“…Systematic reviews and analyses, which synthesize the outputs of many studies into a pooled estimate of outcome are at the top of the evidence hierarchy. Indeed, such information is available on products such as caffeine (Burke, 2008;Conger et al, 2011;Glaister & Gissaine, 2017), including its specific delivery in energy drinks (Souza et al, 2017), bicarbonate (Carr et al, 2011b), creatine (Branch, 2003;Mujika & Padilla, 1997), b-alanine (Hobson et al, 2012;Saunders et al, 2016), nitrate/beetroot juice (Hoon et al, 2013;McMahon et al, 2017), antioxidant supplements (Braakhuis & Hopkins, 2015), N-acetylcysteine (Rhodes & Braakhuis, 2017), and polyphenols (Somerville et al, 2017). Other meta-analyses target specific uses of sports products, such as, in the case of sports drinks and gels, carbohydrate intake during endurance sport (Stellingwerff & Cox, 2014).…”