Supplements: Boosting Athletic Performance?

We are surrounded with a large variety of supplements marketed towards improving our athletic performance. Packaging is labeled with all sorts of claims. For example…

“Proteins for humans only!”

“Supports Focus, Clarity, and Memory”

“Forces massive muscle growth directly on your chest and arms”

“Hardcore weight loss, extreme energy, maximum intensity”  or “WORKS to blast fat pockets”

Yes, these are actual claims off of some supplement bottles.

The problem is that there is little regulation on supplements. Effectiveness and safety do not have to be proven prior to selling.  If a product is found to be unsafe after use, the FDA can remove or limit sales at that point. Therefore, products can claim what they wish and leave out important information like serious side effects, potential organ damage, medication interactions, or that use could lead to a positive test of a banned substance. If you are an athlete subject to drug testing, it is your responsibility to know what is on the constantly updated banned substance list.  Consult with a Sports Dietitian before taking supplements.

Below is a list of popular sports supplements. Take note that all if these are also found in food sources, which should remain your top choice for nutrition.

Branched-chain Amino Acids − leucine, isoleucine and valine − are essential building blocks of protein. Found in protein foods, including meat, dairy, and legumes.

Uses: Prevent fatigue, improve exercise performance, improve concentration, reduce protein breakdown in muscles

Effectiveness: BCAAs are possibly effective for reducing muscle protein breakdown during exercise.  Some research suggests it may reduce muscle soreness. 

Safety: BCAAs supplements are rated as possibly safe when taken by mouth. Side effects may include fatigue and decreased coordination.

Click on image to see samples of Beet Root Supplements via Ruck Science. 

Click on image to see samples of Beet Root Supplements via Ruck Science. 

Beetroot Extract
Beetroot extract, a highly concentrated form of beetroot juice, is rich in nitrates that our body converts to nitric oxide(NO). Nitrates are also found in celery, lettuce, spinach, parsley, and other vegetables.

Uses: Increase NO production, increase blood flow to the muscles, improve exercise performance

Effectiveness: Beetroot extract taken before exercise may increase exercise performance, increase oxygen delivery to the muscles, and delay time to exhaustion. More evidence is needed to support effectiveness.

Safety:  Beverages, powders, and capsules of beetroot juice are generally safe when taken in appropriate amounts. Avoid NO supplements, which can cause stomach pain, electrolyte imbalance, and increased risk for bleeding.

Found in coffee, tea, soda, energy drinks, supplements, and other products.

Uses: stimulant, mental alertness

Effectiveness: Caffeine is effective for mental alertness and possibly effective for athletic performance by delaying feelings of exhaustion.

Safety: Caffeine is likely safe when used appropriately.  Side effects include jitteriness, gastric irritation, diarrhea, increased blood pressure, insomnia, inability to focus, and decreased absorption of calcium. It is unsafe when taken in very high doses, as in the case of supplements.

Found naturally in our muscles and brain. Common food sources include red meat and seafood.

Uses: Increase muscle mass, improve exercise performance

Effectiveness: Creatine is possibly effective for athletic performance.

Safety: Creatine supplements can cause nausea, diarrhea, stomach pain, muscle cramping, and dehydration. Drinking plenty of water is important. Avoid a combination of creatine, caffeine, and ephedra, which increases risks of serious side effects, including stroke.

Tart Cherry Juice
Made from the fruit of sour cherry. Contains ingredients thought to reduce inflammation. Also contains melatonin which helps to improve sleep patterns.

Uses: Decrease muscle pain, lessen exercise-related muscle damage, improve insomnia

Effectiveness: Tart cherry is possibly effective for improving sleep patterns, decreasing inflammation, and aiding in muscle recovery post-exercise.

Safety: Tart cherries or tart cherry juice or concentrate are safe when eaten.

Vitamin D
Obtained from sun exposure and found in some fish(salmon, halibut, sardines, tuna), mushrooms, and fortified dairy.

Uses: Maintain bone structure, support immune system function

Effectiveness: Adequate levels of vitamin D are required to maintain bone mass and support healing from injury.  Possibly effective for aiding in immune function.

Safety: If unable to meet needs with diet and sun exposure, then supplementation may be necessary.

Trusted Resources
Here are some helpful online resources for information about dietary supplements:

US Anti-Doping Agency 

World Anti-Doping Agency 

NCAA Sports Science Institute 

Natural Medicines Database 


Natural Center for Complementary and Integrative Medicine 

USDA Food and Nutrition Information Center 

When choosing supplements as an athlete, you need to assess 3 risks that will help you to determine if the supplement is a good choice.

1) Will it lead to a positive drug test? 2) Are there any health risks involved? 3) Is it a waste of my time and money? If the answer to any of these is yes, then think twice.

If you are considering taking a supplement for sport performance or for another reason meeting with a Registered Dietitian Nutritionist is recommended. An RD or RDN, especially one that is also Certified in Sports Dietetics, can advise you on the effectiveness of specific supplements, whether they can be obtained from food, and can help you to determine appropriate dosages.

Congrats on wrapping up another season. As you gear up for the Summer season or training for the Fall season, have fun, be safe and stay healthy!

Irene Gardner MS, RDN, CSSD

About Irene- Irene Gardner is the owner of IG Nutrition & Performance, Registered Dietitian Nutritionist,  A Certified Specialist in Sports Dietetics, with a Master's Degree in Nutrition. She is a former member of the Cal Women's Rugby Club, Berkeley All Blues, as well as the USA Rugby's Women's National 7s Team. She has also accumulated a number of rugby awards and honors along the way. Now, Irene is working full-time to help others live well and improve their performance through nutrition! She is currently collaborating with us at The Rugby Republic to bring nutritional information and tips to the ruggers. You can reach her at Twitter-@IG_Nutrition or on Instagram @IG_Nutrition.

Article References:
Academy of Nutrition & Dietetics: 
Natural Medicines Database
Dietary Supplement Label Database