Dietary supplements are widely used in sports and are taken by both amateur and professional athletes. Supplements are used to promote health by providing essential nutrients or to compensate for potential deficiencies. They are also used to supplement macronutrients in order to meet nutritional needs even when daily food intake might not be sufficient. These include, for example, protein shakes, gels, bars, and sports drinks. Others use supplements to directly enhance performance, prevent muscle soreness, speed up recovery, or influence mood.
Many micronutrients and macronutrients play a role in processes critical to performance and recovery. It is essential that an athlete be able to train efficiently while avoiding injuries and illnesses. Of course, a healthy and balanced diet is very important and, when implemented correctly, will provide the body with the necessary micronutrients and macronutrients. Even elite athletes are not immune to an unbalanced diet and, due to increased loss/demand resulting from higher energy expenditure and intense physical stress, are actually at a greater risk of deficiency than the general population.³
Supplements can be broadly divided into these four categories¹:
- Supplements for the prevention and treatment of nutrient deficiencies
- Supplements that provide energy and nutrients in a convenient form
- Supplements that directly influence athletic performance
- Supplements that have an indirect effect on athletic performance
In the following section, I’d like to discuss these four categories in more detail. However, I’ll only mention those supplements that are either very common in elite sports and/or have good to very good evidence of their effectiveness. Excluded are those supplements that are intended to complement a vegetarian or vegan diet.
Category 1: Supplements for the Prevention and Treatment of Nutrient Deficiencies
Vitamin D plays an important role in most cells in the body. A deficiency would therefore negatively affect many systems in the body—primarily the immune system and bone density. The risk of a deficiency depends on the time of year (the body produces it when exposed to sunlight) and whether the sport is practiced primarily indoors or outdoors.
In the context of bone density, calcium must also be mentioned here. An additional calcium intake may be necessary, particularly for those who avoid dairy products and experience high physical stress combined with periodic energy deficits.
Iron: Endurance athletes in general and women with heavy menstrual bleeding should have their iron stores checked regularly and take supplements if necessary. During high-altitude training, higher iron turnover is to be expected, and in the vast majority of cases, it is recommended to support this phase with an iron supplement.
Magnesium is very often used in sports to prevent muscle cramps. However, there is no evidence to support its effectiveness in this regard. The causes of muscle cramps vary and are very rarely due to a magnesium deficiency.² In addition, magnesium can lead to gastrointestinal problems during physical exertion.
Category 2: Supplements that provide energy and nutrients in a convenient form
There are relatively clear guidelines regarding the amount of energy or nutrients needed for sports nutrition before, during, and after exercise. In certain situations, however, it is practically impossible to consume these amounts through normal, everyday food sources. With tight training schedules, it is simply a matter of time to eat a meal that provides the required amounts.
During exercise, any increase in energy intake must be easily digestible. This is where “sports nutrition” comes into play. In long-distance triathlons, athletes consume up to 120 g of carbohydrates per hour during exercise. To make this possible, athletes rely on sports drinks, gels, and energy bars. In addition to constantly replenishing energy, fluid balance must also be maintained to some extent. Electrolytes—particularly sodium—play an important role here. For recovery and to stimulate protein synthesis, a sufficient amount of amino acids is important. Various protein supplements help athletes reach the recommended amount of 20 g of protein per meal (with additional servings depending on the intensity of the workout).
Category 3: Supplements with a Direct Impact on Athletic Performance
One supplement with strong evidence of its performance-enhancing effect is caffeine. It increases endorphin release, which helps the body better cope with neuromuscular demands; the resulting increased alertness and reduced fatigue are beneficial in almost every sport. Creatine is widely used in many team and strength sports. Supplementation increases creatine stores in the muscles, thereby improving sprint capacity and the ability to perform multiple short, high-intensity bursts of activity.
Another popular supplement is nitrate, which is used for both prolonged submaximal exercise and high-intensity, intermittent, or short bursts of activity. Nitrate plays an important role in various muscle functions. Primarily, however, it increases the efficiency of oxygen utilization in muscle cells and boosts blood flow to the muscles. Beta-alanine, with its intracellular buffering capacity, has a similar effect during longer periods of high-intensity exercise. Sodium bicarbonate is also frequently used in longer, high-intensity sports. It acts as a buffer in the blood when the pH level rises—that is, when the muscles become overly acidic (due to lactate).
Category 4: Supplements with an Indirect Impact on Athletic Performance
Many of the supplements mentioned so far claim to make a direct contribution to athletic performance. All supplements that promote health, body composition, the ability to train hard, recover more quickly, adapt optimally, reduce susceptibility to injury, and facilitate a faster return to activity after injuries make an indirect contribution. For an athlete, consistent training is the key to success. Interruptions caused by illness or injury can often be prevented with sensible supplementation tailored to the specific stressor (travel, flu season, susceptibility to injury, etc.).
Thus, supplements that support the immune system, promote sleep, or provide essential nutrients for healing injuries and reducing inflammation may be appropriate in some cases. However, continuous supplementation is not recommended, as high-dose antioxidants can also have a negative impact on training-induced adaptation processes.
Important to note:
It is important for athletes to note that every supplement must be of the highest quality and therefore obtained from trustworthy and verified sources.⁴ Substandard supplements may contain contaminants and lead to a positive doping test!
Sämi’s Tip:
More isn’t always better! That’s why it’s essential to follow the recommended dosages and timing.
Buying Supplements. Tip:
Buy your supplements at pharmacies and drugstores. They’ll be happy to give you good advice.
Sources
- 1) Maughan RJ, Burke LM, Dvorak J, Larson-Meyer DE, Peeling P, Phillips SM, Rawson ES, Walsh NP, Garthe I, Geyer H, Meeusen R, van Loon LJC, Shirreffs SM, Spriet LL, Stuart M, Vernec A, Currell K, Ali VM, Budgett RG, Ljungqvist A, Mountjoy M, Pitsiladis YP, Soligard T, Erdener U, Engebretsen L. IOC consensus statement: dietary supplements and the high-performance athlete. Br J Sports Med. 2018 Apr;52(7):439–455. doi: 10.1136/bjsports-2018-099027. Epub 2018 Mar 14. PMID: 29540367; PMCID: PMC5867441.
- 2) Moretti A. What is the role of magnesium in skeletal muscle cramps? A Cochrane Review summary with commentary. J Musculoskelet Neuronal Interact. March 1, 2021;21(1):1-3. PMID: 33657750; PMCID: PMC8020016.
