A review in the International Journal of Sport Nutrition and Exercise Metabolism discussed evidence for the safety and efficacy of supplements for athletes.
A dietary supplement is an ingested compound that is purposefully consumed, along with a habitual diet, to support a specific health or performance benefit. There are four categories of dietary supplements: supplements to prevent or treat nutrient deficiencies, supplements to provide energy and nutrients during training, and supplements to, directly and indirectly, enhance performance.
Some supplements can be harmful to the athlete’s health and performance. An athlete’s reputation may also be affected if the supplement is contaminated with a banned substance. A recent review in the International of Sport Nutrition and Exercise Metabolism summarized the evidence on the use of specific supplements to help athletes make informed decisions on the use of dietary supplements.
Supplements for nutritional deficiencies can lead to gastrointestinal side effects if the athlete does not have a deficiency
Supplements to prevent and treat nutrient deficiencies are necessary to optimize physiological and cellular functions. A complete nutritional analysis is required to detect nutrient deficiencies; however, not all nutrient deficiencies are easily detected. The most common deficiencies that occur in athletes are losses in iron, calcium, and vitamin D. Supplementation of these nutrients is required only if clear deficiencies are identified. These supplements can lead to gastrointestinal side effects if the athlete has adequate stores.
Supplements that provide energy and nutrients in a practical form are often used during activity. Sports drinks, energy drinks, and sports gels and confectionery provide quickly absorbed carbohydrates for energy supplementation. Electrolyte replacement products replenish losses of salts and fluid to correct dehydration. Lastly, protein supplements are normally consumed after exercise for recovery.
Few studies have confirmed claims of products that claim to improve sports performance
There are many marketed products that claim to directly improve sports performance; nevertheless, few studies can confirm their practical and safe use. Caffeine is widely studied in endurance-based scenarios. Nitrates have contributed to improved time trials in performances lasting less than 40 minutes. Beta-alanine and sodium bicarbonate have mostly been studied in high-intensity training situations. Finally, creatine monohydrate provides gains in lean mass and muscular power and strength.
Protein for gaining weight has the most reliable evidence
Supplements providing an indirect benefit to performance can support the athletes’ general health and body composition. Vitamin D and probiotics have shown moderate benefit to support athletes immune system to prevent upper respiratory symptoms. Creatine monohydrate also supports improved recovery from delayed-onset muscle soreness. Lastly, supplements used to modify body composition include fat burners and weight gainers. The weight gainer with the most reliable evidence is protein and any evidence for the use of fat burners are inconclusive. Many of the body composition modifying products are banned substances.
Few dietary supplements are safe and effective for high-performance athletes
In conclusion, few dietary supplements are safe and effective for high-performance athletes. These dietary supplements should be experimented thoroughly in training as much as possible before athletes use them in actual competitions. A careful analysis is required to determine the actual need for supplementation and the potential risks to the athlete. This review offers a reliable source of information for athletes and their support team to make an informed decision about the use of dietary supplements.
Written by Jessica Caporuscio, PharmD
Reference: Maughan RJ, Burke LM, Dvorak J, et al. IOC consensus statement: dietary supplements and the high-performance athlete. Br J Sports Med. 2018.