Just brew it: The effects of caffeine on running performance

Caffeine is the most popular drug consumed worldwide, found naturally in more than 60 plants as well as being found in many common foods and drinks. Over 90% of the US population consumes caffeine on a regular basis, with the most common sources of natural caffeine being in tea and coffee. In fact, 75% of this frequent caffeine consumption has been said to come from coffee, so at least I'm not the only one with a coffee addiction, right? If you're like me and don't feel particularly clued up on caffeine amounts, an average cup of coffee hosts about 95mg of caffeine. The recommended maximum daily intake of caffeine is 400mg for the average adult. Common energy drinks, dependent on their size, can provide anywhere between 85 and 200mg of caffeine per can, showing why we should be wary of over-consuming these products.

Early behavioural effects of ingesting caffeine are things such as increased mental alertness, faster flows of thought, restlessness and reduced levels of fatigue. Alongside this, it can also have effects on our nervous system, hormones, body temperature and endorphins. Considering these stimulating effects, caffeine is a very popular choice to consume pre-workout for many different forms of sporting activities. It is fast absorbing into the blood flow, peaking between 15 to 120 minutes depending on other bodily factors. Regardless of whether drunk, swallowed or eaten, this quick absorption is roughly the same. But, how beneficial is caffeine for your running performance? Are you better off just sticking to good, ol' H20 for a successful session, or is your morning coffee really making the difference?

How does it affect my sporting performance?

In short, caffeine has been found to be effective in sports performance. Consuming caffeine before a session helps to maintain physical performance through reducing our perceived tiredness and increasing our mental concentration. This means the mental and physical fatigue often experienced during a high intensity race or long endurance session can be somewhat combated by the help of caffeine. In terms of the science behind it, caffeine stimulates the release of fatty acids into our blood early on in activity, conserving our glycogen supply. In turn, this enhances our physical working capacity due to the bodies preferred use of fat instead of muscle glycogen, allowing us to perform better for longer. Caffeine consumption prior to exercise has been found to coincide with prolonged time until exhaustion. A study found that 27 out of 30 runners improved their performance in a 5km running test after caffeine ingestion one-hour before the trial. This effect was found to occur for both well-trained and recreational runners. Similarly, this performance enhancing effect from caffeine ingestion has also been found to occur in maximum effort sprint tests.

Not only has caffeine shown to positively influence runners sporting performances, but the running performance in athletes of other sports has also been shown to improve. Footballers who consumed caffeine prior demonstrated an improved running speed during a 7 x 30 meter test, higher distance covered at maximum sprint speed and an increased amount of sprint bouts during a simulated football match. Additionally, their power output during a jump test was also greatly improved.

As mentioned previously, caffeine has effects on our mental state and is capable of decreasing our perceived level of exertion. Most athletes will be familiar with the quote "winning is 90% mental and 10% physical", highlighting further how caffeine can positively impact our performance. Research has suggested this is due to caffeine-induced changes to the chemicals in our brain, leading to an increase in alertness and excitability.

How much caffeine is needed for these positive effects?

Whilst a common question, unfortunately the answer is almost entirely based on personal factors. How much caffeine is optimum depends upon your body and your tolerance levels of caffeine. Too little can mean you won't receive the positive impacts on your performance, however too much can cause adverse side effects such as high blood pressure, fatigue and a rapid heart rate. It is also worth noting that too much caffeine can prolong wakefulness causing disturbances in sleep patterns. In turn, this could have a negative impact upon running performance.

Increases in running performance have been found to be somewhat influenced by the amount of caffeine ingested, with a lower dose sometimes having no effects at all. Although person dependent, a standard cup of coffee is usually a reliable amount of natural caffeine that can provide you with a boost without the sudden crash afterwards. For endurance athletes, another recommendation is sticking to between three to six mg/kg body weight. However, as previously stated, the amount of caffeine that provides these positive effects is entirely personal and so learning your own body is key to avoid negative outcomes. Obviously once reaching competitive level within your sport, rules may apply to how much caffeine is allowed to be consumed prior to an event and these should be followed as directed.

Which kind of caffeine is best to consume?

Scientifically, no difference has been found in relying on a coffee or a caffeinated sports nutrition product pre-race. Having said that, sports nutrition products often provide other important nutrients alongside the caffeine and so considering what else your body may need, fuel wise, is important in making your choice. But, you might be wondering if there is any difference in the types of caffeine found in these products?

Caffeine anhydrous is a processed, dehydrated form of caffeine becoming popular to use in supplements or food products, such as energy bars. Anhydrous simply means "without water". Chemically they are the same, however the dehydration process means caffeine anhydrous is more concentrated. Most often, it is available for consumption in pill or tablet form, or as a soluble powder. Both caffeine forms are said to have equal improvements on athletic performance, with similar positive and negative effects on the body found. Tablets use precise measurements, meaning your intake of caffeine can be more accurately regulated and controlled through this method of ingestion. Although, caffeine anhydrous is more concentrated and must be handled with increased care. Errors in measurement are more possible in powdered form and can lead to adverse effects.

Overall caffeine has been shown mostly to create positive effects on running performance, with ingestion time often being one hour prior to the activity. Amounts of caffeine, and the effects caused, do vary between individuals, therefore learning your own bodily tolerance is important for maximum positive impact. Too much caffeine for your system can cause negative effects, but generally your morning cup of joe should only positively influence your session. Great news for all of us running, coffee lovers out there! Personally, I completely notice the difference if I'm running in the morning and haven't drank a coffee beforehand. My motivation and perseverance always feel heightened as well as an overall increase in energy. Whilst we should never depend on caffeine to get us through, it is definitely an added benefit to my favourite morning pastime.

Do you find coffee has a positive impact on your runs? Let me know what you think down in the comments!