Caffeine is used by many athletes due to its potential as a performance enhancer. There is a substantial amount of scientific evidence to support this. How you get the caffeine into the body can vary. There are several delivery mechanisms that range from coffee to sports nutrition products, caffeine shots and tablets. There is another delivery mechanism that might be faster: chewing gum. In this blog we will discuss the effects of caffeine in chewing gum.
Caffeine mechanisms of action
In early studies, caffeine was suggested to be ergogenic by increasing fat oxidation and thus sparing muscle glycogen (1). However, it is now known that caffeine stimulates the central nervous system (CNS), and this is the main mechanism for its ergogenic effect. Caffeine does this by binding to adenosine receptors. Adenosine usually works to depress CNS function. However, when you consume caffeine, it blocks adenosine receptors which consequently stimulates CNS function as opposed to depressing it.
Sources of caffeine
There are several different forms by which you can ingest caffeine, including coffee, tablets, gum, powder, bars and energy drinks (eg Red Bull). Whilst all of these forms have performance enhancing effects, there is a delay of at least ~20-30 minutes until they are noticeable and it takes around 60 min for caffeine to reach a peak in the blood. This is because caffeine must be absorbed, pass the liver and enter the circulation before it can affect the CNS.
Early studies into the delivery of caffeine in chewing gum were conducted with a military purpose. The military use caffeine to stay awake, improve alertness, mood and performance. All of these effects are backed by several studies, however the studies also used forms of caffeine whereby it took at least 20-30 min before effects were noticeable. In their search for something faster, it was hypothesized that delivering caffeine in a chewing gum may speed the rate of caffeine delivery to the blood. This would be possible if caffeine was would be absorbed through the buccal mucosa (in the mouth) as well as the gut.
Faster caffeine absorption with gum
It was known from drugs other than caffeine that absorption was more rapid through the buccal cavity. When this occurs, the drug (or in this case, caffeine) bypasses the liver and therefore is not “filtered” out of the blood. Of course, a faster rate of caffeine absorption and thus delivery to the circulation with gum should also lead to faster biological effects.
This was put to the test in a landmark study by Kamimori and colleagues in the United States (2). They measured caffeine concentrations in the blood following the ingestion of capsules or chewing gum. Blood samples were taken over the following 90 minutes to assess the levels of caffeine in the blood. Caffeine appeared faster in the circulation with the gum compared with the capsules. It took 84-120 min to reach a peak with the capsule and only 44-80 min with the gum. When 200 mg of caffeine was ingested, caffeine concentration was much higher 5-15 min and even 15-25 min after ingestion with the gum.
Implications for sport
Although initially the caffeine gum was used in military situations, it soon made its way over to sport. Amongst the literature, doses of 200-300 mg caffeinated gum have been shown to improve cycling time trial performance, maximal cycling efforts and running time to exhaustion. An advantage of using caffeinated gum is that the majority of caffeine bypasses the gut, which may be useful if you suffer from gastrointestinal discomfort.
There is a substantial body of literature demonstrating that caffeine, delivered in any form, can improve various aspects of performance. Most notably perhaps endurance performance, but there are also studies that show effects on power, strength and cognitive performance. For a review read Spriet (3) and a recent meta analysis (4).
When considering caffeinated chewing gum it is essential too consider the exact dose that is required to see and effect and the timing of intake. If the dose and timing is optimised caffeinated gum can be used to improve performance in a wide variety of sports settings. As always it is important to try a new strategy in training first.
References
Graham TE, Spriet LL. Metabolic, catecholamine, and exercise performance responses to various doses of caffeine. J Appl Physiol (1985). 1995 Mar;78(3):867-74. doi: 10.1152/jappl.1995.78.3.867. PMID: 7775331.
Kamimori GH, Karyekar CS, Otterstetter R, Cox DS, Balkin TJ, Belenky GL, Eddington ND. The rate of absorption and relative bioavailability of caffeine administered in chewing gum versus capsules to normal healthy volunteers. Int J Pharm. 234(1-2):159-67, 2002.
Spriet LL. Exercise and sport performance with low doses of caffeine. Sports Med. 44 Suppl 2: S175-84, 2014
Ferreira TT, da Silva JVF, Bueno NB. Effects of caffeine supplementation on muscle endurance, maximum strength, and perceived exertion in adults submitted to strength training: a systematic review and meta-analyses. Crit Rev Food Sci Nutr. 2020
