Why shouldn't you mix Hammer refresh with other systems?
When an athlete asks us for nutritional advice, we often tell them to use Hammer Nutrition's energy products as a unified system if possible. This means that alongside HEED, Hammer Gel, Perpetuem, or other Hammer energy sources, they should not randomly consume sugary sports drinks, fructose-containing gels, gummy bears, energy jellies, honey, or cola during training and competition.
At first glance, this recommendation might seem too strict. Many people think that all carbohydrates provide energy, so a few sips of cola or a gel from another manufacturer can hardly make much difference. However, in the stomach, all consumed drinks and food become a single mixed blend. From the digestive system's perspective, there is no separate Hammer drink, separate gel, and separate cola consumed at a refreshment station. Only the total amount of fluid, carbohydrates, and calories ingested during a given period exists.
This is precisely why the effect of mixing is not always immediately felt. It may happen that everything is fine in the first few hours, but later, a feeling of fullness, bloating, nausea, energy fluctuations, or diarrhea occurs. In such cases, we often blame the product that we originally carefully measured, while the composition of the entire nutritional system has changed on the fly.
Every manufacturer develops its products based on its own nutritional logic
A sports nutrition product can be examined in isolation, but in practical use, it rarely stands alone. An athlete might drink a sports drink, consume a gel, electrolytes, a bar, and some food in the same hour. These must together form a digestible amount and appropriate concentration.
Manufacturers use different approaches. Some systems are built on high hourly carbohydrate intake and a combination of glucose and fructose sources. Other products use simple sugars, maltodextrin, and multiple types of carbohydrates within a single formula. Hammer Nutrition's own nutritional philosophy is based on more moderate energy intake, consistently dosed fluids, separately controllable electrolyte replacement, and energy primarily derived from maltodextrin.
Each approach must be understood together with its associated dosage. If elements from different systems are randomly mixed, it is easy to lose the proportion according to which the individual products were designed to be used.
This is not exclusively true for Hammer Nutrition products. In a well-designed nutritional system, the energy source, fluid, electrolytes, and dosage are interconnected. However, in the case of Hammer, consistency is particularly important because the system consciously avoids energy supply based on simple sugars.
What does it mean that Hammer uses complex carbohydrates?
The primary carbohydrate source in Hammer Nutrition's energy products is maltodextrin. This is a carbohydrate chain consisting of multiple linked glucose units, and therefore, based on its structure, it is considered a complex carbohydrate, or more precisely, a glucose polymer. For this reason, the manufacturer distinguishes it from glucose, fructose, and sucrose, which are referred to as simple sugars.
One of maltodextrin's special properties is that it can provide quickly accessible energy while supporting a sustained and steady energy supply over a longer period with proper dosing. It consists of longer, linked glucose units that the body efficiently breaks down and utilizes.
Its more sustained effect cannot simply be explained by slow digestion. The breakdown of digestible maltodextrin is rapid, and the glucose released from it can become available for energy production in a short time. This is one of its most important sports nutrition advantages: there is no long wait for the body to utilize it.
According to the manufacturer's approach, the longer carbohydrate chains and lower dextrose equivalent of the tapioca-derived maltodextrin used by Hammer support a more consistent, longer-lasting energy supply. In this, the favorable osmotic properties of maltodextrin, the amount of energy that can be consumed at once, moderate dosing, and continuous use during sports all play a role.
Due to the longer molecular chains, the same amount of carbohydrate can consist of fewer separate particles in the solution than when using free glucose or fructose molecules. This allows a drink made from maltodextrin to provide a significant amount of energy with a more favorable solution concentration when properly prepared.
Therefore, "quickly accessible" and "longer-lasting" energy are not mutually exclusive. The former expresses that the body can quickly utilize the glucose released from maltodextrin. The latter refers to the fact that with a properly chosen amount and continuous dosing, a more consistent energy supply can be maintained.
Why do we not recommend adding simple sugars?
The Hammer Nutrition fueling system is based on maltodextrin being the primary carbohydrate source in its energy products. When cola, fructose-containing gel, sugary sports drink, honey, or other simple carbohydrate sources are added, a carbohydrate mixture of a different composition enters the stomach and intestines.
Maltodextrin breaks down into glucose units during digestion, which are absorbed primarily through the SGLT1 transporter. Free glucose uses the same absorption pathway. If an athlete consumes a larger amount of glucose or a glucose-based product alongside maltodextrin, the two sources burden the capacity of the same transport system.
Fructose is absorbed through another transporter called GLUT5. However, it does not follow from this that the body utilizes fructose more easily or quickly as a direct energy source. A significant portion of absorbed fructose is first processed by the liver, and then it can become more widely available energy through various metabolic pathways.
The body does not selectively process simple sugar while setting aside maltodextrin. The various carbohydrate sources are processed simultaneously. However, by adding simple sugars, maltodextrin will contribute a smaller portion of the total energy intake, while the concentration, composition, and absorption pathway of the carbohydrate mixture formed in the stomach will change.
This can cause the Hammer fueling system, originally designed for maltodextrin, to lose its predictability. The athlete no longer follows the system on which the dosing recommendations for HEED, Hammer Gel, or Perpetuem were based.
Fructose absorption capacity can also vary significantly from person to person. If the consumed amount exceeds the athlete's current tolerance, some of it may pass further into the intestines. In such cases, the flow of fluid into the intestines and fermentation may increase, contributing to bloating, abdominal distension, nausea, or diarrhea. The risk can be further increased by heat, dehydration, high intensity, and excessively high hourly energy intake.
What happens when simple sugar is added to the system?
When consuming another gel, sugary sports drink, or cola, the added carbohydrate enters the same stomach contents where the Hammer product is located. This does not render maltodextrin unusable, nor does it "turn off" the product. The change occurs in the quantity, composition, and concentration of the entire mixture.
This difference is professionally important. The problem arising from mixing is usually not some chemical incompatibility. It is much more about disrupting the originally planned fueling protocol.
Hourly carbohydrate and calorie intake increases
Suppose an athlete has calculated the energy from HEED and Hammer Gel in advance. At the refreshment station, they drink two deciliters of cola, then a few kilometers later, consume another type of gel. A significant additional amount of carbohydrates enters their body in a short time, which was not part of the original plan.
Often, the athlete only perceives that they drank a little cola or consumed another gel. For the digestive system, however, all ingested calories and carbohydrates add up. At higher intensity, in hot weather, or with dehydration, stomach emptying can slow down anyway, so the extra energy can easily exceed the amount that can be processed at that moment.
The problem can be further exacerbated if the athlete continues with the originally planned Hammer doses unchanged. In such cases, the cola or foreign gel does not replace an earlier energy source but rather increases the hourly intake in addition to it.
The concentration of stomach contents changes
Proper dilution of a drink alone does not guarantee that the same concentration will remain in the stomach. If the athlete consumes a thick gel, cola, sugary bar, or gummy bears alongside it, the entire stomach contents can become more concentrated. This would require an adequate amount of water, which many people do not drink during competition.
Due to the longer carbohydrate chains of maltodextrin, the same amount of energy can be delivered with fewer dissolved particles than with simple sugars. When glucose, fructose, sucrose, or other short-chain sugars are added, the number of particles in the solution can increase, along with the osmotic load.
High carbohydrate intake and concentrated solutions can be linked to gastrointestinal discomfort during sports. The total load is always more important than the individual dilution of each product.
The absorption pathway changes
Different carbohydrates pass through the intestinal wall in partly different ways. Glucose released from maltodextrin and directly consumed glucose use the same SGLT1 transporter. Fructose is absorbed through the GLUT5 transporter.
This difference allows certain sports nutrition systems to use multiple carbohydrate sources simultaneously. However, such approaches are generally based on higher carbohydrate intake, precise glucose-fructose ratios, and targeted gut training.
If someone occasionally adds such a product to their Hammer fueling, it does not automatically create a consciously designed multi-transporter system. It simply changes the ratio of carbohydrate sources and the total hourly load.
Energy supply becomes unpredictable
One of the advantages of the Hammer system is its predictability. The athlete can know exactly when and how much energy they have consumed. After unexpectedly adding cola, banana, sugary drink, or another gel, this control ceases.
A temporary energy boost can easily encourage further consumption. If a feeling of fullness or nausea develops later, the athlete often cuts back on drinking and fueling. Thus, a short period of excessive intake can be followed by a longer period of energy and fluid deficiency. Fluctuating fueling often causes more problems than a more moderate, consistently maintained protocol.
Cola also counts towards fueling
Cola is a common example because it is readily available in the second half of races, is sweet, may contain caffeine, and can provide a quick pick-me-up. A few sips may seem harmless, but it can represent a significant amount of sugar, especially if repeated at several refreshment stations.
The sugar it contains adds to the carbohydrates from gels and drinks. Caffeine also enters the system, so its amount must also be considered. If the athlete's stomach is already emptying more slowly, the carbonation, sweetness, and extra energy together can cause an unpleasant feeling of fullness.
It is conceivable to have an individual fueling strategy in which cola plays a pre-planned role. However, this is a different protocol. For consistent testing of the Hammer system, it is advisable to omit it, especially during initial tests and long training sessions before the event.
Science also knows other carbohydrate strategies
Some sports nutrition research suggests a combination of glucose and fructose sources with a high hourly carbohydrate intake, typically approaching 60–90 grams. This is based on the fact that glucose and fructose are absorbed through different intestinal transporters, thus increasing the oxidation of externally sourced carbohydrates in the case of a well-trained digestive system.
However, this is a different sports nutrition approach, with its own dosing, fluid requirements, and often targeted gut training. Its existence does not mean that it is advisable to casually add fructose-containing products to a maltodextrin-based Hammer protocol. If someone chooses the method of high carbohydrate intake based on multiple carbohydrate sources, they must build and practice its entire system during training.
Randomly mixing two different concepts does not reliably provide the benefits of either method. In such cases, the athlete easily consumes more energy than recommended by Hammer, while also not following the precise carbohydrate ratios and dosing of the other system.
When can it truly be said whether a Hammer product works?
A product can only be fairly evaluated if its use follows its associated recommendation. If someone drinks HEED and also consumes various gels, sugary isotonic drinks, cola, and refreshment station foods, the result no longer solely reflects the performance of HEED or Hammer Gel.
During the initial trials, it is advisable to use a simple, transparent plan. The amount of fluid, energy, and electrolytes should be predetermined, and then it is worth observing the conditions, intensity, and stomach reaction during training. The effect of a single change is thus much easier to recognize.
A significant portion of fueling errors are quantitative problems. Too many calories arrive in a short time, too little water accompanies the gel, the athlete follows a plan designed for cool weather even in the heat, or loses the rhythm of dosing due to fatigue. Mixed product use adds to these fundamentals, further complicating the understanding of what caused the complaint.
How to use the Hammer fueling system consistently?
For efforts under three hours, HEED and Hammer Gel can form a well-planned energy source. For longer training sessions and races, Perpetuem can be the focus of fueling, depending on individual needs and effort. Electrolyte replacement can be regulated separately with Endurolytes products, allowing it to be adjusted to temperature, intensity, and the extent of sweating.
The exact amount should always be determined based on the athlete's body weight, effort intensity, fitness, individual digestive tolerance, and the weather. Only use a protocol in competition that has already been tested in longer training sessions under similar conditions to the event.
If, in an unexpected situation, another energy source must be used, include its total carbohydrate and calorie content in the intake for that hour. In such cases, the original dosing must also be adjusted. The body processes all consumed products together, regardless of which bottle, pouch, or refreshment table they came from.
That's why we say that the Hammer Nutrition fueling system should be used cleanly and consistently. This maintains the predictability on which the products' dosing is based, and this is how it can truly be determined how it works for a given athlete.
