Beetroot-citrulline combo boosted running distance, but didn’t cut exercise induced muscle damage in study

By Hank Schultz

- Last updated on GMT

©Getty Images - JmichL
©Getty Images - JmichL

Related tags beetroot Beetroot juice citrulline Nutrition Sports nutrition

Beetroot nitrates combined with citrulline helped amateur triathletes cover more distance in a standardized running test. It’s the first time these two longtime sports nutrition ingredients have been studied together in this way, the researchers said.

The new study was published in the Biology​.  It was the work of a research team associated with a number of universities in Spain.

Is there a synergy to be found?

The goal of the research was to investigate whether there is a synergistic benefit to combining these two ingredients.  The physiological argument seems to make sense in that nitrate-rich beetroot extract and citrulline, a non-essential endogenous amino acid, have been shown to be nitric oxide (NO) precursors.  Higher NO levels have been associated with greater vasodilation and blood flow with attendant performance benefits.

The researchers designed a four-arm blinded, placebo-controlled study to look into whether this combination could  ameliorate markers of exercise induced muscle damage (EIMD) as well as the anabolic/catabolic hormone ratio. 

 In addition, the authors measured performance via the Cooper test, which is a standardized fitness measurement developed for the US Army. This measures how far a participant can run in 12 minutes.

For subjects, the researchers recruited 32 younger male members of a triathlon club.  They ranged in age from 27 up to 41 and all were lean, with body fat percentages ranging from 7% up to 9%. The subjects were divided into four groups of eight participants each:  placebo, beetroot supplementation, citrulline supplementation or citrulline plus beetroot.  The dosages were 3 grams/day of citrulline and 2.1 grams/day of beetroot extract.

The study extended over nine weeks.  The participants all took part in a defined triathlon training plan  during the study duration and recorded their dietary intakes via a standardized questionnaire.

The four groups had blood drawn for tests at baseline and at the conclusion of the test.  Likewise, they performed one Cooper test at baseline and another at the conclusion of the  study.

Mixed results

The study yielded mixed results.  The combination supplementation did not reduce markers of EIMD, but it did seem to help participants perform better.

The researchers found no detectable difference between the groups when it came to markers of EIMD, which included measurements of urea, creatinine, AST and ALT (measurements of liver function) and others. In the measures of hormone levels, the BR/CIT combination group showed a positive outcome via lower levels of cortisol and better anabolic/catabolic hormone balance.

The most significant effect, however, was found the Cooper test results. Only the BR/CIT combination group showed a significant improvement in this measure.  This group covered an almost 5% greater distance.  

“In conclusion, although the combination of 3 g/day of CIT plus 2.1 g/day of BR (300 mg/day of NO3−) supplementation for 9 weeks did not present any benefit for EIMD, it prevented an increase in cortisol and a decline in T/C compared with placebo or isolated supplementation. Moreover, this combination promoted a better distance covered in the Cooper test after 9 weeks of supplementation,”​ they concluded.

2022, 11​(1), 75;
Long-Term Combined Effects of Citrulline and Nitrate-Rich Beetroot Extract Supplementation on Recovery Status in Trained Male Triathletes: A Randomized, Double-Blind, Placebo-Controlled Trial
Authors: Burgos J, et al.

Related news

Related products

show more

Your expert partner in active nutrition solutions

Your expert partner in active nutrition solutions

Content provided by ADM | 30-Apr-2024 | Case Study

The intersection of the rising plant-based trend and increasing awareness of gut health has opened new opportunities for market success. Consumer demand...

Pycnogenol® for Sport: eNOS and Beyond

Pycnogenol® for Sport: eNOS and Beyond

Content provided by Horphag Research | 12-Apr-2024 | White Paper

Engaging in physical activities immediately triggers a number of physiological responses from our body (1). First, our liver glucose output and adipose...

Sweetening solution for active nutrition

Sweetening solution for active nutrition

Content provided by ADM | 19-Feb-2024 | Case Study

When you add GrainSweet® Liquid Maltodextrin to your active nutrition applications, you get the production efficiencies, clean labels, and clean tastes...

Oats: A Superfood for Sport Nutrition and Health

Oats: A Superfood for Sport Nutrition and Health

Content provided by Fazer Mills | 26-Jan-2024 | White Paper

Oats are a versatile, affordable, and easy to use superfood that can offer many health benefits and a well-balanced nutritional profile for athletes.

Related suppliers

Follow us


View more