Do I need to use energy gels?

Registered nutritionist Rob Hobson guides you through the principles of mid-run fuelling


by Rob Hobson |

Most of us appreciate the importance of "carb-loading" in the days before a long race but, of course, you can only store so much glycogen in your body. This amount typically won't be enough for a whole marathon or an ultra, so you'll need to refuel along the way.

The amount and timing of carbohydrate intake should be planned carefully and is individual to you.

Pre-event, there are a number of considerations to help optimise your fuel stores. For events lasting more than 90 minutes, athletes should be looking to increase carbs 36-48 hours beforehand to the tune of 10-12g/kg body weight per 24hr. Before any event lasting 60-90 minutes, athletes should consume 1-4g carb/kg body eight opting for low glycemic-index carbs and avoiding high fat, protein and fibre meals to reduce gastro-intestinal (GI) upset.

Now comes the bit people seem to know less about and that is how to fuel during an event and this is where energy gels can play a useful role.

Events lasting less than 45 minutes have no need for additional carbs so, if this is you, then you don’t need to take these supplements.

Events lasting up to 75 mins may require small amounts of additional carbs which may be better gleaned from sports drink and oral rinses (commonly used in team sports such as football and rugby).

If your event is lasting between 1 and 2.5 hours (this would include both sprint and olympic triathlon, marathon, etc.) then it is recommended that you ingest 30-60g per hour of carbohydrate and you should start refuelling 20 minutes into your event.

In some cases, a sports drink (6g carb per 100ml) may be more convenient but gels may also work for some. Gels are a good choice if you are running as they are easier to keep on you than a bottle of sports drink and you can easily monitor how much carb you are taking in. Look for one that contains a 2:1 ratio of glucose to fructose as this has been shown to enhance carbohydrate oxidation, gut comfort and performance relative to glucose alone.

Gels differ and you must test them beforehand. Energy gels are quite dense and need to be chased down with water. Isotonic energy gels are thinner in texture and maybe easier to consume during a race but should probably still be taken with water. Some gels also contain caffeine and/or electrolytes which can help to pep you up and hydrate.

GI issues are very common during endurance events and your tolerance to carbohydrates can play a key role, so you may want to explore this before you start racing. Make sure you try different brands of gels and you may even want to test with different brands of bottled water (effect of different electrolytes - especially important when racing abroad). Also beware of how much carb you are consuming to reduce the risk of such stomach problems.

Author Rob Hobson is a registered nutritionist with Healthspan Elite

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