Eating for Endurance – Making Sense of Sport drinks, Bars, and Gels
Are you planning to participate in a long hike, bike ride, swim meet or soccer tournament? These types of long duration events and multi-event competitions require careful consideration of dietary strategies so that you are as energized at the end of your event as you were at the beginning.
A number of factors can cause athletes to experience fatigue from participating in endurance events, and most of these factors can be related to nutrition. Dehydration from sweat loss, hypoglycemia (low glucose energy levels in the blood), and lack of physical energy (depleted muscle glycogen-energy stores) are three common reasons why athletes feel fatigued throughout endurance events. Specific nutrition strategies practiced before and during physical activities may help reduce exercise fatigue.
Nutrition Before Exercise
Plan to consume a low-fat meal plus at least 500 ml of fluid, 2 to 3 hours before your event begins. A light, carbohydrate-rich snack with 250-500 ml of fluid consumed 1 to 1 ½ hrs before an event will help to top up energy (blood glucose) and help with hydration.
Fresh fruit, low-fat muffin, toast, bagel, cereal, yogurt, high carbohydrate sports bar, unsweetened juice, sport drink, water.
Throughout Endurance Events and Multi-event Competitions
Athletes whose physical activities take 60 minutes or longer to complete will benefit from consuming between 30 to 60 grams of carbohydrates for every hour of sustained activity to maintain energy levels, or up to 90 grams of carbohydrates for well-trained ultra endurance athletes, competing /training longer than 2.5-3 hours.
Each of the following foods provide approximately 30 grams of carbohydrate: 1 banana, 3 Fig Newtons, 1 small bagel, 1 piece of fruit, 4-6 crackers, 1 high carbohydrate sport bar, 500 ml of commercial carbohydrate electrolyte drink, 1 sport gel.
It's best to consume some of this food every 15 to 20 minutes. For example, eat 1/3 of a banana every 20 minutes, or eat small amounts when there's a break in the action, such as during the half-time of a soccer game.
Athletes also require fluids throughout endurance events to avoid dehydration. Sweat rates can be highly variable ranging from 0.3 to 2.4 litres lost during an hour of activity. High intensity exercise, hot and/or humid conditions will cause greater sweat losses. As a starting point an athlete should consume at least 400 to 800 ml of fluid for every hour of activity, best consumed in small amounts every 15 to 20 minutes. It is important to note that prepubescent children rarely exceed 400 ml of sweat lost per hour of activity.
Sport drinks – Where do they fit?
A sport drink is much more than a sugary beverage – technically it's a carbohydrate-rich electrolyte (i.e., sodium, potassium) solution designed to supply energy, electrolytes, and fluids lost from physical activity, supporting optimal absorption/fluid absorption. Sport drinks can be consumed before activities to "top up" energy levels, during sustained activities to maintain energy and hydration, as well as after exercise to rehydrate and re-energize. If an athlete prefers sport drinks over water, this may lead to greater fluid consumption.
Sport drinks – What to look for?
Ideally, a sport drink should range from 6 to 8% carbohydrate (i.e., 6 to 8 grams of carbohydrate in every 100 ml of beverage); drinks containing greater than 8% carbohydrate may lead to stomach upset. The primary form of the carbohydrate should be glucose, sucrose, or maltodextrin with some fructose. Since sodium is the main electrolyte lost in sweat, replacing high levels of sweat loss with only water can lead to a severe condition called hyponatremia (low sodium levels), with symptoms of muscle cramps, nausea, vomiting, confusion, disorientation, and possibly bloating (fluid retention). Every litre of a sport drink should contain between 500-700 mg of sodium and 80-200 mg of potassium. There is insufficient evidence to recommend sport drinks containing protein or amino acids. Furthermore, it is not uncommon for athletes to experience stomach upset from such products.
Individuals with fructose malabsorption or FODMAP intolerance should be aware of the fructose content of sports gels containing multiple transportable carbohydrates.
To reduce the chance of dental erosion with the regular use of sports drinks, follow the below tips:
- Minimize the contact time with teeth via holding or swishing in the mouth, use a straw or squeeze bottle to limit contact time with the teeth.
- When practical, consume dairy products or chew sugar free gum immediately after consumption of the sports drink.
- Avoid brushing teeth for at least 30 minutes after consuming sport drinks to allow tooth enamel to harden.
Sport Gels – Are they Suitable?
Some endurance athletes may choose to consume a sport gel for energy rather than a sport drink or other food during activities. However, it's important to drink ample plain water with a sport gel to avoid stomach upset. Most sport gels contain 25 to 30 grams of carbohydrates, but lack sufficient electrolytes to match sweat loss. Some gels may also contain additional ingredients such as caffeine, vitamins, etc., that serve little purpose and may not be desirable for all athletes.
Sport Bars – So many options
The multitude of available sport bars can be divided into three categories: (1) high carbohydrate with low protein, (2) lower carbohydrate with moderate protein, and (3) high carbohydrate with high protein (refer to box). Throughout endurance events or during multi-event competitions, sport bars with high carbohydrate and low protein content are best suited since the carbohydrates are needed for energy and the lower protein content makes these bars easy to digest.
Sport Bar Classifications
|High Carbs, Low Protein||Low Carbs, Moderate Protein||High Carbs, High Protein|
|> 25 grams |
|< 25 grams |
|> 25 grams |
|< 14 grams |
|14-21 grams |
|> 21 grams |
Through careful planning, athletes can limit their exercise fatigue by eating well before their physical event(s), and by consuming ample fluids, carbohydrates, and electrolytes during or in between their activities. Some initial "trial and error" dietary strategies would be advised in low-key competitions or during training to determine the optimal food and fluid choices best tolerated for each athlete.