Acute nitrate supplementation does not improve crossfit's physical performance, a double-blind cross-over study

Crossfit is a rising sport that demands a combination of strength and muscular endurance and has been gaining space in the national territory. Inorganic nitrate has been widespread in the literature as an ergogenic resource for increasing sports performance. Due to the lack of scientific consensus, the present study aimed to evaluate the effect of sodium nitrate supplementation on the performance of 18 amateur athletes (10 men and eight women) of Crossfit in the Cyndi protocol. A double-blind, cross-over study with a seven-day washout was performed. Initially, an anthropometric and body composition assessment was carried out and then the physical tests, divided into two meetings, where each participant was randomly given an acute dose, two hours before the beginning of the exercise, containing 10 mg/kg of sodium chloride (placebo) or sodium nitrate. A 24-hour recall was performed before each test. The number of movements each participant was able to perform in 20 minutes was computed, as well as the subjective perception of effort at the end of the activity. There were no statistical differences in the number of movements performed between the nitrate and placebo groups for men (531 +/- 139 and 515 +/- 158) and women (599 +/- 144 and 534 +/- 109). In addition, Borg and food intake were similar between groups. Thus, apparently, there is no benefit in the sporting performance of amateur crossfit athletes in the face of acute inorganic nitrate supplementation, allowing the conduction of new studies with different protocols and physical tests.