Sports gels

• Sports gels are a highly concentrated source of carbohydrate (65–70% or 65–75 g/100 ml) in a form (“honey consistency”) that is easily consumed and quickly digested. Sports gels provide a compact and portable source of carbohydrate which can easily be consumed immediately before or during exercise to contribute to carbohydrate intake targets.
• Carbohydrates consumed during exercise can support or enhance performance via two different mechanisms: provision of fuel for the muscle and a mouth sensing benefit to the brain and central nervous system (CNS). Guidelines for carbohydrate intake during different sporting activities vary according to the importance of these effects.
• There may be other roles for carbohydrate support during prolonged strenuous exercise that are of benefit to athlete health, particularly for high performance athletes. These roles are based on studies that investigate the acute response to exercise; further work is needed to determine if these actions translate into a reduced risk of illness and injury.
  • Consuming carbohydrate before, during and/or after prolonged intensive exercise may help to protect immune function by being associated with a reduction in the detrimental changes in cytokines and immune system cells normally induced by exercise stress.¹
  • Such intake may also be beneficial to bone health by reducing the effect of exercise with low carbohydrate availability on markers of bone resorption.²
• Many gels also contain electrolytes, particularly sodium, to assist with thirst drive and fluid retention, or to contribute to sodium balance during ultra-endurance events (see Electrolyte replacement fact sheet).

• A sachet of a typical sports gel provides:
  • 20-30 g carbohydrate
  • ~350-500 kJ (80-120 kcal)
• While sodium content is typically low (< 100 mg per gel), some brands contain higher amounts (up to 300 mg).
• Some gels contain caffeine (25-100 mg) and as such, may be strategically used to simultaneously achieve specified carbohydrate & caffeine intake goals (see Caffeine fact sheet for details).
• Some gets contain menthol (0.01-0.7%) and as such, may be strategically used to simultaneously achieve specified carbohydrate & menthol intake goals (see Menthol fact sheet for details).
• The type and quantity of carbohydrates provided in gels varies according to the brand.
  • Some gels contain “multiple transportable carbohydrates” — a blend of carbohydrates such as glucose and fructose which are absorbed from the intestine via different transporter molecules (see below).
• Gels are substantially more concentrated in carbohydrate than sports drinks to provide a large fuel boost in a single serve. The majority should be consumed with water or other dilute fluids, which can separately address hydration needs for the activity and reduce the net carbohydrate concentration to reduce risk of gut upsets. A small number of specifically labelled “isotonic” gels are formulated to be consumed without water.
• Despite recommendations in early sports nutrition guidelines against consuming concentrated forms of carbohydrate during exercise, recent studies have shown that sports gels consumed with water during moderate intensity exercise provide a similar pattern of carbohydrate delivery and oxidation by the muscle as sports drinks and are well tolerated by most athletes.^3,4
• Although each gel provides ~ 20–30 g of carbohydrate, decanting into custom made flasks allows the gel to be consumed in more variable volumes. In some sports, a gel can also be added to a drink bottle of water during the event to create a more dilute “sports drink”.
• The consistency of sports gels is likely to increase the amount of time and mouth contact associated with the intake of carbohydrate compared with sports drinks. This may increase the ability of gels to provide a performance benefit via the stimulatory effect of carbohydrate sensing mouth receptors on the brain and central nervous system.

• Use pre-exercise: sports gels provide a low fibre and compact carbohydrate source for pre-event fuelling for athletes who are unable to tolerate regular foods and fluids.
• Use during exercise: to supply carbohydrate to the muscle and CNS.
• Use post-exercise: can contribute to refuelling goals but other foods/sports products should be considered to allow a more nutrient-dense approach to total recovery needs.
  • Fuelling: supplies easily consumed carbohydrates to provide an additional fuel source for the muscle according to the requirements of each sporting activity. Performance benefits have been clearly demonstrated in a range of sporting events as a result of this strategy.^5,6 See Table 1 for guidelines.
  • Mouth sensing: the exposure of receptors in the mouth/oral cavity to carbohydrate creates a favourable response in the brain and CNS, decreasing the perception of effort.⁷

Table 1: Guidelines for carbohydrate intake during sporting activities ⁸

• Delivery of carbohydrate consumed during exercise to the muscle is largely influenced by the rate at which it can be absorbed in the small intestine. Typically, ingesting glucose based carbohydrates (e.g. sucrose, glucose polymers, maltodextrin) at rates in excess of ~ 60 g/h during exercise does not lead to additional performance benefits. In fact, because intestinal glucose transporters (called SGLT1) are saturated at this level, excessive carbohydrate intake can cause gut discomfort/problems that impair performance.
  • The gut can be ‘trained’ by consuming carbohydrates during exercise to maximise the number and activity of the SCGT1 transporters, thus enhancing glucose uptake and reducing gut symptoms.^9,10
  • In addition, some newer sports foods contain ‘multiple transportable carbohydrates’ - a blend of carbohydrates such as glucose and fructose which are absorbed via different transporter molecules in the intestine to overcome the usual bottleneck on a single transport system.
  • Studies have shown that when carbohydrates are consumed at high rates (> 60 g/h) during exercise to meet new guidelines for prolonged strenuous events, drinks containing multiple transportable carbohydrates are more effective than glucose-based products in maintaining gut comfort, promoting muscle carbohydrate oxidation and enhancing performance.¹¹

Unnecessary expense

Sports Gels are not needed at every training session and may be an unnecessary expense.

Unnecessary energy intake

Athletes need to consider their physique goals and total nutritional goals when deciding whether to consume sports gels. In the case of athletes who have short- or long-term restrictions on dietary energy intake, overuse of energy-dense sports foods such as sports gels may create problems with energy balance and overall nutrient density of the diet.

Dental erosion

• Repeated exposure of the teeth to sticky forms of carbohydrate is not ideal for dental health. To help reduce the potential impact of sports gels on dental health, athletes should consider the follow options when they are practical or able to be balanced with the sports nutrition plan.
• Minimise the contact time between the teeth and the sports gel and rinse out the mouth with water once the gel has been consumed.
• Where practical, consume dairy products immediate after the session, or chew sugar free gum immediately after consumption of the sports gel.
• Avoid brushing teeth for at least 30 minutes after consuming sports gels to allow tooth enamel to re- harden.¹²

Gut discomfort

• Athletes should practice the use of gels and assess tolerance during training sessions if they are intended for use during competition. Research in laboratories and in the field has shown that the use of sports gels is well tolerated by most athletes. However, a small number of athletes suffer from significant gastrointestinal issues and may need an individualised protocol ^3,4. The following strategies can help to minimise problems.
  • Sports gels should be consumed with adequate fluid to meet hydration needs and to improve gastrointestinal tolerance.
  • ‘Gut training’ – deliberately consuming a gradually increasing volume and concentration of sports gels during workouts - can allow the gut to develop better capacity to absorb carbohydrate and feel comfortable.
  • The use of sports gels with multiple transportable carbohydrates may assist in maximising gastrointestinal comfort, particularly when carbohydrate is consumed at high rates of intake (> 60 g/h).
• Individuals with fructose malabsorption or FODMAP intolerance should be aware of the fructose content of sports gels containing multiple transportable carbohydrates.

Interference with opportunities for training adaptation

Some athletes may periodise their carbohydrate intake to help support training adaptations. This may include the prescription of workouts in which there is “low carbohydrate availability” (i.e. the session is undertaken with low muscle glycogen stores and/or after an overnight fast). This strategy may increase some of the important adaptive responses to exercise. Therefore, on some occasions, an athlete may deliberately choose not to consume gels or other forms of carbohydrate during the first part of a session.^13,14

Sports Dietitians Australia  www.sportsdietitians.com.au/factsheets, opens in a new tab

Supplement safety information www.sportintegrity.gov.au/what-we-do/anti-doping/supplements-sport, opens in a new tab

1. Peake JM, Neubauer O, Walsh NP, Simpson RJ. (2017). Recovery of the immune system after exercise. J Appl Physiol, 122(5), 1077-1087.
2. Sale C, Varley I, Jones TW, James RM, Tang JC, Fraser WD, Greeves JP. (2015). Effect of carbohydrate feeding on the bone metabolic response to running. J Appl Physiol, 119(7), 824-30.
3. Pfeiffer B, Cotterill A, Grathwohl D, Stellingwerff T, Jeukendrup AE. (2009). The effect of carbohydrate gels on gastrointestinal tolerance during a 16-km run. Int J Sport Nutr Exerc Metab, 19(5), 485-503.
4. Pfeiffer B, Stellingwerff T, Zaltas E, Jeukendrup AE. (2010). CHO oxidation from a CHO gel compared with a drink during exercise. Med Sci Sports Exerc, 42(11), 2038-45.
5. Phillips SM, Sproule J, Turner AP. (2011). Carbohydrate ingestion during team games exercise: current knowledge and areas for future investigation. Sports Med, 41(7), 559-85.
6. Stellingwerff T, Cox GR. (2014). Systematic review: Carbohydrate supplementation on exercise performance or capacity of varying durations. Appl Physiol Nutr Metab, 39(9), 998-1011.
7. Burke LM, Maughan RJ. (2015). The Governor has a sweet tooth - mouth sensing of nutrients to enhance sports performance. Eur J Sport Sci, 15(1), 29-40.
8. Burke LM, Hawley JA, Wong SH, Jeukendrup AE. (2011). Carbohydrates for training and competition. J Sports Sci, 8, 1-11.
9. Costa RJS, Miall A, Khoo A, Rauch C, Snipe R, Camões-Costa V, Gibson P. (2017). Gut- training: the impact of two weeks repetitive gut-challenge during exercise on gastrointestinal status, glucose availability, fuel kinetics, and running performance. Appl Physiol Nutr Metab, 42(5), 547-557.
10. Miall A, Khoo A, Rauch C, Snipe RMJ, Camões-Costa VL, Gibson PR, Costa RJS. (2018). Two weeks of repetitive gut- challenge reduce exerciseassociated gastrointestinal symptoms and malabsorption. Scand J Med Sci Sports, 28(2), 630-640.
11. Jeukendrup AE. (2010). Carbohydrate and exercise performance: the role of multiple transportable carbohydrates. Curr Opin Clin Nutr Metab Care, 13(4), 452-457.
12. Needleman I, Ashley P, Fairbrother T, Fine P, Gallagher J, Kings D, Maugha RJ, Melin AK, Naylor M. (2018). Nutrition and oral health in sport: time for action. Br J Sports Med, 52(23), 1483-1484.
13. Impey SG, Hearris MA, Hammond KM, Bartlett JD, Louis J, Close GL, Morton JP. (2018). Fuel for the Work Required: A Theoretical Framework for Carbohydrate Periodization and the Glycogen Threshold Hypothesis. Sports Med, 48(5), 1031-1048.
14. Burke LM, Hawley JA, Jeukendrup A, Morton JP, Stellingwerff T, Maughan RJ. (2018). Toward a Common Understanding of Diet-Exercise Strategies to Manipulate Fuel Availability for Training and Competition Preparation in Endurance Sport. Int J Sport Nutr Exerc Metab. 28(5), 451-463.