Expert Interview with Uwe Schröder: Nutritional Supplements for Athletes

Mr. Schröder, you hold a degree in oecotrophology and serve as a member and spokesperson on the board of the German Institute for Sports Nutrition. Could you briefly explain to us exactly what an oecotrophologist is?

U. Schröder: As an ecotrophologist, one has studied ecotrophology. In Germany, the term refers to the study of (home economics and) nutritional sciences. I completed my studies in Giessen and wrote my thesis at the Rijksuniversiteit Limburg in Maastricht (Netherlands). The term “oecotrophology” is derived from the Greek words “oikos” (house, household) and “trophein” (to nourish) and refers to the scientific study of nutrition and food in the context of the household and lifestyle. Today, the program is offered as a B.Sc. (Bachelor of Science) or M.Sc. (Master of Science) at numerous universities and colleges, and students can specialize from the outset—for example, focusing solely on the nutritional science component.

During my studies in oecotrophology, my focus was on nutrition, food chemistry, food technology, nutritional physiology, food hygiene, dietetics, and related topics. Graduates in oecotrophology therefore possess a broad range of knowledge and can be found in fields such as nutritional counseling, the food industry, public health, and research.

Among other things, you are also an expert when it comes to dietary supplements. In recent years, supplements have become increasingly popular. How do you explain this?

U. Schröder: In my view, numerous factors are responsible for the increased popularity of dietary supplements (DS) in recent years: changes in lifestyle and work habits, greater awareness of health issues, a trend toward individuality, and the health benefits of DS are examples.

The increasingly mentally and cognitively demanding work environment, which requires less energy but the same, if not increased—nutrient requirements, also contributes to this. Today, the goal is to consume many nutrients with fewer calories. This is difficult, especially since the food supply increasingly consists of highly processed foods with low nutrient density.

Added to this is a lack of time and the trend toward quick meals (fast food has exploded—and here, too, foods with low nutrient density are typically found). People are more concerned about their nutrient intake but often do not consume enough nutrients. Vitamins, minerals, trace elements, and phytochemicals are then supplemented to make up for this. Although professional associations have been advocating a “varied, needs-based, wholesome diet” for many years, the reality of dietary consumption looks quite different. Dietary supplements are seen as an easy way to either provide a comprehensive portfolio of as many nutrients as possible for basic coverage—or to specifically supply certain (individual) nutrients for specific indications.

General health awareness has also increased, and fitness and performance are highly valued—both at work and in leisure time. However, sustained high performance is not possible without an adequate supply of nutrients. Many are therefore looking for ways to optimize their diet and avoid nutrient deficiencies through dietary supplements. The problem here is often that there are no concrete laboratory analyses or dietary histories to serve as the basis for supplement decisions. Often, people consume too much of what is already present in sufficient quantities through their normal diet. But where there is a real deficiency, it is not being addressed. One example is the trace element iodine, which, in my view, leads a shadowy existence in supplementation but is of great importance, especially in sports: Iodine is lost through sweat, and overall intake has been declining significantly again in recent years.

Social media (especially influencers) and clever marketing strategies also contribute to the ever-increasing demand for dietary supplements. Another reason is the desire for increasingly personalized and individualized nutrition. Fitness trackers, smartwatches, and similar devices are now used to analyze one’s own athletic behavior and share it with others. This trend toward individualized (nutritional) concepts is also evident in dietary supplements. Some manufacturers now offer nutrient blends tailored to individual needs. Additionally, there is an effort to replace traditional medications with plant-based alternatives in the form of dietary supplements. Examples include NSAIDs (nonsteroidal anti-inflammatory drugs such as Diclo or Ibuprofen), which can be supplemented and, in some cases, replaced by plant extracts when taken over the long term.

Dietary supplements are particularly important for athletes when it comes to achieving peak performance. Can you briefly explain the role dietary supplements play in this context?

U. Schröder: Dietary supplements can support performance in various areas for athletes. However, the foundation is always a high-quality, individualized diet tailored to training and competition conditions, the training phase, and performance capacity—with as many natural foods as possible that are nutrient-dense and contain a comprehensive spectrum of phytochemicals.

Often, due to factors such as lack of time, food sensitivities, intolerances, availability issues, etc., the necessary intake of macronutrients and micronutrients cannot be achieved through food alone. This is where dietary supplements play a crucial role. A distinction must be made between substitution—that is, the replacement of a missing nutrient and supplementation, in which substances are ingested in addition to what is generally a sufficient supply; these substances are intended to support the performance of, for example, the immune system, recovery, and other parameters, usually in a situation- and time-specific manner.

Ergogenic (performance-enhancing) substances are specifically designed to improve efficiency in both training and competition. Dietary supplements are used for energy supply in the context of athletic activity—for example, carbohydrates in the form of bars, gels, and drinks; protein for recovery, muscle maintenance, and muscle building; and even certain fats to achieve very high energy levels during periods of extreme energy demand.

Trace elements, minerals, and vitamins in dietary supplements often replace losses through sweat and urine and compensate for nutrient deficiencies resulting from the regular consumption of energy concentrates lacking corresponding micronutrients. Ergogenic substances such as creatine or nitrate are specifically used to support better (smarter) training, higher training loads, faster recovery, and a performance-enhancing effect during competition. It is important that the selection of dietary supplements be tailored to both the athlete’s individual profile and the training situation, sport, exercise profile, and even the specific training session.

Other examples include dietary supplements such as protein shakes, amino acids, carbohydrates, and omega-3 fatty acids, which can help meet the increased demand for these macronutrients and micronutrients during exercise. Proteins, particularly whey protein, are often used to support muscle recovery and muscle protein synthesis following intense (strength) training. Sufficient protein, in turn, is crucial for the repair and growth of muscle tissue. Electrolyte supplements can help regulate electrolyte balance and effectively compensate for losses through sweat and renal excretion.

It is very important to note in this context that dietary supplements can never replace a balanced diet. The foundation for optimal athletic performance remains a well-planned and balanced diet. Therefore, individual needs should be assessed before taking any supplements, also to ensure that the supplements are effective and safe.

The German Institute for Sports Nutrition (DISE) also awards the DISE Seal of Recommendation. How important are such seals when it comes to trust and consumer protection?

U. Schröder: Seals and certificates on food products are intended to provide consumers with clear information about specific characteristics or quality standards of the food. Quality seals are viewed predominantly positively by consumers. They can help communicate information about the origin, production methods, and quality standards of food products. When consumers trust certain seals and view them as reliable indicators of specific characteristics, they can base their purchasing decisions on them.

For more than 70 percent, testing and quality seals on food products serve as a good guide, and more than half consider them useful for their purchasing decisions. The DiSE Recommendation Seal from the German Institute for Sports Nutrition (Deutsches Institut für Sporternährung e.V.), Bad Nauheim, strengthens the trust of athletes and consumers in the respective product.

The DiSE Recommendation Seal therefore contributes to the meaningful differentiation of a product. It communicates a potential added benefit that consumers can expect from using the product. A study conducted at the Medical Campus Peil or a scientific literature review with correspondingly positive results is a prerequisite for the awarding of the DiSE Seal of Recommendation.

To return to the topic of sports: Are there specific dietary supplements with which you have had particularly good experiences among athletes and which you would recommend?

U. Schröder: Over more than 30 years of supporting athletes, DiSE e.V. has gained experience with a wide variety of dietary supplements. Depending on the sport, training and competition conditions, the purpose of taking the supplement, and individual needs, a wide range of dietary supplements have been helpful in my view and still are. To supplement basic nutrition, vital complexes made from fruits and vegetables have proven effective, ensuring an adequate supply of phytochemicals. To support the immune system, especially in specific situations, organically bound zinc (zinc aspartate) in enteric-coated capsules has proven effective (zinc contributes to the normal function of the immune system).

An optimal supply of vitamin D throughout the year cannot be achieved without at least temporary intake of vitamin D supplements. Here, we use a combination of high-dose vitamin D3 and K2 in oil-based capsules.

In my view, creatine can effectively support performance in many sports, such as team sports, strength training, and fitness activities, and is therefore used regularly. To support the gut microbiota, we routinely rely on a highly concentrated, high-dose probiotic formulation containing a wide variety of different bacteria. In specific cases, I also consider the use of prebiotics as a source of soluble fiber to be beneficial, particularly during exercise.

Hydrogen carbonate plays a special role; in basic nutrition, it can be specifically used via hydrogen carbonate-rich mineral waters to stabilize the body’s own hydrogen carbonate buffer.

In performance-oriented sports, specific enzyme yeast cell preparations have also proven effective; these are used, for example, by the German Rowing Association.

In addition to your work, you are also a member of the board at DiSE. What does this position mean to you, and why did you decide to pursue this career path?

U. Schröder: In my work at DiSE e.V., I am able to work directly with athletes through nutrition coaching, as well as conduct and participate in continuing education and training programs for nutritionists, medical professionals, and coaches, and take on teaching assignments at various colleges and universities. Through my work on the board, I can help shape the direction of DiSE e.V. and play a key role in overseeing the awarding of the DiSE e.V. Seal of Recommendation.

I have a particular interest in translating scientifically and evidence-based data into practical dietary and hydration recommendations for large target groups—ideally with the help of sensible, safe, and effective dietary supplements.

Another service provided by the German Institute for Sports Nutrition is offering nutritional counseling for athletes. Can you briefly explain how a consultation works and which dietary supplements you recommend for which sports?

U. Schröder: Sports nutrition coaching is generally based on a medical history comprising a 7-day food diary, training plan, lab data, short-, medium-, and long-term training and performance goals, as well as an evaluation of individual food and taste preferences. During the initial consultation, we discuss the baseline data and set realistic goals together. Food choices are tailored to the individual’s specific circumstances and their training or competition schedule. As the process continues, we use follow-up consultations, which can also take place online or by phone—to fine-tune the selection of foods and dietary supplements to align with training, nutritional needs, lifestyle, and other factors. We rely on the cooperation and assistance of the athlete, as well as, if necessary, parents, caregivers, and coaches.

We use dietary supplements such as vegetable and fruit complexes to provide basic nutrition when a regular intake of at least five servings of vegetables and fruits per day from a variety of sources cannot be ensured. Probiotics and prebiotics are frequently used in endurance disciplines, but also in team sports and aesthetic sports. The administration of nutrients to support the immune system depends less on the sport and more on training conditions (e.g., training camps), the season, and the athletes’ overall micronutrient intake.

We generally use creatine in team sports, during targeted strength training phases across all sports—for example, in track and field, rowing, swimming, etc., but increasingly also in endurance sports. The use of vitamin D is based on individual laboratory diagnostic data in consultation with the medical team. In many cases, we use a broad-spectrum multivitamin and multimineral supplement to ensure a basic supply of vitamins and minerals.