–an umbrella review of 21 published meta-analyses” (Grgic et al., 2020) concluded that caffeine improves your exercise performance in a number of ways.

There’s evidence of improvements in aerobic endurance, muscular strength, exercise speed, power, muscle endurance and jumping performance! (4)

How much coffee to consume to get these performance enhancing effects?

The general consensus is that around 3-6mg/kg of caffeine should be consumed to get the best performance-enhancing effects (4) (5).

How much coffee is this?

The caffeine content of coffee varies significantly based on how it is prepared, what variety it is, how that variety was roasted and so on.

Brewed coffee has an average of 107-151mg of caffeine in an average cup (6)

So for the best performance-enhancing effects, you need 3-6mg of caffeine per kg of bodyweight; an average cup contains around 100-150mg of caffeine. You can do the maths for your bodyweight!

“As a broad rule of thumb, two cups of coffee, consumed around 60min before exercise, should exert an ergogenic effect in most individuals.” -Grgic et al., 2020

What’s bad about coffee?

So my bias has probably been pretty clear, there are a lot of benefits and the only negative I’ve listed is the fact that it can potentially disrupt your sleep.

There are different factors that contribute to how someone processes coffee and the caffeine in it so, as always, it depends on the individual. However, with higher dosages of coffee, caffeine can have anxiety-inducing effects. (1) (5)

There’s also the potential for insomnia (if you’re having it too close to bed time) and high blood pressure, but all of these side-effects can increase the more you consume. (1) (5)

Withdrawal symptoms: Withdrawal symptoms are another side effect that occurs with people who consume a lot of coffee, but surprisingly it can also occur with people who have only had moderate intakes. Headaches and fatigue are the main symptoms and can hang around for about a week!

If you’re pregnant or have a health condition it would also be wise to speak to a medical professional as the research isn’t as clear-cut in those areas.

Want to avoid the potential negatives of coffee intake?

For anxiety-inducing effects: Experiment and find a dose that is right for you. Another strategy is to pair your coffee intake with L-Theanine supplementation. L-theanine is a compound found naturally in green and black tea that can promote a more relaxed feeling (without drowsiness) and has been shown to pair well with caffeine – there’s even evidence that the combination can improve your cognitive performance! (7)

For insomnia: Drink it as far away from bed time as possible. The majority of sleep/circadian rhythm experts recommend cutting off your caffeine intake by midday. If you crave coffee after midday, opt for decaf!

For withdrawal: My personal strategy is not to stop drinking it. On a serious note, try to maintain somewhat of a baseline. Your tolerance grows over time and if you continue to increase your baseline because you want to get that ‘same feeling’, you will begin to progressively consume more, to the point that it can become too much (you’re disrupting sleep and consuming quantities that make you anxious). Even if you don’t necessarily get the same feeling as you did when you first started drinking coffee, you’re still getting the health and performance-enhancing benefits!

Wrapping it up

Do the health-promoting and performance-enhancing effects of coffee consumption outweigh the side effects? In my opinion, yes!

You get a significant amount of health promoting chemicals into your body, you feel more alert, focused and driven, and you get an increase in your exercise performance!

There are also ways of approaching your coffee consumption (finding the right dosage, not drinking after midday, pairing with L-theanine and not continually increasing your intake) so that you minimise potential side effects.

References

1. Cappelletti, S., Piacentino, D., Sani, G., & Aromatario, M. (2015). Caffeine: cognitive and physical performance enhancer or psychoactive drug?. Current neuropharmacology, 13(1), 71–88. https://doi.org/10.2174/1570159X13666141210215655

2. Poole, R., Kennedy, O. J., Roderick, P., Fallowfield, J. A., Hayes, P. C., & Parkes, J. (2017). Coffee consumption and health: umbrella review of meta-analyses of multiple health outcomes. BMJ (Clinical research ed.), 359, j5024. https://doi.org/10.1136/bmj.j5024

3. Yashin, A., Yashin, Y., Wang, J. Y., & Nemzer, B. (2013). Antioxidant and Antiradical Activity of Coffee. Antioxidants (Basel, Switzerland), 2(4), 230–245. https://doi.org/10.3390/antiox2040230

4. Grgic, J., Grgic, I., Pickering, C., Schoenfeld, B. J., Bishop, D. J., & Pedisic, Z. (2020). Wake up and smell the coffee: caffeine supplementation and exercise performance-an umbrella review of 21 published meta-analyses. British journal of sports medicine, 54(11), 681–688. https://doi.org/10.1136/bjsports-2018-100278

5. Baltazar-Martins JG, Brito de Souza D, Aguilar M, et alInfographic. The road to the ergogenic effect of caffeine on exercise performanceBritish Journal of Sports Medicine 2020;54:618-619.

6. Bunker ML, McWilliams M. Caffeine content of common beverages. J Am Diet Assoc. 1979 Jan;74(1):28-32. PMID: 762339.

7. Owen GN, Parnell H, De Bruin EA, Rycroft JA. The combined effects of L-theanine and caffeine on cognitive performance and mood. Nutr Neurosci. 2008 Aug;11(4):193-8. doi: 10.1179/147683008X301513. PMID: 18681988.

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