Taekwondo is a combat sport that has been in the Olympic games since 1988 and is growing in popularity. Taekwondo involves short bursts of high-intensity activity (~ 1–5 s) interspersed with low-intensity movements (1:2–1:7 ratio) . A taekwondo match is comprised of three two-minute rounds interspersed with one-minute of passive recovery. Due to the length, intensity, and intermittent nature of a taekwondo match, athletes require well-developed non-oxidative (phosphocreatine and glycolytic) and oxidative energy systems [2,3,4]. Throughout a match, the relative contribution from the anaerobic glycolytic system increases due to the short recovery between rounds [3, 4]. In particular, hydrogen ions (H+) may accumulate during a match and potentially impair performance . Specifically, H+ impair exercise performance through inhibition of key glycolytic enzymes (i.e., phosphorylase and phosphofructokinase), impaired calcium handling, and reduced myosin ATPase activity .
Dietary strategies including supplements known to alter either extracellular or intracellular buffering capacity or alter the contribution from the glycolytic energy system may enhance taekwondo performance . Sodium bicarbonate (SB) supplementation improves extracellular buffering capacity and enhances high-intensity exercise , including combat sports performance [9,10,11,12]. Lopes-Silva (2018) demonstrated that acute SB supplementation (300 mg∙kg− 1) increased glycolytic metabolism and enhanced taekwondo performance .
Another potential dietary strategy is creatine (CR) supplementation. CR is an organic compound naturally produced in the body from reactions involving arginine, glycine, and methionine in the kidneys and liver . CR supplementation increases phosphocreatine stores within the muscle by ~ 20
In theory, co-ingestion of SB and CR may provide additional ergogenic effects since they act through different mechanisms. In a crossover design, Barber et al. (2013) supplemented trained males (n= 13) with CR (20 g) and SB (0.5 g/kg) for only 2 days (with a relatively short 3-week washout) compared to either CR or PLA alone. Mean and peak power was higher during repeated sprints following co-ingestion compared to CR or placebo (PLA) alone . Six days of CR Co-ingestion (20 g∙day− 1) and an acute dose of SB improved swimming performance by 1.5