Supplements in Sports Nutrition


Sports supplements represent a multi-million dollar industry. Active adults and athletes are often enticed by effective supplement marketing. The promises of enhanced performance among other claims are motivating factors to purchase alternative nutrition to achieve results. Lack of supplement regulation and quality control may mean unreliable and ineffective products are being used.

It’s estimated between 39 and 89 percent of the international supplement market are athletes with the highest frequency among older and elite athletes.

What Is a Supplement?

Supplements are considered an addition to an already healthy diet. Active adults or athletes may include supplements to help meet nutritional needs, improve nutrient deficiencies, enhance athletic performance or achieve personal fitness goals. Without a well-designed nutrition plan in place, supplementation is said to be rarely effective.

Supplement Regulation and Standards

Dietary supplements have been placed in a special food category and not considered drugs. Supplements aren’t required to be submitted to the Food and Drug Administration (FDA) for regulation. Although the FDA has the ability to review ingredients and health claims of supplements, very few are investigated. 

Sport supplement manufacturers are allowed to make health claims with FDA approval as long as the product statements are true and based on scientific evidence.

Unfortunately, very few supplements claiming ergogenic benefits are supported by clinical research. This leaves the active adult or athlete without a guarantee of safety, effectiveness, potency or purity of supplements for dietary or ergogenic purposes. 

  • Dietary supplements include vitamins, minerals, amino acids, herbs, botanicals, and extracts or concentrates from plants or foods. They are typically sold as capsules, tablets, liquids, powders or bars and required to be clearly labeled as a dietary supplement. 
  • Ergogenic aids include substances, drugs or techniques used to enhance athletic performance. They can range from acceptable practices of carbohydrate loading to “illegal and unsafe approaches such as anabolic-androgenic steroid use.” 

Evaluating the Benefit of Supplements

Supplement use remains controversial and is a personal choice. Common questions asked by active adults, athletes, and sports nutritionists relate to manufacturing and supplement quality. Locating evidence-based research information is highly advised before considering sports foods and supplements. The International Society of Sports Nutrition (ISSN) recommends evaluating the validity and scientific merit behind supplement claims for enhanced athletic performance. The following questions are suggested:

  •     Does the supplement claim make sense? 
  •     Is there scientific evidence available?
  •     Is the supplement legal or safe?

Supplements are marketed for health and exercise performance based on hypothetical applications gathered from preliminary research. The claims sound promising but often don’t agree with clinical findings. Reliable online references like the Journal of the International Society of Sports Nutrition or National Library of Medicine's Pub Med will help you discern if a supplement is based on sound scientific evidence or not.


If working with a sports dietitian or specialist, they can be a valuable resource in supplement research interpretation. The information gathered will enable you to make the best decision about taking sports supplements for health and athletic goals. 

How Science Classifies Supplements

Dietary supplements and ergogenic aids are marketed and claim to enhance the diet and athletic performance of an active adult or athlete. Clinical research continues to uncover flaws in these supplement health claims. The International Society of Sports Nutrition (ISSN) has provided a classification for supplements based on clinical research:

  1. Apparently effective: The majority of supplement research studies show safe and effective.
  2. Possibly effective: Initial supplement findings are good, but more research is required to examine the effects on training and athletic performance. 
  3. Too early to tell: Supplement theory makes sense but lacks sufficient research to support using it.
  4. Apparently ineffective: Supplements lack sound scientific evidence and/or research has shown the supplement to be clearly ineffective and/or unsafe. 

The International Society of Sports Nutrition (ISSN) indicates the foundation of a good training program is a sound energy balanced, nutrient-dense diet. If supplements are being considered, the ISSN suggests supplements only from category one (apparently effective).  Any other supplements would be considered experimental. They further discourage supplements in category three (too early to tell) and don’t support athletes taking supplements in category four (apparently ineffective). 

Supplement Value of Vitamins and Exercise Performance

Vitamins are organic compounds essential to regulating metabolic processes, energy production, neurological functioning and protection of our cells. Dietary analysis on active adults or athletes has reported vitamin deficiencies. Although research shows a possible benefit of taking vitamins for general health, there has been minimal to no ergogenic benefits reported. The following vitamins common to athletes have been researched as proposed nutritional ergogenic aids:

proposed nutritional ergogenic aids: Vitamins
NutrientErgogenic ClaimResearch Findings  
Vitamin Amay improve sports visionno improvement in athletic performance
Vitamin Dmay help prevent bone lossmay help with calcium co-supplement
Vitamin Emay prevent free radicalsdecrease in oxidative stress found/more research required 
Vitamin Kmay help bone metabolismelite female athletes show improved balance of bone formation and resorption
Thiamin (B1)may improve anaerobic thresholddoesn’t appear to enhance exercise capacity at normal intake
Riboflavin (B2)may enhance energy availability during exercisedoesn’t appear to enhance exercise capacity at normal intake
Niacin (B3)may enhance energy metabolism, improve cholesterol and blunt fat storesshown to decrease cholesterol but decrease exercise capacity
Pyridoxine (B6)may improve lean mass, strength, aerobic capacity and mental focuswell-nourished athletes show no improvement in athletic performance. Some improved fine motor skills when combined with Vitamins B1 and B12.
Cyano-cobalamin (B12)may increase muscle mass and decrease anxietyno ergogenic effect reported, however, when combined with vitamins B1 and B6 may reduce anxiety
Folic acid (folate)may increase red blood cells for better oxygen to muscle and decrease birth defectsfound to decrease birth defects in pregnant women, but shown not to enhance athletic performance
Pantothenic acidmay benefit aerobic energyresearch reports no enhanced aerobic performance
Beta-carotenemay help exercise-induced muscle damagemay help decrease exercise-induced muscle damage, but more research is required for improved athletic performance
Vitamin Cmay improve metabolism during exercisewell-nourished athletes indicate no enhanced performance

Supplement Value of Minerals for Athletes

Minerals are inorganic elements essential for metabolic processes, tissue structure and repair, hormone regulation and neurological function. Research indicates active adults or athletes have been deficient in these important elements. Mineral deficiency may negatively affect athletic performance and therefore supplementation may be helpful. The following mineral supplements common to athletes have been researched as proposed nutritional ergogenic aids:

proposed nutritional ergogenic aids: Minerals
NutrientErgogenic ClaimResearch Findings
Boronmay promote muscle growth during resistance trainingno evidence currently exists to support this theory
Calciummay promote bone growth and fat metabolismshown to stimulate bone growth taken with vitamin D and may promote fat metabolism. No ergogenic benefit for athletic performance. 
Chromiumsold as chromium picolinate and claims to increase lean mass and reduce body fatrecent studies show no improvement in lean mass or reduced body fat
Ironmay help improve aerobic performanceshown to only improve aerobic performance in athletes suffering from iron deficiency or anemia
Magnesiummay improve energy metabolism/ATP availabilityshown to only improve exercise performance in athletes suffering from magnesium deficiency
Phosphorus (phosphate salts)may improve energy systems in the bodyshown to enhance the aerobic energy system during endurance training. More research is required 
Potassiummay help with muscle crampingno ergogenic benefits reported and research remains unclear if it helps with muscle cramping
Seleniummay improve aerobic exercise performanceimprovements in aerobic exercise performance have not been demonstrated
Sodiummay help with muscle cramping and reduce risk of hyponatremiashown to maintain fluid balance during heavy training and prevent hyponatremia
Vanadyl sulfate (vanadium)may stimulate muscle growth, enhance strength and powernot shown to have any effect on muscle mass, strength or power
Zincmay reduce upper respiratory tract infections during heavy trainingshown to minimize exercise-induced changes to immune function during training

Water as an Ergogenic Aid for Athletes

Water is considered the most important nutritional ergogenic aid for active adults and athletes. If 2 percent or more of body weight is lost through sweat, athletic performance may be significantly impaired. Weight loss of 4 percent or more during exercise may lead to heat illness, heat exhaustion, or more severe adverse health effects. It is critical for active adults and athletes to implement hydration management during training and competitive events. The International Society of Sports Nutrition (ISSN) recommends: 

  • Consuming a sufficient amount of water and sports drinks to maintain fluid balance and hydration
  • Athletes should drink 0.5 to 2 liters per hour of fluid in order to offset weight loss
  • Don’t depend on thirst as an indicator to drink water or sports drinks
  • Athletes should weigh themselves prior to and following exercise
  • Consume three cups of water for every pound lost during athletic training
  • Avoid excessive weight loss techniques including sauna sweats, wearing rubber suits, using diuretics, vomiting, or severe dieting

The takeaway is to become well educated on proper hydration methods during athletic training. This will help you maintain proper fluid balance and provide a positive exercise experience. 

The Role of Dietary Supplements for Athletes

Dietary supplements can play an important role in an athletic diet. However, they should be viewed as supplements to the diet, not replacements for a good diet. While there are very few supplements backed by scientific evidence to enhance athletic performance, there are some shown to be helpful for exercise and recovery. Whether you’re an active adult, athlete working alone, or have hired a sports nutrition specialist, it’s important to stay current on supplement research. The following common nutritional supplements have been researched and classified as either: apparently effective, possibly effective, too early to tell, or apparently ineffective: 

Apparently effective and generally safe:

Muscle building supplements:

  • weight gain powders
  • creatine
  • protein
  • essential amino acids (EAA)

Weight loss supplements:

  • low-calorie foods, meal replacement powders (MRPs), ready-to-drink shakes (RTDs)
  • ephedra, caffeine, and salicin containing thermogenic supplements taken in recommended doses for appropriate populations (ephedra is banned by the FDA)

Performance-enhancing supplements:

  • water and sports drinks
  • carbohydrates
  • creatine
  • sodium phosphate
  • sodium bicarbonate
  • caffeine B-alanine

Possibly effective but more research required:

Muscle building supplements:

Weight loss supplements:

Performance-enhancing supplements:

  • post-exercise carbohydrate and protein
  • essential amino acids (EAA)
  • branched chain amino acids (BCAA)
  • HMB
  • glycerol

Too early to tell and lacks sufficient research:

Muscle building supplements:

Weight loss supplements:

  • gymnema sylvestre, chitosan
  • phosphatidl Choline
  • betaine
  • coleus forskolin
  • DHEA
  • psychotropic Nutrients/Herbs

Performance-enhancing supplements:

  • medium chain triglycerides

Apparently not effective and/or unsafe:

Muscle building supplements:

  • glutamine
  • smilax
  • isoflavones
  • sulfo-polysaccharides (myostatin inhibitors)
  • boron
  • chromium
  • conjugated linoleic acids
  • gamma oryzanol
  • prohormones
  • tribulus terrestris
  • vanadyl sulfate (vanadium)

Weight loss supplements:

  • calcium Pyruvate
  • chitosan
  • chromium (non-diabetics)
  • HCA
  • L-Carnitine
  • phosphates
  • herbal diuretics

Performance-enhancing supplements:

General Health Supplements Suggested for Athletes

Maintaining good health for active adults and athletes is essential. It is suggested athletes supplement with a few additional nutrients to stay healthy during intense exercise. The American Medical Association (AMA) recommends all Americans “ingest a daily low-dose multivitamin” to ensure proper amounts of nutrients in the diet. Although not recommended to enhance athletic performance, a multi-vitamin may be helpful for general health. Other research recommends the following additional nutrients for active adults and athletes:

  • glucosamine and chondroitin (preventative for joint pain and slowed cartilage degeneration)
  • vitamin C, glutamine, echinacea, and zinc (may enhance immune function)
  • omega-3 fatty acids (heart healthy fats endorsed by the American Heart Association (AHA))

A Word From VeryWell

Dietary supplements are generally not required for the well-nourished active adult or athlete. Many ergogenic aids are unreliable and should only be considered after careful evaluation of effectiveness, potency, and safety. However, sports supplements are here to stay and can play a meaningful role in your training program. Any supplement under consideration should be backed by chronic clinical studies and clear evidence of their health or ergogenic claims. In other words, become supplement smart for your health and athletic performance! 

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Article Sources
  • Kreider RB, Wilborn CD, Taylor L, et al. ISSN exercise and sport nutrition review: research & recommendations. Journal of the International Society of Sports Nutrition. 2010.
  • Thomas TD, Erdman KA, Burke LM. Nutrition and Athletic Performance. Position of Dietitians of Canada, the Academy of Nutrition and Dietetics and the American College of Sports Medicine. 2015.