Dextrose

D-glucose (or D-glucose) is the older technical term for glucose. It was coined by Jean-Baptiste André Dumas in 1838. His colleague Friedrich August Kekulé considered the name dextrose (from Latin dexter = right) to be more appropriate, as ordinary dextrose has the physical property of twisting the plane of linearly polarized light to the right. In contrast, levulose turns polarized light to the left.

Simple sugar is an important nutrient

Dextrose is the most common and biologically most important simple sugar. It is a component of household sugar and is found in most fruits and honey.

Dextrose is also known as glucose. This natural sugar is found in many sweet fruits. Dextrose is commercially available and is usually made from potato or corn starch. As a simple sugar, dextrose belongs to the group of carbohydrates which, along with fats and proteins, are the most important nutrients for humans. The proportion of all carbohydrates in the total daily energy intake should be at least 50 percent and should mainly be provided by foods such as

• muesli
• wholemeal bread and
• vegetables

should be covered. These foods belong to the multiple sugar products. Even if sugar intake in the form of desserts is tempting, the ten percent limit should not be exceeded.

Dextrose provides energy

During a performance slump, whether during sport or at work, sugar provides new energy. The advantage of dextrose is that it is immediately absorbed into the bloodstream during digestion because it has the same chemical structure as blood sugar. Dextrose is the fastest-acting energy substance in the human body. But there is also a disadvantage: in order to lower the elevated blood sugar level, our body immediately releases the hormone insulin. As a result, the blood sugar level drops after just 20 to 30 minutes and you feel tired and listless.

Dextrose and mental performance

Although the brain only accounts for 2 % of body weight, it provides 20 % of the body's energy requirements, making it one of the most active organs. It is important to note that under normal conditions the brain uses 100% dextrose as an energy substrate. There is only one exception to this rule, and that is when we are starving. Here the brain also uses other energy substrates from the protein and fat metabolism as a kind of survival mechanism.

Important

Unused dextrose is stored in the form of glycogen in the blood, liver and muscles. If there are sufficient stocks there, the excess glycogen is converted into fat by the liver and is available as a reserve. The fat deposits are mainly located around the lower abdomen and on the thighs. At the same time, LDL cholesterol can appear. The glucose produced during the digestive process enters the blood and triggers the release of insulin, which transports the glucose into the cells. If it does not do this sufficiently, the sugar remains in the blood and is excreted in the urine - diabetes can develop. - 1 g of glucose contains 4 calories.

Carbohydrates in sports

One of the most reliable and inexpensive ways to increase training performance and recovery is to supplement with carbohydrates. Studies have found that carbohydrate intake before and during exercise reliably enhances exercise performance, especially for workouts lasting over 30-45 minutes [1-5]. In addition to reducing fatigue, the use of carbohydrates during exercise also accelerates the rate of recovery by inhibiting proteolysis, especially when protein intake is adequate. [6] . This article discusses how carbohydrates enhance performance, the types of carbohydrates that can be used and the ideal dosing strategy for enhanced performance.

Mechanisms

During exercise, glycogen and plasma glucose are both important sources of energy. Carbohydrate intake keeps blood glucose levels high, providing a steady source of energy for active muscles. This also helps maintain muscle glycogen and prolongs the time it takes to deplete glycogen stores. [1] . Carbohydrates can also improve exercise performance by having a positive effect on the central nervous system. [3-4].

Types of carbohydrates

Dextrose: Dextrose or D glucose is also known as dextrose. It is 70-80% as sweet as sucrose (table sugar). Dextrose is absorbed and consumed quickly, providing a rapid source of energy. Maltodextrin: Maltodextrin refers to dextrose polymers with variable lengths. Unlike dextrose, maltodextrin is not very sweet. Although technically a complex carbohydrate, maltodextrin results in a glycemic response similar to that of dextrose. Dextrose is less expensive, sweeter, and easier to mix.

Fructose: Fructose is the sugar that gives fruit its sweet taste. It is lower on the glycemic index than dextrose and is absorbed more slowly in the intestine and then metabolized in the liver. Most studies on carbohydrates and exercise involve maltodextrin, dextrose or a combination of the two. One concern that has arisen is that ingestion of these carbohydrates causes rebound hypoglycemia and thus decreases exercise performance. This can be solved by consuming carbohydrates before and at regular intervals during exercise - in fact, carbohydrate intake before and during exercise has been found to have an additive benefit compared to only one of the two[3] . Fructose and other low GI sources of carbohydrate are of little value, although the difference is small. Low GI carbohydrates cause more gastrointestinal discomfort and are also absorbed more slowly, limiting the availability of muscle glucose[7].

Ideal amount

During the most intense exercise, the amount of glucose consumed can exceed the maximum rate of absorption [2], so it is important to consume a large amount of carbohydrate for maximum effectiveness. However, if too much is consumed, gastrointestinal discomfort may result. [1] . The literature shows that amounts in excess of 1.5 g per minute certainly do not improve fuel utilization with a small probable benefit of over 1.0-1.1 g per minute [2, 8]. It is also important that the solution is diluted enough for optimal absorption - in the range of 20-40 g of carbohydrate per 480 ml. Based on this information, my carbohydrate recommendations for maximal exercise performance are as follows:

For strength training or short duration exercise (30-60 minutes):

• 2-3 tbsp dextrose (20-30 g) in 360-720 ml water 15-30 minutes before training.
• 3-5 tablespoons of dextrose (30-50 g) in 480-960 ml of water during the entire workout.

For endurance training:

• 3 tbsp dextrose (30 g) in 720 ml water 15-30 minutes before training.
• 3 tbsp dextrose (30 g) in 480 ml water at the start of the workout and then every 30 minutes (note that it is also essential to ensure adequate sodium intake if you are taking in so much fluid).

Note that these are for maximum performance only, and recommendations depend on specific circumstances. A person trying to limit caloric intake, for example, would want to consume less. Also, one may reduce carbohydrate intake accordingly when consuming protein during exercise.

References

1. Eur J Appl Physiol. 2003 Jan;88(4-5):431-7. Epub 2002 Nov 19. Metabolic profile of 4 h cycling in the field with varying amounts of carbohydrate supply. Meyer T, Gabriel HH, Auracher M, Scharhag J, Kindermann W.
2. Am J Physiol Endocrinol Metab. 2002 Sep;283(3):E573-7. plasma glucose kinetics during prolonged exercise in trained humans when fed carbohydrate. Angus DJ, Febbraio MA, Hargreaves M.
3. J Appl Physiol. 2000 Dec;89(6):2220-6. Effects of carbohydrate ingestion before and during exercise on glucose kinetics and performance. Febbraio MA, Chiu A, Angus DJ, Arkinstall MJ, Hawley JA.
4. J Appl Physiol. 2000 Nov;89(5):1690-8. Effect of carbohydrate ingestion on glucose kinetics and muscle metabolism during intense endurance exercise. McConell GK, Canny BJ, Daddo MC, Nance MJ, Snow RJ.
5. Eur J Appl Physiol. 2003 Jan;88(4-5):444-52. Epub 2002 Nov 27. Effects of pre-exercise ingestion of differing amounts of carbohydrate on subsequent metabolism and cycling performance. Jentjens RL, Cale C, Gutch C, Jeukendrup AE.
6. J Physiol. 2000 May 15;525 Pt 1:271-81. Effect of oral glucose on leucine turnover in human subjects at rest and during exercise at two levels of dietary protein. Bowtell JL, Leese GP, Smith K, Watt PW, Nevill A, Rooyackers O, Wagenmakers AJ, Rennie MJ.
7. Eur J Appl Physiol. 2003 Jan;88(4-5):459-65. Epub 2002 Nov 27. Effects of pre-exercise ingestion of trehalose, galactose and glucose on subsequent metabolism and cycling performance. Jentjens RL, Jeukendrup AE. 8 Sports Med. 2000 Jun;29(6):407-24. oxidation of carbohydrate feedings during prolonged exercise: current thoughts, guidelines and directions for future research. Jeukendrup AE, Jentjens R.