Abstract
Rating of perceived exertion (RPE) is related to peripheral sensations and central discharge during exercise. Therefore, nutritional interventions that alleviate both peripheral and central demand during exercise may interfere on RPE response. Therefore, the aim of the present study was to test the effects of acute sodium nitrate supplementation on RPE and session RPE (RPE-s) during and after high-intensity intermittent exercise (HIIE), respectively. Fifteen subjects were submitted to an incremental exercise test to determine maximal aerobic speed (MAS), and afterwards randomly performed two HIIE (10 x 1 min at 100% of MAS and 1 min of passive recovery) 2h30min after the ingestion 8.4 mg·kg− 1 of both sodium nitrate (SN) and placebo. The RPE was measured during the warm-up (7 min at 75% of MAS), HIIE (after each effort), and 30 min after the HIIE (RPE-s). Area under the curve of RPE during HIIE was also calculated (RPEAUC) The comparison of RPE during the effort was performed by the Friedman test, while the comparison between RPE at 75% of MAS, RPEAUC, and RPE-s was performed by paired Student’s t test. SN reduced RPE (75% of MAS) (t = 4.52; p < 0.05), RPEAUC (t = 4.28; p < 0.05), and RPE-s (t = 3.92; p < 0.05) compared to placebo. During the HIIE, SN promoted lower RPE from the 5th to the 10th effort (z = 2.6–3.0; p < 0.05). SN supplementation reduces overall RPE during warm-up, HIIE and after exercise. This indicate the SN can be used as a strategy to reduce the effort perception during intermittent exercises. Other studies may want to investigate whether SN changes interferes on training load.