Is caffeine an effective performance enhancer for the squash player?

Caffeine is found in a variety of plants, foods, and beverages, and is widely used the world overestimates suggest that 4 out of 5 people in Western cultures consume some source of caffeine every day.

Whilst caffeine is known primarily as a stimulant drug, it also has a number of other potential actions within the body.

It is particularly useful for sportspeople and those wishing to lose weight due to the effects it has on our metabolism, brain, and central nervous system, and is, in fact, one of the most potent (legal) performance enhancers for athletes – estimates suggest anything up to 60% of competitive athletes have used it to boost competitive performance, with performance-enhancing effects having been demonstrated in both longer duration endurance and shorter-term high-intensity efforts.

Despite this, for a lot of people caffeine has a rather negative reputation. People talk of its potential anxiety/insomnia related side-effects, its alleged dehydrating effects, and of its addictive nature.

Caution should certainly be exerted by those with high blood pressure, or with any kind of cardiac impairment – advice should always be sought from a doctor before supplementing with caffeine if you suffer from any medical conditions related to either of these areas.

Beyond this however, most side-effect issues are dependent very much on the individual user, and are often rather over-blown – the reported dehydrating effects, for example, have been shown to be based on flawed evidence. As regards issues of addictiveness, some regular caffeine consumers have been known to develop a mild physical dependence, and experience negative moods and headaches if suddenly withdrawn. It is not a ‘true’ addiction such as with drugs/nicotine/alcohol however, and most ‘sufferers’ are comfortably back to normal within a couple of days of ceasing use.

Some people do report anxiety issues and difficulty sleeping after caffeine use, but this is often more to do with dosage and timing – consuming caffeine in the two or three hours before you go to bed is probably not a good idea, for example (caffeine actually has a relatively short half-life however, and around 50% of it will have been eliminated from your body within 4-5 hours).

In terms of dosage, different people will have different needs/tolerances – research suggests lower levels can be effective, with most people being on the continuum of needing between 1 to 3 milligrams of caffeine per kilogram of bodyweight to feel some mental and physical boost, up to around 5mg/kg for more pronounced performance enhancement effects.

Even at the upper end, this will only be around 350-400mg of caffeine in a daily dosage for the average person – still under half of the level theorized to have any possible negative health effects. For elite level athletes, Sports Nutritionists have actually suggested intakes of as high as 5-10mg per kilo of bodyweight for one-off events/competitions, though this probably wouldn’t be advisable on a regular basis.

Drug-tested athletes should also be aware that some governing bodies do test for abnormal levels of caffeine – this would usually be at an equivalency level of around 10mg per kg of bodyweight however. In part because of its potentially extremely potent effects, there is some debate over whether there should be stricter controls on the use of caffeine in sport.

So what are the actual specific effects of caffeine, and how does it work?

Caffeine acts in the body through several theorized mechanisms, but the most significant influence is its effect to counteract a substance called ‘adenosine’ that we have circulating in high levels in our body.

Adenosine acts in the brain to suppress activity in the central nervous system, so by acting on this substance caffeine reduces this suppression whilst increasing excitation and activity in neurotransmitters (this short video outlines the process well). In respect to physical activity, this can have the effect of boosting focus, enhancing general body coordination, lowering our perceived exertion (how hard an activity feels), and even potentially dampening exercise-induced muscle pain.

Even more relevant to the athlete, is the suggestion that caffeine may help boost endurance by increasing fat utilization and decreasing glycogen utilization (our bodies contain far more fat than glycogen).

This effect of increasing fat oxidation and sparing muscle glycogen, allows us to work harder for longer. This is also obviously of great benefit to those training for fat-loss goals, and for this reason, caffeine is also a common ingredient in many ‘fat-burner’ supplements.

One interesting preliminary study from 2008 also showed that large volumes of caffeine ingested with post-workout recovery beverages actually increased muscle energy store replenishment – more research is needed to establish exactly the lowest dosage this will occur at is, but it’s interesting nonetheless.

In addition to all this, there is even some promising research that suggests regular caffeine intake may play a role in reducing the risk of certain cancers, liver disease, Parkinsons Disease, and Diabetes (Type 2).

So for squash players, it’s well worth considering giving caffeine a go-ahead of your next session, to help kick-start your energy levels and reduce feelings of fatigue. This link has an excellent database of the caffeine contents of various beverages, but the two most common ones are still coffee and commercial energy drinks (such as Red Bull) – be aware however of the high added sugar content of many of these caffeine-based energy drinks. Caffeine tablets are often a quicker and more convenient way to ingest caffeine, particularly if you don’t enjoy the strong taste of the aforementioned beverages or wish to avoid the extra calories – it’s worth noting though, that coffee may actually confer a number of additional health benefits.

For best results experiment with intake timings of between 20-60 mins before exercise, and try and eliminate extraneous caffeine from your daily routine to ensure you really feel the full effects of your pre-exercise boost (although some recent research has suggested that habitual daily intake may not, in fact, impact the performance-enhancing effects of acute caffeine supplementation after all).

For those interested in some further reading there’s a good article on caffeine and athletic performance here. For a more comprehensive review of some of the main scientific literature regarding caffeine and performance, check out both the International Society of Sports Nutrition’s position stand on caffeine and this extremely in-depth Examine.com feature.

Gary Nisbet

B.Sc.(Hons), CSCS, NSCA-CPT, Dip. FTST 
SquashSkills Fitness & Performance Director