For those of you with a routine of regular exercise, proper hydration and an adequate diet, have you ever wondered if dietary supplements could help you train harder, increase your physical performance, or even give you a competitive edge? The time has come to learn which supposed athletic performance enhancing supplements are safe and effective.
Common Dietary Supplements
Arginine is found in foods that contain protein, such as meat, poultry, fish, eggs, and dairy products. An adequate diet provides around 4-5 grams of arginine per day. It has been claimed that larger amounts of arginine will increase strength and aerobic activity. Supplements are considered to be safe when taken at doses of up to 9 grams per day, however, there is little scientific evidence to prove that arginine supplements improve athletic performance or increase strength.
Beetroot or Beet Juice
Beets and beet juice are one of the best natural food sources of nitrate. Why is nitrate important for athletes? Our bodies convert nitrate to nitric oxide, which expands the blood vessels, therefore increasing blood flow and the delivery of nutrients and oxygen to working muscles. Due to blood vessel expansion, it is thought that beets and beet juice may improve overall athletic performance. Research is conflicting on the effectiveness of beetroot supplementation. Some studies show that aerobic performance is improved, but not strength performance. Other research shows that supplementation is more effective in recreational exercisers and less effective in athletes. More research is necessary for a definitive answer regarding supplementation with beetroot. According to the Office of Dietary Supplements, “drinking moderate amounts of beet juice is safe, but it can turn your urine pink or red.”
Beta-alanine is an amino acid found in foods like meat, poultry and fish. Depending on your current diet, most people consume up to 1 gram of beta-alanine per day. It is used to increase carnosine levels in our muscles. Carnosine helps reduce the buildup of lactic acid. According to the Office of Dietary Supplements, “it’s not known whether it is safe to take beta-alanine supplements daily for more than several months.” Caution should be taken when considering a supplement as consuming 800 mg or more at one time is known to cause moderate to severe parasthesia, a burning sensation of the face, neck, chest, or back.
Branched-Chain Amino Acids (BCAAs)
Branched-Chain Amino Acids (BCAAs) are the amino acids leucine, isoleucine, and valine. They are found naturally in foods such as meat, fish, and milk and are used to provide energy during exercise. A good diet with adequate protein will generally provide 10-20 grams of BCAAs per day, a sufficient amount. According to the Office of Dietary Supplements, it appears to be safe to consume up to another 20 grams per day of BCAAs. There is little scientific evidence, however, to support the claims that BCAAs improve performance, build muscle, or speed up recovery.
Citrulline is an amino acid that our body produces naturally and is found in foods like watermelon, garlic, and onions. Our bodies take citrulline and convert it into nitric oxide, which can expand blood vessels. When blood vessels expand, blow flow and the delivery of oxygen to working muscles is increased. This leads to an increase in the ability of our body to remove waste products that lead to muscle fatigue. Research on citrulline is extremely limited, so there is little evidence to support an improvement in exercise ability or athletic performance with citrulline supplementation.
Creatine is a compound stored in the muscles and provides them with the energy they need to perform difficult exercises. Our bodies can produce about 1 gram of creatine per day and we consume creatine from sources like beef and salmon. Creatine supplements have been found to increase strength, power, and muscle contraction, however the extent of performance enhancement differs among individuals. Results are seen in activities that involve short bursts of effort followed by periods of recovery such as sprinting and weight lifting. According to the Office of Dietary Supplements, “creatine is safe for healthy adults to take for several weeks or months” Weight gain is a common side effect of creatine supplementation as it increases water retention. Muscle stiffness, cramps, and GI discomfort is also common.
Ginseng is the root of a plant that has been used in traditional Chinese medicine for thousands of years. There are many different kinds of ginseng, some of which are thought to improve stamina, fight fatigue, and increase overall performance. While ginseng supplementation may appear to be safe, it can cause headaches, sleep disturbances, and GI upset. There is little scientific evidence to support the claims of improved athletic performance.
Glutamine is an amino acid found in foods containing protein, such as meat, poultry, eggs, and dairy products. Our bodies make small amounts of glutamine from BCAAs, while we also consume an average of 3-6 grams of glutamine per day. According to the Journal of Nutrition, glutamine supplementation of up to 28 grams per day for 14 days was without ill effect. While there may not be any short-term negative effects, there is little scientific evidence to support any positive performance enhancement from glutamine supplementation.
Iron is an important mineral that delivers oxygen to the muscles and tissues throughout your body. When you are deficient in iron, your exercise performance is diminished. Recommended amounts are 8 milligrams for men up to age 50, 18 milligrams for women up to age 50, and 8 milligrams for people of both genders over age 50. Athletes, vegetarians, and vegans may need even higher iron intakes. Iron supplementation of less than 45 milligrams is considered safe for teens and adults. Higher doses may cause constipation, nausea, GI upset, vomiting, or fainting. Please contact a physician if you feel you are deficient in iron. If you are looking to improve your physical performance, eating a diet rich in foods like lean meats, seafood, beans, and nuts will provide sufficient amounts of iron.
Protein helps build, maintain, and repair the body’s muscles. This means that an adequate protein intake can improve athletic training and shorten recovery time. Amino acids are the building blocks of protein. Our bodies make some amino acids called non-essential amino acids. There are some the body can’t make, called essential amino acids, that we must get from food sources. Possible sources could include meat, fish, poultry, dairy products, grains, and legumes. An adequate protein intake provides all of the essential amino acids that aid in athletic performance and recovery. A general recommendation is to consume 0.8 grams of protein per kilogram body weight. Higher intakes of protein appear to be safe, however there is no proven benefit to consuming greater than necessary amounts. As an athlete, you can achieve your recommended protein intake through high-quality protein food choices.
If you’re looking to up your athletic performance or increase the effectivness of your workouts, schedule a nutrition consultation today!
Written by Sarah Brunner, RDN, CD; Elite Sports Clubs Registered Dietitian
Sarah is certified in food allergies/intolerances and nutritional counseling, Academy of Nutrition and Dietetics; has a certificate in Dietetics from Mount Mary University; and a BA in Education and Mathematics from the University of Wisconsin – La Crosse.