Effect of acute isotonic beetroot juice ingestion on cognitive function in recreational cyclists: a randomised crossover controlled trial

• Main Author: Lau, Ian Gern Liang
• Other Authors: -
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2023
• Subjects: Science::General
• Online Access: https://hdl.handle.net/10356/171859
• Institution: Nanyang Technological University

Beetroot juice (BRJ) and isotonic-carbohydrate (ISO-C) drinks are considered ergogenic aids to boost athletic performance. However, their combined impact on cognitive function remains unexplored. This study hence aimed to assess the acute effects of pre-exercise ISO-C and BRJ co-ingestion on cognitive function, compared to ingesting ISO-C alone. Eight males (26.8 ± 5.4 years; 68.4 ± 4.9 kg, 171.6 ± 2.9 cm) and four females (24.8 ± 4.3 years, 59.9 ± 7.7 kg, 164.4 ± 4.6 cm) who were recreational cyclists ingested ISO-C or ISO-C BRJ (ISO-CB) drink on two separate occasions which were minimally five days apart in a randomised, double-blind, crossover fashion. Following an hour post-ingestion, they completed a cycling protocol comprising two 10-min sets at 65% of their maximal power output, with five min of active recovery at 50 W after each set, before a 10 km time-trial. A Stroop test was then administered to assess cognitive function where mean reaction time and response accuracy were recorded. There were no significant differences in overall response accuracy (ISO-C=97.5 ± 4.1 % vs ISO-CB=97.0 ± 4.2 %; p=0.438) and reaction time (ISO-C=0.751 ± 0.155 s vs ISO-CB=0.746 ± 0.169 s; p=0.876) between the two drinks. There was also no interaction effect of drinks and stimulus conditions of the Stroop test on response accuracy (p=0.866) and reaction time (p=0.880). Thus, the addition of nitrate via BRJ to an ISO-C drink does not appear to enhance cognitive function, raising questions about their potential synergistic effect.