If you are new to running, or only started recently, you may have heard of energy gels, but have no idea what they are or how to use them. Or you may be wondering whether you should be using one of the many sports energy drinks on the market. Don’t worry, read on to find out all you need to know.

Energy Gels

Semi-liquid gels provide you with a source of energy in a packet. Just tear open and swallow while running. Taking gels helps to replace your carbohydrate stores, known as glycogen, which you use to create energy as you run. Gels help to maintain your energy levels and enable you to run for longer, but should only be used when you will be running for an hour or more.

This is because your muscles store enough glycogen to fuel your running up to this point. The main ingredient in a gel will be carbohydrate. This could be either the simple sugars glucose and fructose, or maltodextrin, a starch manufactured from glucose. Most gels contain a combination of carbohydrate types. This is because glucose and fructose are carried into your bloodstream by different biochemical mechanisms. Studies have shown that you cannot absorb more than 60g of glucose per hour, but adding fructose increases total sugar absorption to around 90g, enabling more energy to be created.

Gels also contain some water, electrolyte minerals such as sodium and potassium, and flavouring and preservative. They may also contain caffeine, as this has been shown to have benefits for performance. Some gels are more diluted and easier to swallow than others. Most gels need to be washed down with water or they may not be absorbed into your bloodstream quickly enough. However, some brands can be swallowed without water. Always check the label and make sure you stay well hydrated as you run. It’s best to experiment with several different brands to see which you prefer, and practise your fuelling strategy well before race day.

You can consume up to 30g of glucose or maltodextrin or up to 45g of glucose-fructose mix per half hour of running. That’s equivalent to two to three gels per hour, depending on the brand’s formulation. Read the label or check out the brand’s website to find out the recommended amount to use. It’s best not to wait until you have been running for an hour before taking your first gel as, while quickly absorbed, the effect isn’t instant. Try your first gel 30-40 minutes into your run and experiment to work out how often you need to take a gel during long runs. Not everyone gets on with gels, with some people experiencing stomach cramps, tummy upsets or nausea when they try them. This may be because they have difficulty tolerating fructose, in which case it’s worth trying a brand that contains only glucose or maltodextrin.

Or they may have problems with the caffeine in some gels, or simply have a sensitive stomach. Never try a new gel on race day!


Energy drinks provide an alternative to gels when you’re running for an hour or more. For shorter runs, stick to water or low-calorie electrolyte drinks, because staying hydrated is your priority. Like gels, energy drinks help to replace glycogen stores and their primary ingredient will be carbohydrate, together with electrolyte minerals. But energy drinks have the added bonus of giving you the water and carbohydrate you need in one product.

It’s important to choose an energy drink that has been specially formulated for sport, with a concentration of six to nine grams of carbohydrate per 100g of fluid. This will be shown on the label. Drinks such as fruit juice or highly caffeinated ‘energy’ products such as Red Bull are too highly concentrated for use during exercise. They take longer to empty from your stomach and may cause discomfort, as well as failing to refuel you as quickly as sports drinks. Fruit juice may work for you if it’s well diluted.

Sports drinks come ready-mixed in a 500ml or 750ml bottle, or as a powder that you mix into water and carry in a drinking bottle. You can usually choose from tubs or sachets of powder. It may be easier to use a sachet to start with, to ensure you are using the correct amount of powder. This will vary by brand, but it is generally recommended that you mix one sachet into 400-500ml of water. Aim to drink at least 500ml of energy drink per hour, more on a hot day. It is better to take several sips at regular intervals than to take on large amounts of fluid at once, as this may cause tummy problems. If you know a particular energy drink will be available at your race, practise using it in training to make sure you can tolerate it.

Words by Jo Scott-Dalgleish