Effects of Beetroot Juice Supplementation on Cognitive Function, Aerobic and Anaerobic Performances of Trained Male Taekwondo Athletes: A Pilot Study.

Hossein Miraftabi,Raúl Domínguez,Zahra Avazpoor,Mohammad Hossein Samanipour,Emerson Franchini,Mark E T Willems,Ramin Rafiei,Reid Reale,Sajjad Rezaei,Alireza Naderi,Amir Sarshin,Erfan Berjisian,Majid S Koozehchian

doi:10.3390/ijerph181910202

Abstract

Studies have shown that nitrate (NO3−)-rich beetroot juice (BJ) supplementation improves endurance and high-intensity intermittent exercise. The dose–response effects on taekwondo following BJ supplementation are yet to be determined. This study aimed to investigate two acute doses of 400 mg of NO3− (BJ-400) and 800 mg of NO3− (BJ-800) on taekwondo-specific performance and cognitive function tests compared with a placebo (PL) and control (CON) conditions. Eight trained male taekwondo athletes (age: 20 ± 4 years, height: 180 ± 2 cm, body mass: 64.8 ± 4.0 kg) completed four experimental trials using a randomized, double-blind placebo-controlled design: BJ-400, BJ-800, PL, and CON. Participants consumed two doses of BJ-400 and BJ-800 or nitrate-depleted PL at 2.5 h prior to performing the Multiple Frequency Speed of Kick Test (FSKT). Countermovement jump (CMJ) was performed before the (FSKT) and PSTT, whereas cognitive function was assessed (via the Stroop test) before and after supplementation and 10 min following PSTT. Blood lactate was collected before the CMJ tests immediately and 3 min after the FSKT and PSST; rating of perceived exertion (RPE) was recorded during and after both specific taekwondo tests. No significant differences (p > 0.05), with moderate and large effect sizes, between conditions were observed for PSTT and FSKT performances. In addition, blood lactate, RPE, heart rate, and CMJ height were not significantly different among conditions (p > 0.05). However, after the PSTT test, cognitive function was higher in BJ-400 compared to other treatments (p < 0.05). It was concluded that acute intake of 400 and 800 mg of NO3− rich BJ reported a moderate to large effect size in anaerobic and aerobic; however, no statistical differences were found in taekwondo-specific performance.

Highlights

Taekwondo is an Olympic combat sport, with matches contested over three 2 min rounds separated by 1 min rest
To determine if dietary NO3 − would improve specific anaerobic performance of taekwondo athletes, we analyzed the effect of 400 mg NO3 − (BJ-400) and 800 mg NO3 − (BJ-800) on FSKTmult
Contrary to the original hypothesis, the present study observed that neither beetroot juice (BJ)-400 nor BJ-800 increased the number of kicks in each set, the total number of kicks, or kick decrement index (KDI) compared with PLA

Summary

Introduction

Taekwondo is an Olympic combat sport, with matches contested over three 2 min rounds separated by 1 min rest It is a striking sport characterized by repeated highintensity bursts of punching and predominantly kicking techniques lasting ~1–5 s, interspersed by low-intensity bouncing actions lasting ~10–35 s in a range from 1:2–1:7 work-to-rest ratios within each of the rounds [1]. Campos et al [2] found that adenosine triphosphate (ATP) resynthesis during taekwondo competition is predominantly produced via the oxidative energy system (accounting for ~66 ± 6% of total energy cost). Both anaerobic glycolytic and ATP-PCr systems contribute to energy cost for ~4 ± 2% and. Nutritional supplement strategies that may improve performance or recovery as well as aiding oxidative and/or non-oxidative metabolism relevant in combat sport are of interest to taekwondo athletes [4]

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