Gels and energy drinks to the competition.

Although I discussed this topic in depth in a chapter of my book Power supply Evolutionary sports, I’m going to summarize here, as it continues to generate questions (I asked a lot about it) and I think that deserves a second look for their importance and complexity. Despite being products widely used, gels and energy drinks continue to be a cause of confusion for many athletes, often without being aware of it.

A gel is not only a gel and as it is; not all are equal in their composition (amount, type, and mix of carbohydrate, the amount of fluid, presence or absence of other components, such as caffeine, electrolytes, etc). Therefore, not all serve the same purpose, they are not taken at the same times, or affect the performance of the same way. In addition, the vast amount of brands and different products of each even more complicated your choice.

The gels and energy drinks are fundamental to the performance in competitions more than an hour. For very full that we begin to glycogen, this will be exhausted if you do not invigorate, negatively affecting performance.

The first thing we do is to see these products as a way to replace what we lose during the competition (water, sodium, and glycogen). Therefore, it will be necessary to calculate the dose of each one depending on the context: the duration of the test, heat/humidity, exercise intensity, and individual capacity of absorption of carbohydrates. The water and the sodium (hydration) have already dedicated a previous article, which I invite you to read to those who have not done so, since both of these articles complement each other.

We’re going with carbohydrates.

Osmolarity and tonicity

To understand all, one must first be clear in two previous concepts:

1. Osmolarity. Is the pressure or osmotic concentration of a solution. A solution is a mixture of particles/molecules (of the solute, such as glucose, electrolytes, etc) dissolved in a fluid (solvent, such as water). The osmolarity measures the concentration (amount or number) of particles (such as sodium or glucose) dissolved in a fluid. The more particles you have with respect to the fluid, the higher the osmolarity, and thicker and more concentrated will be the solution. For example, pure water has an osmolarity essentially zero.
2. Tonicity. Compare the osmolarity (concentration of molecules) between two solutions. When we speak of gels and energy drinks, always compare it with that of blood plasma.

Then, when we say that a gel or drink is:

• Hypertonic: osmolarity is higher than that of the plasma; it has a higher concentration of particulate matter (carbohydrates, sodium, etc) that the blood and less water in proportion.
• Isotonic: osmolarity is the same as, or very similar, to that of the plasma.
• Hypotonic: Has a lower osmolarity, that is to say, less molecules with respect to the liquid.

Why it is important to know this distinction, and what happens in the body after the ingestion of a gel or energy drink with carbohydrates/electrolytes

If the drink or gel is hypertonic

Having a higher osmolarity (less proportion of water molecules that transports), two things happen:

1. The gastric emptying (passage from the stomach to the intestine) is slower, which means that the gel or drink takes longer to reach the intestine, and, from there, to the blood, where it will carry its components (water, sodium, carbohydrates, etc.) to the cells, which is what interests us.
2. Once in the intestine, there will be a transfer of water from the blood into the intestine to balance the concentration of particles (osmolality) between the two fluids and diluting to its absorption. This is not desirable during intense exercise, as this movement of water:
   1. Delayed absorption.
   2. Reduces blood volume (causing dehydration).
   3. Possibly, increases gastrointestinal problems (pain, cramping, diarrhea…).

If the drink or gel is hypotonic

The opposite happens: the gastric emptying is more rapid and, once in the intestine, the water is transferred in the opposite direction (from the gut to the blood) to balance concentrations. This facilitates quicker absorption of the components and accelerates the hydration, reducing the likelihood of gastrointestinal problems. This would be ideal; however, to reduce the osmolarity, we must decrease the amount of carbohydrates, and sodium, which might not help to improve the performance, which is our goal in the competition.

We must find the appropriate balance between: (1) Hydration: to recover the water and sodium that we lost to prevent reduced our performance; and 2) Fuel: eating the highest amount of carbohydrates as possible to enhance the performance, without overcooking, so as not to increase the osmolarity and convert the drink in hypertonic, which would delay the gastric emptying, would lead to dehydration and increase the risk of gastrointestinal problems.

To achieve this, ideally, is a type of isotonic beverage, with the same osmolarity of the blood plasma. In the case of the gel is hypertonic (it will be, if you do not specify that it is isotonic), should be taken with about 250-300 mL of water to make it isotonic and avoid the problems mentioned above.

For reference, a drink is considered to be isotonic when it has between a 7-8 % concentration of glucose (or glucose + fructose). To calculate the concentration of a drink, just look at the label of the product multiply by 100 the amount of carbohydrates indicated and divide the result by the mL of the drink. If you prefer gels (for convenience, as in the case of runners), it is best to choose one isotonic and, if it is not, balance your intake with a refreshment to be able to drink water at the same time.

Any athlete interested in taking the higher amount of carbohydrates as possible during the competition to get that extra intensity. However, if we exceed, increased osmolarity, and we make the drink hypertonic. And we already know that in order to avoid gastrointestinal distress and facilitate gastric emptying and the absorption of nutrients, the osmolarity of the drink/gel should be at least equivalent to that of the blood. Therefore, the increase in carbohydrates in drinks, we have the limitation of 7-8 % of glucose concentration. For example, in 500 mL of water, 8% would be a maximum of 40 g of glucose.

How to increase the amount of carbohydrates and, at the same time, lowering the osmolarity

Here is where comes in the type of carbohydrate and its molecular weight (or size). As we said before, osmolarity measures the number of particles dissolved in a fluid; therefore, the fewer the particles have, the lower the osmolarity.

A solution with the same amount of carbohydrates can have a high osmolarity if it contains many small particles, or an osmolarity low if the particles are few but large. It is like to carry the same merchandise in many small trucks or a few larger ones. So, what we are interested in is that the particles of carbohydrates are as large as possible (higher molecular weight). If the ‘trucks’ are larger, we can transport more goods without increasing the osmolarity (with the same number of trucks) or maintain the same amount of goods with fewer osmolarity (less trucks).

In summary: to higher molecular weight of the carbohydrate, the lower osmolarity of the solution, resulting in a gastric emptying faster (step faster from the stomach to the intestine) and less gastrointestinal problems.

Molecular weights of the carbs

Then, let’s look at the different molecular weights of the carbohydrates are the most common, ordered from lowest to highest:

• Glucose and fructose = 180 g/mol. Are the simpler molecules that can be a carbohydrate. The more complex carbohydrates (polysaccharides), which we will see later, are formed by chains of monosaccharides. The more molecules are bound, the greater the complexity and the molecular weight of the carbohydrate. The body finally breaks down these compounds into monosaccharides, as that is the only way that can be absorbed.
• Palatinosa (isomaltulose) = 342 g/mol. A disaccharide that is the result of the bacterial fermentation of sucrose (glucose and fructose).
• Maltodextrin = 504 g/mol. Polysaccharide composed of 5-10 units of glucose. Usually, it is a product of the hydrolysis of starch from corn, rice or potato.
• Dextrin cyclic highly branched (HBCD, for its acronym in English) = 400 000 g/mol. Also known as cyclodextrin or under the trade name Cluster Dextrin®. Derived from waxy maize, is the product of two enzymatic processes that result in a cluster structure with a molecular weight very high. This makes its osmolarity is minimal (9 mosm/L in a 10% solution) compared with the maltodextrin (117 mosm/L) or glucose (640 mosm/L) in the same proportion. In addition, gastric emptying is more rapid: 25 minutes compared to the 40 of the glucose (study). There are gels that combine this dextrins with maltodextrin to make them isotonic. Other benefits of this dextrin, which include a lower perception of effort compared with the maltodextrin and improvements in the microbiota, because it acts as the fiber is not digestible and prebiotic (study).
• Superstarch® = 500 000-700 000 g/mol. The carbohydrate with higher molecular weight up to date, my favorite, and the one I use with my athletes.

Superstarch

Superstarch is a starch derived from waxy maize, modified hidrotérmicamente (adjusting humidity, temperature and time) and patented by the company with Generation UCAN. Was originally developed to treat a rare disease of children, glycogen storage disease, in which those affected can’t transform the stored glycogen back into glucose and, therefore, need to be given glucose continuously and gradually.

Its use has been extended to the field of sport due to its high molecular weight, which makes its osmolarity is almost nonexistent (it could take virtually no water). This allows you to accelerate to the maximum gastric emptying and minimize gastrointestinal problems. In addition, due to its complexity and molecular weight, Superstarch is semirresistente digestion; it passes through the intestine to the blood and releases glucose slowly.

This process provides two key benefits:

1. Maintains a source of sustained energy and durable, avoiding the ‘roller coaster’ blood sugar (without subidones or low energy).
2. To not cause a spike in glucose, does not stimulate the release of insulin, which allows you to continue using the deposits of fat as fuel and save the stored glycogen, as well as glucose-newly absorbed of Superstarch.

Ratio of glucose/fructose

It has been widely recognized that combining monosaccharides (glucose and fructose) is more efficient than using only glucose. The reason is that you do not share the same transporters. Both nutrients, after the gastric emptying, reach the small intestine and are absorbed (pass from the gut to the blood) in order to follow its course. This absorption is limited by the capacity of their transporters, implying that in-competition is not we can eat all the carbohydrates we wanted without the risk of gastrointestinal problems. The glucose used a transporter-dependent sodium (SGLT-1), which saturates to a certain amount, but the fructose using a separate transporter of sodium (GLUT5). To combine them, we increased the capacity of absorption of carbohydrates per hour.

The debate now is not whether to use only glucose or both monosaccharides, but what is the ideal ratio of glucose/fructose.

Until recently, it was assumed that the ratio ideal was to 1/0,5 (i.e., the dual of glucose and fructose). However, recent research suggests that a proportion close to equal (1/0,8) is more efficient compared with a ratio lower (1/0,5) or higher (1/1,25) (study). With this ratio increased in fructose, you get a more efficient use of carbohydrates ingested (approximately 20%) and a greater saving of carbohydrates endogenous (stored glycogen).

Another benefit of increasing the fructose is that this goes directly to the liver to replenish the glycogen. Unlike what was previously thought, is the decrease in hepatic glycogen (and not muscle), which causes fatigue and limits the performance (study). For the brain, is not as concerned about the decline of muscle glycogen as the liver, which is their source of fuel. When the brain detects that the hepatic glycogen decreased during physical activity, and this involves the blood glucose levels, we ‘indicates,’ fatigue and increases our rate of perceived exertion. Fructose, by going directly to the liver, helps to reduce the feeling of fatigue, which in the end is what limits us in maintaining the intensity.

However, consider that fructose has a molecular weight very low (equal to that of glucose), which increases the osmolarity. This effect can be compensated by combining it with carbohydrates of higher molecular weight, as the Superstarch or the cyclodextrin. In addition, as fructose is slower absorption, not quickly raises the blood glucose or stimulates the release of insulin, and perfectly complements the Superstarch to take advantage of the fat as a source of energy.

Why you should never include potassium and magnesium

Potassium

Although most of the brands include potassium in their product (and we get paid), it is not necessary to take it during the competition or lengthy training. We know that potassium is inside the cell, unlike sodium, which is on the outside. If invigorate sodium during the activity, there is no need for potassium to leave the cell to balance the levels of sodium, potassium, and therefore do not lose it. In other words, if we maintain the level of sodium, no need to replenish potassium.

Magnesium

Nor is it necessary to replenish magnesium during the competition. Despite popular belief, the magnesium is lost during exercise. However, it is crucial to continually maintain their blood levels in the optimal range. As with any nutrient, magnesium is important for everyone, and even more so for athletes. In addition to its known role in the prevention of cramps, magnesium helps to calm the muscles (heart included), the nerves and the brain. It is also a necessary cofactor for the functioning of some 300 enzymes.

Why not recommend gels and energy drinks in long runs of low intensity

In long workouts (over 2 hours) and hot, if the intensity is low or moderate, I don’t often recommend include carbohydrates, only water and sodium to maintain hydration and blood volume. Many athletes, during long print runs to pace a low-to-moderate, consume gels or drinks with carbohydrates, which I believe is an error. If you use gels or drinks with carbohydrates, the body prioritizes the glucose that reaches the blood as fuel, leaving you use (or using a lesser extent) the stored fat. So, you lose a good opportunity to improve metabolic flexibility, training in the use of fat as a source of energy, and become more efficient in their metabolism, which is essential to be an athlete more complete. The only exception for using these products would be to try a day in order to assess your tolerance before a major competition.

If the intensity is low to moderate, we do not need carbohydrates in order to complete the training. If we notice that we need, that indicates a problem of metabolic flexibility: we are not able to use the fat as fuel and, therefore, we must train more, this way reducing the glycogen. The sensations during the process of improvement will not be good, but as with everything, if you don’t train this ability, you’ll never improve. We have fat reserves that we can and should be used as fuel; entrenémoslas to take advantage of them.

Summary

• Hydration and loss of blood volume (water and soda): In long-term activities, it is essential to replenish water and sodium to prevent the loss of volume and the consequent decline in performance. The need for both increased when you train or compete in hot environments, as the sweat increases their loss. If the competition or training lasts less than 1 hour and a half, leaving it well hydrated and replenish at the end is usually enough. For more details, you can refer to this previous article.
• Carbohydrates: Higher the molecular weight, the better, and should be used only when the intensity and duration of the activity is required. If the competition or intense training lasts less than 1 hour and have deposits of glycogen-filled (as it should be), it will not be necessary to replenish carbohydrates, since it does not give us time to exhaustion. If the intensity is moderate (zone 2-3, below the second anaerobic threshold), it shall not be necessary to eat carbohydrates, even if glycogen stores are low; our fat reserves will be sufficient as a fuel. In addition, this is a good opportunity to improve metabolic flexibility and efficiency in the metabolization of fats. On the contrary, if the intensity is high (zone 4 or more) and the activity lasts more than 1 hour, replenish carbohydrates is essential to maximize performance. In addition, by taking them with sodium, it facilitates the absorption of the latter.
• Ratio of glucose/fructose: it Is recommended to use a drink or gel with a ratio of glucose/fructose 1/0,8. This relationship helps to oxidize more efficiently carbohydrates ingested and to best preserve glycogen stores, ‘reassuring’ to the brain with the arrival of fructose to the liver to reduce the feeling of fatigue. It should be noted that ‘glucose’ does not refer to pure glucose, but any carbohydrate of high molecular weight that is broken down into glucose.
• Potassium and magnesium: are Not required specifically during the competition or strenuous activity, but it is important to maintain adequate levels of these nutrients in the blood through a balanced diet and supplementation, if necessary, to correct a deficit.