People who regularly engage in strength training often use a combination of supplements that include whey protein, arginine and multivitamins. However, there is insufficient evidence to conclude that these supplements enhance athletic performance or increase muscle mass, according to WebMD.
Protein supplements are commonly used to repair damage to muscle following intense workouts, but these claims are not supported by sufficient evidence, states WebMD.
L-arginine is an amino acid that is advertised as enhancing the level of nitric oxide in the blood and thus enhancing blood flow during a workout. Most people already get enough arginine in their diet, and there aren't clear benefits to taking a supplement, according to WebMD.
Multivitamins may be helpful in the maintenance of good health for some individuals, but it is unclear if they offer any additional benefit relating to athletic performance, Mayo Clinic says.