... Rapid weight loss (RWL) is frequently practised in sports that have weight class restrictions (Khodaee, Olewinski, Shadgan, & Kiningham, 2015;Reale, Slater, & Burke, 2017a), including combat sports such as mixed martial arts (MMA) (Barley, Chapman, & Abbiss, 2019;Matthews, Stanhope, Godwin, Holmes, & Artioli, 2019). The weight-making practices of MMA athletes have recently been a subject of much interest (Andreato et al., 2014;Barley, Chapman, & Abbiss, 2018;Connor & Egan, 2019;Coswig, Fukuda, & Del Vecchio, 2015;Coswig et al., 2019;Crighton, Close, & Morton, 2016;Hillier et al., 2019;Jetton et al., 2013;Kasper et al., 2019;Matthews & Nicholas, 2017). Notably, the prevalence and magnitude of the RWL process is greater in MMA than other combat and weight category sports (Barley et al., 2019;Matthews et al., 2019), with the %body mass loss usually~5% to 10% in the week prior to competition (Barley et al., 2018;Coswig et al., 2015Coswig et al., , 2019Crighton et al., 2016;Hillier et al., 2019;Matthews & Nicholas, 2017). ...