Sports Foods for Acute Use: Drinks, Gels, and Bars

Sports Foods for Acute Use

In module 1 of this course, we defined what we mean by sports foods. To review this concept, we can say that sports foods are made up of the same nutrients as regular foods, essentially: carbohydrates, proteins, and fats. However, sports foods are portable, and their presentation and composition make them very practical. This text will cover sports foods for acute use. That is: foods that immediately provide either a performance, health, or recovery benefit when ingested, such as a sports drink that can be consumed during a 10 km (6.2 miles) street run. It is important to note that sports nutrition products such as sports drinks and recovery protein drinks are not considered supplements (Morton, 2014).

Sports Drinks, Gels, and Bars

Sports Drinks

Sports drinks contain three components: water, carbohydrates, and sodium. Although the most common sports drinks formulations found on the market generally include other substances (such as vitamins, other minerals like potassium or calcium, caffeine, BCAA), solid scientific evidence only supports the effectiveness of the former three components (Coombes and Hamilton, 2000).

Composition of Sports Drinks

Sports drinks are made up of the three components we previously listed. Based on current knowledge, we can say that the ideal composition of a sports drink is as follows:

• 50 to 80 g of carbohydrates per liter.
• From 80 to 350 kilocalories per liter.
• More than one type of carbohydrate, not only glucose.
• Osmolarity between 200 and 400 mOsm/l.
• Between 20 and 60 mmol/l of sodium (460 to 1380 mg/l).

In table 1, we see the composition of different sports drinks that are either currently available, or have been available on the market.

Applications of Sports Drinks

Sports drinks are useful for rehydration, and to provide nutrients in endurance sports, such as road cycling, mountain biking, running and trail running, triathlon, kayak, as well as team sports such as soccer, rugby, hockey, etc., and even during load training.Table 1: Composition of Different Commercially Available Sports Drinks Sports Drink Energy (kcal/I) Sodium Potassium (mg/l) (mg/l) Chloride (mg/l) Osmolarity (mOsm/kg) Total carbohydrates (g/l) Carbohydrate concentration (%) (weight per volume) Sugars (g/l) Vitamins 10K 240 220 120 N/A 350 60 6 N/A N/A Allsport 320 220 220 N/A N/A 84 8.4 10 N/A Endura 248 320 540 N/A N/A 64 6.4 N/A N/A Exceed 280 200 180 320 1000 68 6.8 N/A N/A Gatorade 252 412 120 4 320-360 60 6.0 14 None Gatorade (Europe) 200 440 120 32 378 56 5.6 14 N/A Hydrafuel 264 100 120 N/A N/A 68 6.8 N/A Cand E Isosport 248 452 116 N/A N/A 72 7.2 15 N/A Isostar 280 440 180 32 280 68 6.8 N/A C, E, ß- Carotene Powerade 280 280 120 N/A N/A 76 7.6 15 N/A Sponser N/A 276 440 11 326 64 6.4 N/A N/A Sport Plus 288 364 216 N/A N/A 72 7.2 18 N/A Staminade 204 242 196 N/A N/A 52 5.2 13 N/A Xcel 248 198 280 N/A N/A 60 6.0 N/A N/A Source: prepared by the authors.

Timing of Sports Drink Use

Sports drinks are primarily used for hydration during exercise. In endurance sports, such as running and trail running, mountain or road biking, or a triathlon, the ideal hydration option would be one that allows the athlete to rehydrate whilst simultaneously providing key nutrients (carbohydrates and sodium). In team sports they are also recommended for the same purpose, even during strength training. They may be used before or after training and competitions, but their formulation is ideal for use during exercise.

Australian Institute of Sport Usage Protocol for Sports Drinks

Below are some useful recommendations based on the recommendations of this prestigious institution for the optimization of sports performance. Sports drinks were designed to provide a balanced quantity of carbohydrates and fluids, allowing the athlete to simultaneously rehydrate and recover during exercise. According to expert recommendations, in order to quickly deliver fluids and fuel, and to maximize gastric tolerance and taste, sports drinks must be composed of approximately 4-8% (4-8 g/100 ml) of carbohydrates and 23-69 mg/100 ml (10-30 mmol/l) of sodium (American College of Sports Medicine et al. 2007; American Dietetic Association et al. 2009). For situations that require a fast delivery of recently consumed carbohydrates to the muscle, drinks containing multiple transportable carbohydrates (a mix of carbohydrates such as glucose and fructose that employ different intestinal transporters) are recommended. These may overcome the usual limitation of the intestine to absorb carbohydrates. Studies show that mixes such as these are effective in increasing muscular oxidation of carbohydrates consumed during exercise, compared to products containing only glucose (Jeukendrup, 2010). Electrolyte replacement, sodium in particular, is useful in preventing the sensation of thirst. A sodium concentration of around 10-25 mmol/l improves the palatability and voluntary fluid consumption during exercise. Sports drinks may contain other electrolytes (e.g. magnesium, potassium, and calcium). Current evidence suggests that significant quantities of magnesium are not lost during exercise, and it is therefore unlikely that additional magnesium may favor hydration or reduce cramps. The taste and temperature of sports drinks are also important factors in terms of meeting hydration goals. Studies show that athletes are able to better compensate for sweat loss through fluid consumption when the drinks offered are flavored, rather than with water (Minehan, Riley & Burke, 2002; Maughan & Leiper, 1993). Cold drinks are generally tastier to athletes who are exercising in warmer conditions, or to those who are suffering from the heat associated with high-intensity exercise.Table 2: Recommendations for Carbohydrate Consumption during Sporting Activities. Type of Sport or Exercise Duration Carbohydrate Target or Requirement Comments Brief exercise < 45 minutes Not required. High-intensity sustained exercise 45 to 75 minutes Small amount, including mouth rinse. A number of products and sports drinks can provide rapid uptake carbohydrates Opportunities to consume foods and drinks vary depending on the different rules and nature of each sport. Everyday dietary options and specialized sports products ranging from liquids to solids may be useful. Endurance exercise, within which stop- and-go sports are included 1 to 2.5 hours. 30 to 60 g/h The athlete must practice to find a fuel recovery plan that can satisfy his individual goals, taking into account hydration needs and intestinal comfort. Ultra-endurance events > 2.5 to 3 hours Up to 90 g/h Same as before. Higher carbohydrate intake is associated with better performance. Products that provide different transportable carbohydrates (mixes of glucose and fructose) will reach high oxidation speeds for the carbohydrates consumed during exercise. Source: Burke et al., 2011, p. 5. The composition of sports drinks provides a generic balance between fluid and carbohydrate requirements for several sports. The relationship between fluid and fuel needs may vary depending on the environment, the athlete's nutritional preparation, and the demands of the exercise.

• If the need for fluids is greater than the need for carbohydrates, it is possible to use sports drinks with a lower carbohydrate content, or diluted sports drinks.
• If the need for carbohydrates is greater than the need for fluids, sports drinks with a higher carbohydrate content may be used; supplements such as sports gels, sports bars, or sports snacks may also be used.

Sports Gels

Out of the three primary components for sports drinks, essentially only one is used in sports gels: carbohydrates. In addition to this, they contain a given concentration of sodium, and some gels also include other substances (caffeine or amino acids).

Composition of Sports Gels

As mentioned, their primary component is carbohydrates. A pouch, depending on the commercial brand, provides around 20 - 25 g of carbohydrates. Gels also provide a given amount of sodium, and around 25 mg (single caffeine gel) or 50 mg (double caffeine gel) of caffeine.

Applications of Sports Gels

Their primary application is to allow the athlete to meet the carbohydrate requirements for different kinds of exercises. For instance, a triathlete training for an Ironman trial may include a given amount of gels per hour into his competition plan, allowing them to cover the estimated carbohydrate requirements. To this end, gels may also be included in team sports or other individual sports such as tennis.

Timing of Sports Gel Use

The correct moment for their use is during exercise. Depending on the specific situation, they may be ingested before or after exercise in order to meet target carbohydrate requirements.

Australian Institute of Sport Usage Protocol for Sports Gels

• Source of highly concentrated carbohydrates (65 to 70% or 65 to 75 g/100 ml) in the form of a gel that is easily consumed and quickly digested.
• Substantially higher in carbohydrate concentration than sports drinks, they provide a high fuel increase with a single portion.
• Easy-open pouches allow for their consumption during exercise. They may also be given in small plastic bottles that are easy to squeeze, allowing the athlete to carry several gels. They allow for flexibility in consumption frequency and volume during endurance and ultra-endurance physical activity.
• Different gel products may be distinguished by taste, consistency, type and amount of carbohydrates, as well as by the inclusion of other active ingredients, including caffeine.
• For situations that require a high rate of delivery of recently consumed carbohydrates to the muscle, gels that contain multiple transportable carbohydrates (a mix of carbohydrates such as glucose and fructose that employ different intestinal transporters) may overcome the general intestinal absorption limitation. Studies show that mixes such as these are effective in increasing the muscular oxidation of carbohydrates consumed during exercise, compared to products containing only glucose (Jeukendrup, 2010).
• There is a large variety of sports gel products commercially available. The features that distinguish them are their volume or the content or concentration of carbohydrates, the type of mix of carbohydrates, the consistency or texture of the gel, and the presence of other active ingredients.
• Other active ingredients that may be found in sports gels include electrolytes and caffeine.
• Sports gels provide a compact and portable source of carbohydrates that may be easily consumed, immediately before or after exercise, in order to meet the desired carbohydrate consumption.
• They must be consumed with water or other diluted fluids that may help cover the hydration needs imposed by the activity on their own. Fluid intake will also reduce the net concentration of carbohydrates, reducing the risk of intestinal problems.

Despite recommendations given in sports nutrition guidelines against the consumption of concentrated forms of carbohydrate during exercise, recent studies have shown that gels consumed alongside water during moderate intensity exercise provide a pattern of liberation and oxidation of carbohydrates in the muscle similar to that delivered by sports drinks (Pfeiffer, Stellingwerff, Zaitas & Jeukendrup, 2010).