The low-down on Energy Gels
by Ian Craig


Energy gels have swept the market place by force in the past couple of years. It is almost a new ‘buzz’ word amongst runners, cyclists, triathletes and they are even making their way into outdoor shops.

Gels can be viewed almost as a super-concentrated sports drink, squashed into a little packet. The basic ingredients are simply sugar, salt and water. Many companies add colours, flavours and sweeteners. The better products may contain some protein powder or amino acids such as l-glutamine and maybe some vitamins and minerals and more health-based brands have ventured into the use of natural ingredients. 

Because of the recent explosion of the gel market place, there is now a huge selection of energy gels available. Caffeine-enriched gels are very popular: however, be careful if you are sensitive to the effects of caffeine and only use them during races and occasional training sessions because regular stimulant use can increase the likelihood of adrenal burnout and overtraining. On the health side of energy gels, I have even tried a fruit puree product that reminded me of a homemade strawberry jam with some added beetroot pulp – it was delicious and if all energy gels were as healthy and tasty, I would be a definite convert! 

What it doesn’t say on the label

Energy gels have adopted the reputation of being convenient because they can simply be shoved into your pocket, ready to be squeezed into your mouth at an opportune moment. What mostly is not said, however, is the simple fact that they need to be consumed with water. A large bolus of concentrated sugar appearing in your stomach can cause panic to your poor digestive system. What other food item in nature would we eat in such a concentrated-sugar supply? Honey, I hear you say: in contrast to refined sugar, honey, if eating in its raw form, still contains a lot of micronutrients that will help it to be broken down and utilised by the body. Plus, we don’t tend to eat tablespoons of honey whilst running a marathon or hiking in the hills. What can happen to some people who consume an energy gel without water is that the stomach can cramp, obviously somewhat hindering sporting performance. Additionally, the body is very good at achieving equilibrium in its body tissues: because the energy gel is so much more concentrated in sugar than the contents of the blood and plasma, the body can relocate fluid from the periphery of the body to the stomach: in essence, this is causing dehydration of the tissues in the body – the opposite effect of what you are trying to achieve when fuelling on the run.

This scenario certainly applies to the gels that are based on sucrose, glucose or corn syrups, the ones that are very sweet to taste. You do get other gels that may be marketed as ‘slow-released’ or ‘low-GI’, within which the main ingredient is maltodextrin (a glucose polymer). They are slower-releasing than pure glucose and won’t taste so sweet, but they are still very high GI, just not as high as glucose. With these gels, which tend to be the more expensive options, you have the luxury of not needing to take water at exactly the same time. However, during an endurance activity, it is extremely necessary to maintain levels of hydration, so you still need to drink and I would suggest still combining gel and water consumption at the same time. 

How to use gels

How much water should you consume with your gel? If we take the sports drink model, which has been well studied, a 6 to 8 per cent sugar solution is advised to maximise stomach emptying rate, absorption of sugars and hydration status. This means 60-80g of sugar per litre of water. Therefore, if for example a gel is 20g of carbohydrate (read the label for exact amounts), we will need about 1/3 litre of water to gain the same sugar concentration. A 1/3 litre is a lot of water to take in one go, so you could choose to take half gel portions on a more frequent basis. This is the downside to gels: how do we know how much water is 1/3 litre and how do we carry it and where do we get it when outdoors. For this reason, it is much easier to just mix up a sports drink at home and carry it with you. What’s lovely about gels though, is their compactness: if you’re running and don’t want to carry a drink, you can stash a gel in your pouch and source water from a mountain stream, fountain in a park or a shop on-route. 

If you choose one of the gels that’s based on slow-release sugars, it’s not so important to take the water at exactly the same time as the gel, but it is very good practice to think about achieving the same ratios of sugar-to-water; i.e. 1/3 litre water per 20g of sugar. 

With regards to how much and how often, it depends on your activity. If you’re doing something very energetic like hard running or cycling, you can aim for the equivalent of 60g sugar per hour, which is about as much sugar as you can absorb under these circumstances. If on the other hand, you’re spending the day in the hills, you should aim to get the majority of your fuel from solid food, which is digested well at low exercise intensities. The slow-release ‘healthy option’ gels can be used to increase your snack variety, but they do not offer the performance-enhancing effects noticed in high-intensity sports and are therefore not a necessary part of your food repertoire. 


If you were to ask me if I thought that energy gels were a necessary product within sporting and outdoor pursuits, I would say ‘no’. If you were to ask me if energy gels were useful within certain pursuits, I would say ‘maybe’. If, on the other hand, you were to ask me if I thought energy gels provided another interesting method of getting quality nutrition on-board during activity, I would say ‘yes’, providing that is, all of the ingredients listed on the product are from a real food source.