Let’s be clear, most people eat too much sugar. But if you are an endurance athlete, your body needs carbohydrate, which ultimately breaks down to sugar. Your body needs sugar during long duration exercise to perform at its best. When it comes to performance, the key is to consume the right type of carbohydrate, at the right times and in the right amounts. Not all carbohydrates and sugars are equal, but neither are individual needs, and cyclists often need a mix of sugars that will be different to someone who doesn't train.
WHAT IS SUGAR?
The word sugar automatically creates visions of sugar coated sweets, lolly pops and coloured sprinkles. The other images that may come to a cyclists mind with regard to sugar are carbohydrate gels, chews and sports drinks. Sugar is everywhere, and for those of us following a largely sedentary lifestyle it is easy to eat too much. In a country where around 2/3 of the population are overweight, sugar is rarely seen in a positive light, but for endurance athletes there are benefits.
Carbohydrates are made up of chains of various sugar molecules. These chains are broken down in the body to release individual sugars, which can be used as an effective fuel by the muscles and brain. Sugar is not always nasty, and can be a valuable energy source for optimal human performance. Different types of individual sugars can be used by the body, and the right balance can be beneficial for providing the best fuel to sustain endurance efforts. Although it sounds like I am talking up the benefits of sugar, there is a time and a place for different types. Some athletes may need to tailor their carbohydrate intake around training and competition in light of other nutrition goals, while others with elevated fuel needs and revved up metabolisms may need regular carbohydrate throughout the day.
HOW MUCH SUGAR FOR ATHLETES?
If you are an athlete that burns a lot of carbohydrate, then sugar will help to fuel performance. But just because you train a lot, doesn't mean you need to carbohydrate load for every training session. Every athlete has different requirements for carbohydrate and sugars based on a range of factors including gender, body weight, body composition, training program, training phase, health status, altitude and genetics. A cyclist’s daily carbohydrate needs can be estimated based on body weight and current training, and this can be adjusted over time to accommodate other individual factors as just listed.
For exercise less than one hour duration, carbohydrate fuel requirements may be low, but there is evidence for performance benefits of a small amounts of carbohydrate during exercise due to potential central nervous system effects. As the duration of exercise increases, so too does the requirement for carbohydrate, with 60-90g/hour recommended for athletes during endurance activity (or even higher for some ultra-endurance athletes working at a high intensity, up toward 110g/hour). For Tour de France riders they would be trying to maximize carbohydrate intake, however there are challenges when working at higher intensities and particularly when you consider mountain stages where energy expenditure is high and opportunity to eat/drink is reduced. Research on multi-stage cycling events indicates that some athletes consume <30g/hour, others a lot higher and over 100g/hour, so there is wide individual variation and also differences depending on the stage and weather conditions. For multi-stage events such as this, carbohydrate intake off the road becomes critical, but often impossible to completely meet daily requirements.
I recently attended a nutrition for ultra-endurance sports symposium run by Monash University and there seems to be a wide range of carbohydrate intakes during competition and different types of training sessions. As you may expect, many individuals find it physically difficult to consume 90g/hour during exercise, and may struggle at even half of this (45g/hour). This is often due to gastrointestinal symptoms, which can be related to individual factors and the type of activity. It is usually easier to eat and drink riding a bike compared to running, but as mentioned it can depend on intensity and conditions. Some people also may simply use carbohydrate more effectively than others. If you are a serious cyclist, it may be worth seeking a laboratory that can test your individual ability to oxidise carbohydrate and to help you work out the best type and amount of carbohydrate for during exercise.
In summary, endurance athletes require sugar for optimal performance, however the right amount will depend on a variety of factors including the duration of exercise, gender, body weight, body composition, training program, training phase, health status, altitude and genetics. Advice from an Accredited Sport Dietician will help you get it right.
In Part 2 of this series on sugar for cycling, I’ll discuss the different types of sugars and combinations that may be beneficial for athletic performance.
Jeukendrup, A (2011) 'Nutrition for endurance sports: marathon, triathlon, and road cycling' JSpSci
Stellingwerff, T & Cox, G (2014) 'Systematic review: carbohydrate supplementation on exercise performance or capacity of varying durations' ApplPhysNutrMetab
Pfeiffer B, Stellingwerff T, Hodgson AB, Randell R, Pöttgen K, Res P, Jeukendrup AE (2012) ‘Nutritional intake and gastrointestinal problems during competitive endurance events’ Med Sci Sports Exerc
Lisa Middleton is one of Australia’s most experienced Sports Dietitians. Lisa has spent over 15 years advising some of the nation’s most elite athletes and teams across a range of sports including VIS athletes, the Essendon, Hawthorn and St Kilda AFL Football clubs, Melbourne Vixens Netball, Melbourne Storm Rugby League and Melbourne Victory Football clubs throughout grand final and premiership years.