Caffeine Gum Explained by Gloucester Rugby's Dr James Hudson

Author: Dr James Hudson performance nutritionist at Gloucester Rugby in the English Premiership, Performance Champion with Vitality Group and former professional rugby player.

It’s there under your desk, neatly packed and ready to go…the kit bag. Inside is the uniform of the everyday athlete and with the laptop closed, you are ready for your dose of the best drug going. Exercise, it’s the best prescription for both physical and mental health. 

But on occasions when it’s been a long workday, you might be on the search for a little boost, for help when it’s time to get to the gym, tick off a running session or join a social team sport with your mates. Looking for that boost in the form of caffeine is perfectly natural. It is one of the few proven ingredients to give you a few more reps when you’re under the weights bar, finish that last set of HIIT training or just allow that long run to feel easier 1. When deciding how to get your caffeine fix though, my advice would definitely be to chew it over…

Chewing BLOCKHEAD Energy gum, which contains caffeine, can lead to far quicker increases in the level of caffeine circulating in our bodies compared to other forms. Our mouths, or buccal cavity as it is also known, are blessed with incredibly extensive networks of blood vessels. This network together with the saliva we produce when chewing, enables the absorption of a great number of nutrients (including caffeine).

This absorption in the mouth bypasses the usual ‘first pass metabolism’ occurring in the gut and liver possibly even increasing the extent some nutrients can be absorbed overall 2. A significant amount of caffeine is absorbed and goes into our blood by chewing caffeine gum in as little as 5 minutes! When people consumed the same amount of caffeine as either gum or as capsules, the blood caffeine levels peaked in the gum users at 20 minutes after starting to chew vs. 60 minutes after swallowing the capsules3.

This delayed response is true of other forms too. If we guzzle down a caffeine drink or ‘shot’ the effect is by no means immediate. Caffeine is absorbed in the stomach and continues through the gut and this delivery can be further delayed when you are doing high-intensity exercise as there is less blood flowing to the gut, again slowing the time to feel the full effects. Therefore, the benefit of drinking your caffeine may not be appreciated until the later stages of your workout and then may even peak when you are warming down - which is not the aim!

So, if your current habit is to stop off on the way to grab one of the many brightly coloured canned beverages available, promising to either adorn you with the limbs to take flight, or release the animal from within, you may be missing the target. Don’t be fooled if you are still sipping on your ‘pre-workout’ on the gym floor.

The ease to also consume a potentially unwanted high dose of sugar from these drinks may lead some to choose that black elixir of productivity, coffee, as an alternative. However, the reason I wouldn’t recommend this is you are really entering into the unknown as research has shown the content of high street outlets to range massively from 25-214mg in a single drink! 4. Which brings us to the question of how much we really need to gain a benefit?

The latest research delves into what is the minimum effective dose when doing weight training and reveals it isn’t as much as we might think. If we base recommendations on our body weight, somewhere around 1-2mg of caffeine per kilogram (kg) of body weight is enough to significantly improve muscle strength, speed and endurance. Putting this into context for a 70kg individual, 70-140mg is easily covered with 2 pieces of Blockhead energy gum. There is no need for the excessive 250+mg found in many ‘pre-workout’ dietary supplements or the 160+mg found in large cans adorning the walls of convenience store fridges and supermarket shelves!

This is also an important consideration when choosing your ‘weapon’ as a lower total effective dose coupled with a quicker delivery from caffeine gum means the amount in your system is lower and is reducing sooner, and potentially not going to affect other aspects of life. Sleep and nutrition form the foundation of recovery from exercise, and it is crucial we consider both before and after we train. How many times have you had the ‘pre-workout’ or the ‘energy in a can’ only to be lying awake when you should be asleep or experiencing unwanted anxiety when your day should be winding down?

These two key factors for the application of caffeine is exactly the same for everyday athletes as in elite sport. The total caffeine and the timing of any dose. I utilise caffeine gum with the athletes I am fortunate to get to work with as part of their total dose around a matchday. Now, the science tells us that when events are longer lasting such as 90+ minutes of football running at high speeds, or the physically gruelling 80+ minutes of rugby match play, a higher total dose somewhere around 3-4mg/kg (approx. 300-400mg for an average elite rugby union player) is most effective.

Approximately half of this can be in the form of capsules or a shot drunk 45-60mins before kick-off, then to ensure levels don’t drop into the second half the use of caffeine gum is suitable at half time to make up the total dose. The 10-15 minute break to reassess tactics and get some fuel onboard is the perfect opportunity to lift caffeine levels again and quickly, utilising gum.

Many athletes I work with also don’t enjoy the higher single doses which can lead them to feel jittery and unnecessarily anxious, not what we want on a matchday! The gum again plays the perfect part in a smaller, acute dose which can be used 5-10 minutes before kick-off, and again at half time if the player feels they need that boost to sharpen up. It’s not only team sports though, endurance events can last several hours so the opportunity to quickly gain benefit utilising caffeine gum at a key time or in the latter stages of a triathlon, marathon, or cycling event can be crucial in maintaining pace and driving through the pain to the finish line or the top of a big climb.

Overall, caffeine has performance enhancing effects which can be harnessed whether you are an everyday athlete, weekend warrior, or elite performer in many sporting arenas. The trick is knowing and practising your weapon of choice and how it can be effective for training, competition and the period of recovery afterwards. The minimum effective dose should be employed and crucially the timing to make the most of the positive effects. BLOCKHEAD Energy gum is a flexible tool for performance offering a rapid, simple and effective way to deploy caffeine and eliminate unwanted side effects.


  1. Guest NS, VanDusseldorp TA, Nelson MT, et al. International society of sports nutrition position stand: caffeine and exercise performance. J Int Soc Sports Nutr 2021; 18(1): 1.
  2. Shargel L, Yu A. Applied biopharmaceutics and pharmacokinetics. Appletonand Lange 1999: 119-20.
  3. Kamimori GH, Karyekar CS, Otterstetter R, et al. The rate of absorption and relative bioavailability of caffeine administered in chewing gum versus capsules to normal healthy volunteers. Int J Pharm 2002; 234(1-2): 159-67.
  4. Desbrow B, Hughes R, Leveritt M, Scheelings P. An examination of consumer exposure to caffeine from retail coffee outlets. Food Chem Toxicol 2007; 45(9): 1588-92.