Skip to content
Smart Carbs: Which Energy Products to Choose

Smart Carbs: Which Energy Products to Choose

Figuring out your fuelling strategy before an endurance event is one of the most important things to do to ensure peak performance. Determining how much carbohydrate your body requires every hour is your number one priority. 

After figuring out how many carb grams per hour your body will need, the next question is going to be this:

What is the best way to fuel up with that amount of carbohydrate during my session or event?

There are both logistical and practical considerations to take into account. Let’s take a look at the 4 best-known carb fuelling options for athletes, which are drinks, gels, chews, and bars.

Before comparing the pros and cons of each option, it’s worth noting there is no right or wrong choice, since everyone is different.

Broadly speaking, there isn’t much difference if you consume a drink, bar, chew, or gel. This means it is down to your own practical considerations and preferences, although there are some factors that might make one option better than another.

Does the Carb Formulation Matter?

The sports nutrition industry often puts much of the focus on the type of carbohydrate in energy products and some brands claim one formulation is better than another, thereby boosting your performance.

Whilst different types of carbohydrates can be absorbed and metabolized at different rates, it’s best to focus on how much energy you require and what formats best suit your specific activity before diving into the nuances of the different formulations between products.

Recently there has been plenty of growth in the popularity of using fat (rather than carbs) as the primary energy source. However, the evidence still strongly shows the consumption of adequate carbohydrates is the best solution to maintain endurance.

Energy/Carbohydrate Drinks (‘Isotonic’ Drinks)

Carb-based drinks, also known as isotonic drinks, came out before the other carb-fuelling options and first gained popularity back in the 1970s. They were the best (and only) option to fuel your body with carbs, electrolytes, and fluids while working out. Isotonic drinks are designed to both provide both carbohydrates for energy and fluids to help prevent dehydration and have maintained their popularity over the years.

Nearly all of these isotonic beverages contain about 60 grams of carbohydrate per litre. This 6% carb ratio allows a relatively rapid fluid absorption rate to tackle dehydration while delivering a solid amount of energy at the same time.

These drinks typically contain a small amount of sodium as well to help replace sodium lost via sweating. The basic necessities when working out are water, carbs, and sodium, making energy drinks a good choice.

Advantages of Energy Drinks

  • You can fuel up easily for activities short or medium in duration (say, 30 minutes to 2 hours) when you need a steady stream of energy.
  • There is no chewing or digestion required.
  • With some practice, you can drink even when breathing hard, making them suitable even if your intensity level is very high.
  • They replace some of the sodium and fluids lost via sweating, helping to prevent dehydration.

The above reasons are why carb drinks are so popular with athletes from marathon runners and triathletes to those playing basketball, soccer and many other team sports. These competitors don’t have time to stop mid-event or mid-game to consume a solid type of fuel.

If you struggle to take in calories before a race because of a ‘nervous stomach’ or you just don’t want to eat too many solids, an isotonic drink can be useful to augment the calories from breakfast too.

Disadvantages of Energy Drinks

They may not suitable to meet your body’s needs for electrolyte and fluid replacement if exercising for over 2 hours (or less time in the heat) since the volume of liquids required could cause bloating, nausea, diarrhoea and other GI distress symptoms.

Not everyone likes the sweet flavour and others find they become sickly for the taste buds after drinking a lot of them.

Energy drinks can reduce your fuelling strategy flexibility, so if you need more sodium or fluid but fewer carbs because it’s hot, you can’t get one without the other 2 since an isotonic drink contains all 3 of these.

Energy Gels

Energy gels were first created a decade or so after the first isotonic drinks were launched. Gels were considered a good solution to the issue endurance athletes faced of finding a convenient method to carry and consume digestible concentrated carbs while exercising or training.

Energy gels are space-efficient and lightweight. They deliver a measured dose of carbs, typically between 18 and 30 grams of carbohydrate per serving. Gels haven’t changed a lot over the years in terms of the basic concept, although the packaging and formulations have been tweaked.

Gels are like a cross between isotonic drinks and solid fuel like chews and energy bars. You usually need a drink alongside the gels to wash them down and help with absorption, although some gels now come in isotonic formulas, meaning you can consume them easily without water.

Gels are the most popular method of consuming carbs in many endurance activities.

Advantages of Energy Gels

  • They are highly portable. Rather than carrying a litre of isotonic drink to get 60 grams of carbs, you only need about 100 grams of gels (gels are around 50 grams each).
  • They are handy if you are travelling light or don’t want to carry excessive weight.
  • If your hydration requirements are less than your energy requirements (eg during hard exercise in cold weather) energy gels are useful. If you’re competing in a race in cold conditions, for example, you would need about 30 to 60 grams of carbs every hour but only around 250ml of water. In such a scenario, an isotonic drink would give you only 15 grams of carbs. However, taking an energy gel or 2 would deliver the required carbohydrates without having to over-hydrate to get them.

Disadvantages of Energy Gels

  • Some athletes dislike the sweet taste of gels.
  • Some athletes find they have a sickly taste in their mouth (or flavour fatigue) if they consume too many, which can make them not want to use gels as a sole or main fuel source.
  • Opening the gels can be fiddly during an activity such as biking downhill or kayaking, where you don’t have full use of both hands.

Energy Chews

Chews are similar to energy gels and contain less water. They are very similar to candies or sweets in the way they look and feel. Energy chews are mainly made of simple carbs, like with gels and drinks, and don’t include other macronutrients or fibre.

Chews are energy dense and have an excellent carb to weight ratio. Chews are solid and you have to chew them, hence the name. This can make them a little tricky to consume if you’re exerting yourself and breathing hard. Some chews also have sodium and other electrolytes added.

Energy Chew Advantages

  • Chews can feel more satisfying than gels when working at a low intensity or during a long race since they are more solid in your mouth.
  • They are a good alternative for athletes who don’t like the taste and/or texture of energy gels.

Energy Chew Disadvantages

  • If you are working out at such a high intensity that chewing and swallowing is tricky, energy chews might not be a good choice.
  • If you don’t have full use of both hands, it’s difficult to open the packet.

Chews can be used with gels interchangeably if you like both. They are the best option if weight/energy ratio is a critical consideration.

Energy Bars

These are an example of how sports nutrition can be very similar to ‘real food’. Maybe the biggest difference between energy bars and other sports nutrition products is that bars often contain macronutrients like fibre, fat, and protein, and not just simple carbs.

Some of the first energy bars on the market were very sticky on the teeth and had a bland taste. Modern energy bars have improved in texture and flavour and there are more ‘real food’ ingredients packed into them so they offer a better flavour and are more satisfying to consume.

Energy Bar Advantages

  • Their protein, fibre and fat content make them more satisfying than a drink, chew or gel during a long training session or event.
  • They can double up as a useful snack before or after a workout session if you don’t have access to a good high-carb meal.
  • Energy bars are great in ultra-distance events, when you begin craving something in addition to simple sugars.

Energy Bar Disadvantages

  • Bars are more difficult to chew and swallow if you’re on the move, making them specifically suited to longer distance events where you move at a slow enough pace to eat them. This is why runners don’t choose energy bars as much as cyclists - they’re just easier to eat on a bike than when running at speed.
  • You often need fluid to wash these down, especially bars with a dry texture.


The main focus should be getting sufficient energy on board every hour, adjusting the fuel to suit your preferences and needs.

t’s better to choose a fuel format you like to drink or eat instead of forcing yourself to take products just because others recommend them to you. Everyone is different in terms of requirements and personal preferences.

If you’re still figuring out which format of fuel source suits you most, take time to experiment with each one. You should expect a period of trial and error while figuring out whether drinks, chews, bars, or gels, or a mixture of these, is best suited to your needs.

Also, if you do various types of activities, you might find one format is best for one type of activity while something different works for another.

Ultimately, all the above fuel sources work well and are viable options for athletes to refuel on the go. In addition to your personal preferences, the intensity and duration of your activity can determine which type of fuel(s) to consume for the best results.

Next article High-Carb Fuelling: When to Use It and How