Caffeine: friend or foe? A balanced view
It’s thought to be the most commonly used drug on the planet, yes that’s right, it can actually be classified as a drug. In fact people are now more likely to consume caffeine on a daily basis than fruit, with four out of every five people in western cultures using it every day. In 1984 the International Olympic Committee banned it with the restriction only lifted in 2004. It’s currently on WADA’s monitoring list of substances worthy of further research into its use as a performance enhancer in sports, meaning they’re keeping an eye on its use, its effects of athlete health and on its effects on race results, but for now it’s legal. As a known ergogenic aid (meaning a substance that helps improve performance), it is widely used in sports like cycling, but does everyone taking it know why, how it works or the possible risks? Here we’ll review the evidence for using it and if you’re going to, the safest and most effective guidelines.
Does it work?
In short, yes, it appears so. Research suggests that caffeine ingestion improves endurance effort when performed to fatigue or at high intensity, as well as performance during high intensity short-term exercise. In the latter for example, tests lasting approximately 5 minutes, performed at 90 to 100 per cent of maximal oxygen uptake in the laboratory show a significant performance improvement when using caffeine.
What does it do and how?
There are numerous theories for how caffeine may benefit sports performance and at present, that’s just what they are. There’s no definitive proof as of yet as to exactly how caffeine effects your body when exercising, but one of the theories has stuck it’s wheel out as the front runner in recent times. Let’s have a look at this main theory.
It’s thought that taking caffeine delays feelings of fatigue by blocking receptors for a sleep-related neurotransmitter called adenosine. What this means is that you feel less tired and therefore more alert, increasing awareness and perceived energy levels and as a result, boosting performance.
What else might it do?
- Caffeine is thought to have an effect on your metabolism, mobilising your fat stores. This means you use more fat during exercise, sparing carbohydrate stores. This is useful as carbohydrates are the fuel you use for high intensity exercise and with more available you’ll have more energy for that breakaway, hill or sprint finish.
- It may also suppress your awareness of pain, with reduced feelings of discomfort meaning you’re able to work harder before you fatigue.
- By stimulating your central nervous system, nerve impulses, heart rate and blood pressure may be increased meaning faster reactions, increased blood flow and higher adrenaline levels, all of which may enable your cardiovascular system to supply your muscles with more energy and your nerves to better stimulate your muscles, increasing strength and power output.
- It’s also thought that caffeine may help improve cognitive function and that this increased mental awareness can then help race and training performance.
I stress that much of this is theoretical and the research on caffeine is complex, some studies show positive effects whilst others do not. But maybe that’s exactly the point; maybe everyone is different and therefore responds differently to caffeine.
What are the risks?
The fact that caffeine is readily available around the world suggests that it’s safe to consume. There are however some considerations when using it. Large doses of caffeine aren’t believed to offer any greater performance benefits than just using small amounts and may have some negative outcomes such as anxiety, gastrointestinal distress (meaning frequent trips to the toilet), over-arousal leading to fast heart rate and higher blood pressure, jitters and poor sleep patterns. All of these issues may affect you during a race, especially if you haven’t used caffeine in training to test how your body responds.
Recently I cycled to a meeting around 20 miles from my house. I flew there as the weather was nice and I was feeling good. At the meeting my host asked if I’d like a cup of coffee. I don’t really drink it (I’m a tea drinker) but I thought why not, I’ve used it when I’ve been racing or doing long days in the saddle for my charity events and it’s made a difference for me. What I don’t usually do though is drink three cups of the freshly filtered stuff, more often than not it’s a black coffee from Maccy D’s before my day in the saddle. As I began to cycle home I thought, “I feel great” and decided to push on but within a few minutes this high was replaced by an equally strong low. In the end, what had taken me an hour to get there took over double the time getting back, with toilet stops and a break at a local shop to ply myself with sugar as my energy levels had plummeted so that I could barely steer the bike in a straight line. Lesson learned.
Regular use of caffeine has also been linked to arrhythmias (abnormal heart beats) and in my time working in the medical screening world, patients were frequently advised to cut down on caffeine to help manage the missed heart beats they were experiencing.
There are challenges too of course in coming off caffeine. With all of the possible effects on the brain and body, it’s no wonder when people try to remove it from their routine that their body responds. Shaking, anxiety and hunger are common.
One commonly aired concern is of caffeine as a diuretic. Yes it is but in the doses we’ll mention shortly that are effective for improving performance, it shouldn’t be an issue. It was once thought that drinking coffee would dehydrate you but now it’s established that the water content of the coffee seems to outweigh the diuretic effects of the caffeine content.
What are the guidelines for use?
Ok, this is probably your big question so let’s get to it, how much caffeine makes a difference to your performance and when and how should you consume it? So that you know you can trust what you read.
Rather than rely on my word, in this section I’m going to use the International Society for Nutrition’s Position Statement on the use of caffeine for sports performance. Let’s check out each of the points in turn:
- Caffeine is effective for enhancing sport performance in trained athletes when consumed in low-to-moderate dosages (around 3-6 mg/kg). No further enhancement in performance is seen when consumed in higher dosages (greater than 9 mg/kg). So what do these numbers look like in real terms? If you weigh 70kg it means you’ll get benefits from 210-420mg and there’s little point consuming more than 630mg. The following are common source of caffeine with the content listed:
- One medium cup of Costa coffee (Americano or Cappucino) contains 277mg.
- One can of standard Red Bull has 80mg.
- One cup of normal instant coffee contains between 50 and 80mg per cup.
- One Pro Plus tablet has 50mg.
- One cup of traditional strength tea has around 40mg. However, the longer it brews the more caffeine it contains and different teas have differing amounts, with Assam black tea one of the stronger blends having up to 80g per cup.
- 100g of milk chocolate has around 18mg.
2) Caffeine exerts a greater ergogenic effect when consumed in an anhydrous state as compared to coffee. In layman’s terms, it’s stronger when taken without water. It’s thought that this is because the roasting process alters the caffeine’s ability to delay fatigue. This means if you’re using things like Pro Plus or caffeine powders, go easy as you may not need as much as was outlined in point one to have an effect and the risk of side effects increases too.
3) It has been shown that caffeine can enhance vigilance during bouts of extended exhaustive exercise, as well as periods of sustained sleep deprivation. This means you’ll be more alert even when tiring towards the end of training rides, events and races.
4) Caffeine is ergogenic for sustained maximal endurance exercise, and has been shown to be highly effective for time-trial performance.
5) Caffeine supplementation is beneficial for high-intensity exercise, including team sports such as soccer and rugby, both of which are categorized by intermittent activity within a period of prolonged duration. This means it can also have benefits for intermittent efforts during cycling, such as events involving breakaways or hills.
6) Research into the effects of caffeine on strength and power performance varies, some suggests it makes a difference whilst other studies show no effect. It may or may not help maximum power efforts but more research is needed to decide this one way or the other.
7) The scientific literature does not support caffeine-induced diuresis during exercise, or any harmful change in fluid balance that would negatively affect performance. What this means is that taking caffeine in the doses recommended earlier does not appear to have any impact on hydration levels. Obviously you must be hydrated before beginning exercise and maintain fluid levels by taking on fluids as needed for the duration/intensity of your ride.
Elevated levels can appear in the bloodstream within 15-45 minutes of consumption, and peak concentrations are evident one-hour post ingestion. If your effort will be short you therefore need to time intake accordingly. Longer events may require you to ingest caffeine at intervals to ensure you can sustain performance.
Whilst the levels of caffeine mentioned earlier may be considered quite high, some research has shown that even a small amount of caffeine (1-3 mg/kg) can help performance in prolonged exercise and may also be helpful in exercise of shorter duration. You can hit these levels by simply drinking a cup of coffee or a soft drink such as a Coke.
Though everyone responds differently, the amount in one cup of coffee has been shown to aid short-term, intense activities and improve endurance athletes’ times by up to 3 percent, an amount that could indeed make a difference in high-level competition. In fact, it’s equivalent to the effects a marathon runner could expect to see from consuming carbohydrates during the race.
Considerations for use
Finally, let’s consider some of the practicalities of using caffeine so you can make an informed decision about whether or not to use it.
- You are unique – as mentioned above, everyone responds differently so you’ll need to find out what works and doesn’t for you. How does it make you feel? Does it give you any side effects? Do you drink it regularly already? If so, you may be more used to it meaning it has less effect.
- Practice makes perfect. It may take a while to discover the right amount and timings for you. Don’t expect to get it right straight away and always try it on training rides before using in a race.
- Timing is everything. Caffeine works best about an hour before a performance so you’ll need to adjust your intake to suit the event you’re doing.
- Just one piece of the puzzle. Don’t expect to be signed up to Team Sky the moment you start using it. It’s just one thing that you can use to help your performance improve, one of Dave Brailsford’s marginal gains you might say, along with nutrition, hydration, training, recovery, mental approaches and of course the right pillow!
Paul Waters has a BA (Hons) in Sports Studies and an MSc in Exercise and Nutrition Science. He has 15 years experience in the health and fitness industry as a fitness instructor, personal trainer, health and wellbeing physiologist, tutor and writer.
He currently writes and delivers the courses that individuals take to become personal trainers, contributes to a range of magazines and is author of The Complete Guide to Weight Loss by Bloomsbury Publishing. He runs his own business, balance, helping individuals and organisations to improve their health, fitness and wellbeing.
He is a keen cyclist and runner and regularly competes in events or charity challenges. This year he ran the Three Peaks and cycled the 450 miles in between over four days. He is very sensitive to caffeine, in fact it makes him feel dizzy and weak if he consumes too much, so he only uses it when doing long days in the saddle for his charity challenges to take away the pain!