With several people engaging in fitness and sports, the belief that supplements are the magical key to improvements in performance is making the rounds. Vitamin and mineral supplements are widely used by the general population, which we will address later. This article will cover supplements commonly used by fitness enthusiasts and athletes. Are you using supplements backed by evidence for its efficacy or are you just burning a hole in your wallet? You’ll find out now!

To begin with, what are supplements? Supplements are defined as “a concentrated source of nutrients or other substances with a nutritional or physiological effect.” (1). Like the name suggests, they are to be used to correct nutritional deficiencies or support specific physiological functions. To put it in simple terms, in the absence of food providing adequate nutrients, supplements can be used. That is, to supplement a diet. Supplements are commonly sold as pills, powders, tablets or capsules with a specific dose. The nomenclature of ‘supplements’ varies globally. While in Europe, they are termed as food supplements, in USA they are known as dietary supplements. The Food Safety and Security Act in India have also listed ingredients that a product should contain in order to be classified as a supplement. (2)

(1) Whey Protein: Whey is a milk protein and the water soluble part of milk. Whey protein by itself is marketed in three main forms. (3)

  • Whey isolate: Contains higher percentage of protein (~85-90% or more) since lactose and fat are removed.
  • Whey concentrate: Lower percentage of protein (~80% or more) compared to isolate since lactose and fat are not removed.
  • Whey hydrolysate: Partially pre digested to aid rapid absorption.

Why whey protein? Do we really know why it is this popular? Or are we just consuming it because everyone else is? Whey protein is rich in essential amino acids compared to its counterparts such as eggs, soy and meat. In specific, it is rich in branched chain amino acids (BCAA) which play an important role in muscle protein synthesis. In fact, whey protein has a biological value (BV) that is greater than the BV of an egg by 15%! (3). BV denotes how fast and how well our body can use the protein consumed. Apart from this, one scoop of whey protein gives anywhere between 20-25g of protein (or more based on the brand)! Convenient isn’t it? its property of rapid digestion, concentration of amino acids and convenience is what makes it popular.

How does whey fare when compared to other protein sources? A study by Tang et al. in 2009 (4) compared the effects of whey hydrolysate, casein (another milk protein) and soy protein isolate on mixed muscle protein synthesis (MPS). It was found that whey protein stimulated mixed MPS to a greater extent compared to soy and casein, both at rest and after exercise. However, soy stimulated mixed MPS greater than casein in both scenarios.

Do you have to consume whey? That depends! Like I mentioned before, whey protein provides 20-25g of high BV protein per scoop and if you are unable to meet your daily protein requirements through your diet, then go ahead. Vegetarians who find it difficult to incorporate complete protein sources into their diet or those involved in strength and endurance training who require higher levels of protein will find supplementing beneficial. You can still consume whey otherwise, simply because it is convenient and light on the stomach. In fact, whey can be added to oatmeal and smoothies to increase the protein content. At the end of the day, it is a matter of personal preference. Remember, it is a supplement.

(2) Casein : Casein is also a milk protein like whey and is a complete protein. The difference between whey and casein lies in their digestion. Contrary to whey which is rapidly digested, casein is a slow digesting milk protein. Casein, like any other protein can be used to meet daily protein requirements but whey seems to be the ideal post workout protein of choice.
However, casein releases amino acids at a much slower rate, so ideally it can be taken before bed, to aid in recovery.

(3) Branched Chain Amino Acids : Branched Chain Amino Acids or commonly known as BCAAs are a group of three amino acids Leucine, Isoleucine and Valine. They are also Essential Amino Acids which means they need to be obtained from the diet. Supplementing BCAAs are popular as it is thought to stimulate muscle protein synthesis (6). Contrary to this, a recent review concluded that BCAA supplementation alone cannot promote muscle protein synthesis (6).

Does BCAA consumption help in preventing fatigue? Serotonin regulates feelings of arousal, sleep and mood and is thought to be linked to central fatigue after vigorous exercise (7). The amino acid Tryptophan is a precursor to serotonin production. Post a bout of exercise, there is a decrease in BCAAs in the plasma and an increase in free tryptophan, thus increasing the free tryptophan/BCAA ratio. It is thought that supplementing with BCAA could balance this increase and delay fatigue (7). However, most studies provided a combination of BCAAs and carbohydrates during exercise (8). Although BCAAs are thought to reduce markers of muscle damage and soreness after strenuous exercise, its efficacy in doing so post high intensity exercise is questionable (9). Further, there is no direct positive link between BCAA supplementation and reducing markers of muscle damage.

Do you need BCAAs? Honestly, no. If you are able to maximise your daily protein intake and meet them via complete proteins, supplementation with BCAA is not necessary. Complete proteins such as eggs, meat, dairy, whey protein, tofu and other soy products already have BCAAs. Maximise your protein through food/other supplements everyday and save some $$$ on the BCAA!

(4) Glutamine : L-glutamine is an amino acid that is found in protein rich foods like meat, eggs, dairy and tofu. Our body can make glutamine, but there are times when our requirements exceed how much our body produces. So, it is a conditionally essential amino acid. It is to be noted that it does become an essential amino acid only during critical illness or injuries (10).
If you are taking glutamine to build muscle or improve body composition, then hold on to your money. Studies have consistently shown that consuming glutamine does not affect body composition (11). In fact, glutamine does not augment rates of muscle protein synthesis in healthy individuals either! Studies have used doses up to 900 mg/kg lean mass and noticed no increase in lean mass or muscle protein synthesis (12). If you are perfectly healthy, with no serious injury or illness, then glutamine isn’t for you.

What about recovery? Glutamine is widely recommended for aiding recovery post training. A recent study did find that co-ingestion of glutamine and leucine (another amino acid) did in fact lead to faster recovery compared to a placebo. Muscle soreness did not differ between the two. (13). Besides strength recovery, it could help in reducing muscle soreness after strength exercise (14,15). Supplementation of glutamine around exercise does seem to enhance strength recovery and possibly reduce muscle soreness.

Like mentioned before, glutamine becomes an essential amino acid in the critically injured or sick individuals. Although exercise also acts as a stressor, immunosuppression observed after exhaustive exercise is not due to plasma glutamine (16). But, what glutamine could benefit is the intestine. Glutamine is thought to be more relevant than glucose as an energy substrate for the gut (17). Hence it could help in reducing exercise induced dysfunctions of the gut.

Thorough research is needed before starting supplement usage. First, it is imperative to understand if there is evidence for the efficacy of the supplement. Second, think about what the use of the supplement is and if it is applicable to your sport/physical activity. Finally, make sure you purchase your supplements directly from the manufacturer’s website. Make sure that the brand you buy is authentic and widely used. Supplements from third party websites could be adulterated/contaminated. The ‘informed sport’ icon on the product is one way to ensure that it is safe. With this in mind, always tell yourself that these are just supplements to a well balanced diet.


(1) EFSA. Food supplements.
(2) Health Supplements and Nutraceuticals Emerging High Growth Sector in India
(3) Smithers, GW. Whey and whey protein- from ‘gutter to gold’. International Dairy Journal. 2004; 18(7): 695-704
(4)Tang, JE, Moore, DR, Kujbida, GW, Tarnopolsky, MA, Phillips, SM. Ingestion of whey hydrolysate, casein, or soy protein isolate: effects on mixed muscle protein synthesis at rest and following resistance exercise in young men. Journal of Applied Physiology. 2009;107(3): 987-992.
(5) Examine. Casein protein.
(6) Wolfe, RR. Branched-chain amino acids and muscle protein synthesis in humans: myth or reality? Journal of the International Society of Sports Nutrition. 2017; 14(1): 1-7.
(7) Blomstrand, E. Amino acids and central fatigue. Amino Acids. 2001;20 (1):25-34.
(8) Blomstrand, E. Role for Branched-Chain Amino Acids in reducing central fatigue. The Journal of Nutrition.2006;136(2):544S-547S.
(9)Fouré A, Bendahan D.Is Branched-Chain Amino Acids Supplementation an Efficient Nutritional Strategy to Alleviate Skeletal Muscle Damage? A Systematic Review. Nutrients.2017;9(10):
(10) Lacey,JM, Dr. PH, Wilmore, DW. Is glutamine a conditionally essential amino acid?Nutrition Reviews. 1990;48(8):297-309.
(11) Ramezani Ahmadi, A, Rayyani, E, Bahreini, M, Mansoori, A. The effect of glutamine supplementation on athletic performance, body composition, and immune function: A systematic review and a meta-analysis of clinical trials. Clinical Nutrition. 2018;1-16
(12) Candow, DG, Chilibeck, PD, Burke, DG, Davison,KS, Smith-Palmer,T. Effect of glutamine supplementation combined with resistance training in young adults. European Journal of Applied Physiology. 2001; 86(2):142-9.
(13)Waldron,M, Ralph C, Jeffries O, Tallent J, Theis N, Patterson SD. The effects of acute leucine or leucine-glutamine co-ingestion on recovery from eccentrically biased exercise. Amino Acids.2018;50(7):831-839.
(14) Street,B, Byrne,C, Eston, R. Glutamine Supplementation in Recovery From Eccentric Exercise Attenuates Strength Loss and Muscle Soreness. Journal of Exercise Science and Fitness. 2011;9(2):116-122.
(15) Legault, Z, Bagnall, N, Kimmerly, DS. The Influence of Oral L-Glutamine Supplementation on Muscle Strength Recovery and Soreness Following Unilateral Knee Extension Eccentric Exercise. International Journal of Sports Nutrition and Exercise Metabolism. 2015;25(5):417-426.
(16) Hiscock,N, Pedersen, BK. Exercise-induced immunodepression- plasma glutamine not the link. Journal of Applied Physiology.1985; 93(3): 813-822.
(17) Cruzat,V, Rogero, MM, Keane, KN, Curi, R Newsholme, P. Glutamine: Metabolism and Immune Function, Supplementation and Clinical Translation. Nutrients. 2018; 10(11):1-31.

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