Background
CONTRACTION
CrossFit includes Olympic weightlifting, powerlifting, and gymnastics in various combinations of overloads and repetitions with limited rest periods or no rest between training sets. Therefore, CrossFit combines intense and resistance training [High-intensity exercise leads to an accumulation of lactate and hydrogen ions (HOne of the most popular supplements among athletes is caffeine (CAF; 1,3,7-trimethylxanthine). Through its mechanism of action, which includes effects on the central nervous system (CNS), an increase in the amount of free fatty acids that are readily available, and a direct effect on muscle contraction, CAF supplementation at doses of 3–6 mg/kg body weight (BW) improves long-term aerobic exercise performance [There are few studies about the effect of nutritional strategies on the acute response to high-intensity exercise [Consumption of NaHCO