Going the distance with sports drinks

To supplement their tough training regimen, today's athletes are looking for sports drinks that enable them to improve their fuel utilisation and overall performance, says Dr Antje Jungclaus of BENEO-Institute

Carbohydrate supplements with an appropriate composition and administration can potentially offer significantly improved endurance performance

Today’s athletes, as well as active people, are eager to learn more about the different types of drinks that are available and that can help to improve their fuel utilisation and overall performance. To supplement their tough training regimen, they are looking for sports drinks that give them the energy to go even further in their sport.

For these sportspeople, it is essential to supplement their training with the right nutrition before, during and after their exercise (to increase their well-being). Carbohydrates are central to sports and exercise performance. According to modern dietary guidelines, an average person should obtain about 55–60% of their daily energy from carbohydrates, which is equivalent to 8g per kg of body weight.1 Athletes rely on carbohydrates because they provide the essential source of energy for physical performance — glucose. In cases of endurance exercise lasting more than 1 hour, sports drinks with 6–8% carbohydrate should be consumed in amounts of 800 mL per hour.

”Slow release” carbohydrates such as Palatinose (isomaltulose) deliver a balanced release of energy for a longer period of time

Most popular sports drinks contain high glycaemic carbohydrates such as maltodextrin, glucose syrup and sucrose. They release glucose into the bloodstream at a fast rate, aiming to maximise carbohydrate utilisation. Consumed before sports, these drinks can result in large spikes and drops in blood glucose levels — not an ideal situation for athletes at the start of a race or event — and the valuable contribution that fat utilisation can add to the fuel mix is suppressed to a great extent.

“Slow release” carbohydrates such as Palatinose (isomaltulose), which deliver a balanced release of energy for a longer period of time, are an interesting alternative. Based on scientific research, Palatinose has been shown to have a sustained effect on normal blood glucose levels compared with other fully digestible carbohydrates. But how exactly can low glycaemic carbohydrates, such as Palatinose, help athletes to go the distance without the sugar crash?

Taking a deeper look

Carbohydrates are undoubtedly important in sports. To understand the science behind it, the relative importance of carbohydrate and fat oxidation to fuel active muscles during exercise and the influence of additional carbohydrate intake need to be considered. A recent meta-analysis concluded that carbohydrate supplements with an appropriate composition and administration can potentially offer significantly improved endurance performance.2

Exercise involves powering muscles with energy from carbohydrates that have been mobilised from the body’s own sources (glycogen) or fat from fat reserves. Particularly during intense exercise, the preferred substrate for energy conversion is carbohydrate because it supplies energy more efficiently. However, the glycogen stored in muscles and the liver is limited to about 1750 kcal.

Particularly during intense exercise, the preferred substrate for energy conversion is carbohydrate

During prolonged endurance exercise at high intensity levels, these stores get depleted and are then no longer sufficient to support the required performance levels. In contrast, body stores of fat are large (around 80,000 kcal), but the conversion of these into energy is much slower than that of carbohydrates. Theoretically, based just on carbohydrate stores, the average athlete exercising at approximately 75% of his maximum oxygen uptake (75% VO2 max) could last only about 80–100 minutes before glycogen depletion occurs, followed by a drop in performance. However, in practice, athletes are capable of much longer endurance events, such as marathons. The challenge is to use the body’s fat reserves to a greater extent to fuel the muscles.

Palatinose acts by increasing the fat burning rate or the proportion of overall energy production that comes from fat oxidation

What role can the choice of carbohydrate in sports drinks play in this? There are two aspects to consider. First, carbohydrates consumed with foods or sports drinks are initially used to supply energy to the muscles, simply because this allows the body to save its own carbohydrate and fat reserves for times when no “external” sources are available. Secondly, the rate of glucose supply from those drinks determines the extent to which the mobilisation and utilisation of internal sources are suppressed. This means that carbohydrates providing fast glucose to the body lead to a more extensive suppression of fat utilization. And here, the advantages of Palatinose become evident: this “slow release” carbohydrate, which provides its energy more steadily for a longer period of time, allows the body to maintain a higher level of fat utilization in the fuel mix to the muscles. In endurance exercise, a higher contribution of fat oxidation is said to have a glycogen sparing effect and thus a beneficial effect that enhances endurance performance.

Breaking down carbohydrates

A study at Freiburg University investigated the impact of different carbohydrates on exercise performance.3 It looked at how the differences in fat oxidation during exercise could influence endurance performance as a result of delayed glycogen depletion in trained athletes. Athletes started by consuming a carbohydrate drink before an endurance exercise. This exercise period was followed by a time trial test to assess endurance performance. On one day, the athletes consumed a drink with maltodextrin; on another day, the same athletes consumed a drink with Palatinose (crossover study design).

The results showed that the participants demonstrated a sustained blood glucose response and lower insulin levels, leading to higher fat oxidation rates during the endurance exercise, after consuming the drink with Palatinose. Moreover, the athletes were able to perform at least equally well, if not better, with the Palatinose drink compared with the maltodextrin drink.

Participants demonstrated higher fat oxidation rates during endurance exercise, after consuming the drink with Palatinose

Boosting fat oxidation may also be important for those wishing to maintain a healthy body weight and body composition. According to the World Health Organization (WHO), obesity is a major issue in European countries with obesity rates running at approximately 62% for the UK, 58% for Spain, 54% for Germany and 49% for Italy.

Various studies have established that Palatinose increases the proportion of energy derived from fat in overall energy consumption.4–8 This applies both to athletes and to those leading less physically active lives. Although the energy balance (the ratio of calorie intake to calorie expenditure) is important, Palatinose does not increase the basal metabolic rate; that is, the amount of energy expended when a body is at rest. Palatinose acts by increasing the fat burning rate or the proportion of overall energy production that comes from fat oxidation. An increased fat burning rate means that active consumers can draw on their carbohydrate reserves for longer and, at the same time, burn fat more effectively.

The results indicate that Palatinose can play a decisive role in weight management. While playing sport or taking part in exercise, athletes can derive a dual benefit from the functional carbohydrate: energy in the form of glucose is available for a longer period during endurance sports, and a greater proportion of energy can be released from body fat. This prevents the total depletion of carbohydrate reserves, enhances endurance and contributes to an athlete’s performance when active.

A natural option for the keen sportsperson

Palatinose is derived from pure beet sugar and is also found in honey and sugar cane as a natural component. Mildly sweet, its sensory profile is very similar to sugar and it has no aftertaste. At the same time, sports drinks produced with Palatinose maintain a constant osmolality, even in acidic and pasteurised beverages, no matter if they are isotonic, hypotonic or hypertonic. This means that the amount of solute particles of salt, minerals or protein remains stable during the entire shelf-life of the product. With Palatinose, new and modern sports drink concepts are possible, providing prolonged energy with a mild and natural sweetness.

Sports drinks produced with Palatinose maintain a constant osmolality, even in acidic and pasteurised beverages

In addition to intense training, maintaining their diets and preparing their minds for the next competition, endurance athletes can benefit from sports drinks that are more specifically targeted to their needs and thus have the potential to further boost their performance levels. However, their importance and key benefits lie beyond what’s in the bottle. Learning more about the ingredients that go into the drink can help them to make informed decisions and choose the sports drink that will truly help them to go the distance.

References

1. American College of Sports Medicine (ACSM), American Dietetic Association (ADA), Dieticians of Canada (DC) Nutrition and Athletic Performance, “American College of Sports Medicine Position Stand: Nutrition and Athletic Performance,” Med. Sci. Sports Exerc. 41(3), 709–731 (2009).

2. T.J. Vandenbogaerde and W.G. Hopkins, “Effects of Acute Carbohydrate Supplementation on Endurance Performance: A Meta-Analysis”, Sports Med. 41(9), 773–792 (2011).

3. BENEO Study: Unpublished Report (2008).

4. BENEO Study: Unpublished Report (2008).

5. BENEO Study: Unpublished Report (2006).

6. H. Arai, et al., “Effects of a Palatinose-Based Liquid Diet (Inslow) on Glycemic Control and the Second-Meal Effect in Healthy Men”, Metabolism 56, 115–121 (2007).

7. BENEO Study: Unpublished Report (2010).

8. D. König, et al., “Postprandial Substrate Use in Overweight Subjects with the Metabolic Syndrome After Isomaltulose (Palatinose) Ingestion,” Nutrition 28, 651–656 (2012).

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