Table 3.

Classification of supplements examined in this study

Categories of supplements	Sub-categories	Examples (from the supplements considered in this study)
Group A Evidence level: Strong scientific evidence for use in specific situations in sports using evidence-based protocols	Sports foods	Whey protein, gainer, egg powder, carbohydrate powder, soybean powder, protein-rich, and energy drink
	Medical supplements	Vitamin D, Vitamin B12, vitamin B complex, multivitamin, calcium, iron, calcium + vitamin D, vitamin B9, and zinc
	Performance supplements	Caffeine, creatine, beta-alanine, aspartic acid, and theophylline
Group B Evidence level: Emerging scientific support, deserving of further research	Food polyphenols
	Antioxidants	Vitamin C
	Tastants
	Other	Omega-3 fatty acids, carnitine, green tea, green coffee, fish oil, and flaxseed
Group C Evidence level: Scientific evidence not supportive of benefit amongst athletes or no research undertaken to guide an informed opinion	Category A and B products used outside approved protocols
	Named products	Vitamin E, glutamine, magnesium, amino acids, arginine, and branched-chain amino acids
	The rest
Group D Evidence level: Banned or at high risk of contamination with substances that could lead to a positive doping test	Stimulants	Ginseng, ephedrine, amphetamine, and methylphenidate
	Prohormones and hormone boosters	Testosterone, oxymetholone, nandrolone, metandienone, insulin, and erythropoietin
	GH releasers and peptides	Growth hormone
	Beta-2 agonists
	Selective androgen receptor modulators
	Metabolic modulators
	Other

Note. GH: Growth hormone