Comparação dos efeitos agudos da suplementação de nitrato e cafeína no desempenho de um protocolo de teste sprint em corredores recreacionais

Abstract

The use of ergogenic aids aimed at improving performance has been increasing among individuals practicing physical exercise. According to the International Olympic Committee, caffeine and nitrate are supplements with high scientific evidence and beneficial effects on sports performance. Caffeine aids in muscle contraction, enhancing strength, while nitrate increases plasma nitric oxide levels, improving vasodilation. Despite numerous studies on caffeine and nitrate, knowledge gaps remain regarding their effects on high-intensity exercise, particularly sprint-based efforts. This study compared the acute effects of caffeine and nitrate supplementation on a sprint interval training (SIT) protocol, focusing on perceptual variables (Rating of Perceived Exertion – RPE and Profile of Mood States – POMS), cardiovascular variables (Blood Pressure – BP and Heart Rate – HR), and performance variables (time and vertical jumps) in recreationally active runners. The study included 17 recreationally active male runners with an average age of 29.09 ± 10.64 years. Data collection occurred over four sessions, with a minimum interval of 72 hours between them. On the first day, participant characterization included anamnesis, a 24-hour dietary recall, anthropometric measurements (body weight, height, circumference, and skinfolds), and VO2max testing using the Weltman test. The intervention days involved protocols with and without supplementation (caffeine: ~6 mg/kg and nitrate: ~6.4 mmol NO3), applied randomly. Initially, a 24-hour dietary recall and the POMS questionnaire were completed. Vertical jumps were performed before and after the test protocol, consisting of ten all-out sprints. RPE was recorded between sprints, and BP and HR were measured at 1, 3, and 5 minutes post-test. Data were analyzed using two-way ANOVA for multiple comparisons to identify mean diferences and paired t-test was used to compare pre- and post-test jumps, with a significance level of p < 0.05. Caffeine proved more effective than nitrate and control conditions in reducing total sprint time (p < 0.001). Nitrate showed benefits during sprints 7 to 9 (p = 0.023; p = 0.012). Both supplements reduced RPE compared to the control. No significant differences were observed in BP, HR, POMS, or vertical jump variables. Caffeine supplementation outperformed nitrate in test protocol performance, while nitrate contributed to fatigue resistance during efforts. Both supplements effectively reduced RPE compared to the control but did not affect mood profile aspects. For sprint interval training, caffeine and nitrate supplementation may improve performance.