The effect was particularly evident for higher intensity, strength-based exercise and following chronic consumption of supplements.
The ‘Nutrients’ published report concludes: “Few studies have been conducted regarding the combination of beetroot juice with other supplements in recent years. Our analysis indicates that there is evidence of its effectiveness, particularly when exercise intensity is higher.”
“However, there appear to be greater benefits when the combination of beetroot juice with another supplement is consumed chronically,” the researchers add.
Nutrition and performance
The importance of optimal nutrition to enhance sporting performance is well-established, with the American College of Sports Medicine (ACSM) emphasising the importance of tailoring nutrients and supplements to specific exercise types. Thus, the use of ergogenic aids within sports has been ever-increasing over recent years.
It is noted that the Australian Institute of Sport (AIS) categorises such supplements depending on the level of evidence demonstrating their impact on athletic performance, with BJ classed as Group A due to its high concentrations of inorganic nitrate.
After the conversion of nitrate to nitrogen oxides within the body following intakes of BJ, the subsequent bioavailability of nitric oxide is improved and thus vasodilation and blood flow to muscle increases. In addition, the presence of beneficial phytonutrients, such as betalains and phenolic compounds, provide significant antioxidant and anti-inflammatory activities to further benefit performance.
As a result, BJ supplementation has been previously reported to benefit aerobic and anaerobic exercise and is of significant interest as an ergogenic aid. Yet, its potential synergistic effect when paired with further supplements to further enhance its effect has not been explored.
Thus, the researchers sought to investigate the actions of BJ supplementation paired with further available nutritional supplements on physical performance.
The present systematic review consisted of searches using the Web of Science and PubMed databases using specific keywords, which were subsequently analysed using exclusive criteria to provide six articles. This resulted in data covering 106 participants across five different countries, with ages ranging from 18 to 64 years old.
Four of the studies included athletes such as football players, triathletes, and runners. The further two studies included physically active individuals. Studies utilised either aerobic tests or strength exercises such as squatting and leg extensions to assess performance parameters.
From the aerobic exercise findings, two studies did not find a benefit following BJ consumption paired with caffeine. On the other hand, one study found a significant increase in aerobic power following BJ and CIT intakes, following chronic consumption of 3g/day of CIT and 2.1g/day of BJ over 9 weeks.
It was noted that the effects of BJ co-supplementation on muscle strength and power proved more effective, with studies highlighting improved performance when BJ was paired with caffeine, NIT, and chronic intakes of CIT.
Regarding conflicting findings following BJ and caffeine intakes for aerobic exercise, the researchers theorise that higher level athletes may require chronic BJ intakes before testing to benefit performance levels.
They summarise: “Therefore, our study shows that the effectiveness of combining BJ with another supplement mainly depends on the duration of the chronic intervention, which is where the greatest benefits have been observed.”
The benefits to strength exercise performance with combined supplement and BJ intakes suggest that the synergistic benefit was particularly apparent for higher intensity exercises.
“Does Co-Supplementation with Beetroot Juice and Other Nutritional Supplements Positively Impact Sports Performance?: A Systematic Review”
by Elida Ferrada-Contreras, Romina Bonomini-Gnutzmann, Carlos Jorquera-Aguilera, Norman MacmiIlan Kuthe, Humberto Peña-Jorquera, and Fernando Rodríguez-Rodríguez