J Pearce, L E Norton

In this summary, stacking is defined as the consumption of two or more supplements at the same time in an attempt to maximise results. This practice originated from anabolic steroid regimes of body builders and other resistance training athletes where products were combined, often to address the side effects or potentiate the actions of individual products.1 A more global view of supplement stacking in sports nutrition finds that supplement combinations can be deliberate or unintentional. Deliberate stacking aims to take advantage of positive physiological responses that arise from combining nutrients, foods or compounds (eg, vitamin C enhancing iron absorption). Few studies have examined the possible benefits to stacking2–5 and have produced equivocal results despite theoretical support. Combining creatine with β-alanine had a unique effect on delaying fatigue while stacking creatine with hydroxy-B-methylbutyrate produced additive effects on lean body mass.4 ,5 The combination of β-alanine (intracellular) and bicarbonate (extracellular) buffers for events involving sustained high-intensity exercise that produces significant acidosis warrants comprehensive study.6 While stacking some supplements may provide additional benefits, some athletes may not be aware that taking multiple supplement products creates the potential for doubling up on some ingredients or co-ingesting ingredients that are best not combined. Inadvertent or unintentional …