Long-Term Effect of Combined Citrulline and Nitrate-Rich Beetroot Extract Supplementation

November 21, 2021 updated by: Jose Burgos Balmaseda, Burgos Nutrition

Long-term Effect of Combined Citrulline and Nitrate-rich Beetroot Extract Supplementation on Recovery Status in Trained Male Triathletes

Citrulline (CIT) and nitrate-rich beetroot extract (BEET) are widely studied ergogenic aids. However, both supplements have been studied in sort-term and isolated. To the best of the authors' knowledge, the effects of combining both supplements on exercise-induced muscle damage (EIMD) and hormone status have not been investigated to date. Therefore, the main purpose of this study was to determine the effect and degree of potentiation of the long-term (9 weeks) mixture of 3 g/day of CIT plus 2.1 g/day of BEET (300 mg/day of NIT) supplementation on EIMD markers (urea, creatinine, AST, ALT, GGT, LDH and CK) and anabolic/catabolic hormone status (testosterone, cortisol and Testosterone cortisol ratio (T/C)) in male trained triathletes. This study was a double-blind, placebo-controlled trial where participants (n = 32) were randomized into 4 different groups: placebo group (PLG; n = 8), CIT group (CITG; 3 g/day of CIT; n = 8), BEET group (BEETG; 2.1 g/day of BEET (300 mg/day of NIT) ; n = 8) and CIT-NIT group (CIT-BEETG; 3 g/day of CIT plus 2.1 g/day of BEET (300 mg/day of NIT); n = 8). Blood samples were collected from all participants at baseline (T1) and after 9 weeks of supplementation (T2).

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Triathlon is an endurance sport in which athletes compete sequentially in swimming, cycling and running. Prolonged and strenuous training combined with insufficient recovery can produce muscular and metabolic stress, resulting in structural and functional damage to the musculoskeletal system leading to a fatigue status, which results in decreased athletic performance. As a consequence of this type of combined exercise, there are also alterations in biochemical markers of exercise-induced muscle damage (EIMD) as well as anabolic/catabolic hormones. Therefore, their analysis is useful in determining the balance between training loads and recovery. In this sense, it is essential to include different strategies to reduce or prevent EIMD, which delay or reduce muscle fatigue and improve sports performance. One of these strategies is the use of different ergogenic aids such as L-citrulline (CIT) and nitrates (NIT) which have been proposed as both substances produce an increase in nitric oxide (NO).

Study Type

Interventional

Enrollment (Actual)

32

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Spain
    • Castilla Y León
      • León, Castilla Y León, Spain, 24004
        • University of León

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

25 years to 35 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Male

Description

Inclusion Criteria:

  • Males between 25 and 35 years old
  • Triathletes
  • With at least 5 years of experience
  • Without any disease
  • Non smokers
  • Non drinkers of alcohol
  • Not to take any other medications or stimulant substances during the study
  • 2 weeks without taking other nutritional supplements

Exclusion Criteria:

  • Exclusion criteria:
  • Men under 25 and over 35 years of age.
  • Non triathletes
  • Less than 5 years of experience
  • With any disease
  • Smokers
  • Alcohol drinkers

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: Placebo
8 subjects took 3 g/kg/day of placebo during 9 weeks
Dietary supplement: Placebo
3 g/day during 9 weeks
Other Names:
  • Cellulose
Active Comparator: Nitrate
8 subjects took 3 g/kg/day of nitrate during 9 weeks
Dietary supplement: Nitrate
300 mg/day during 9 weeks
Active Comparator: Citrulline
8 subjects took 3 g/kg/day of citrulline during 9 weeks
Dietary supplement: Citrulline
3 g/day during 9 weeks
Active Comparator: Nitrate plus Citrulline
8 subjects took 3 g/kg/day of nitrate plus citrulline during 9 weeks
Dietary supplement: Nitrate plus Citrulline
3 g/day of citrulline and 300 mg/day of nitrate during 9 weeks

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Cortisol
Time Frame: 9 weeks
μg/dL
9 weeks
Testosterone
Time Frame: 9 weeks
ng/mL
9 weeks
Testosterone to cortisol ratio
Time Frame: 9 weeks
ng/mL
9 weeks
Urea
Time Frame: 9 weeks
mg/dl
9 weeks
Creatinine
Time Frame: 9 weeks
mg/dl
9 weeks
AST
Time Frame: 9 weeks
U/L
9 weeks
ALT
Time Frame: 9 weeks
U/L
9 weeks
GGT
Time Frame: 9 weeks
U/L
9 weeks
LDH
Time Frame: 9 weeks
U/L
9 weeks
CK
Time Frame: 9 weeks
U/L
9 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Burgos Nutrition

Collaborators

University of the Basque Country (UPV/EHU)
Universidad de León
University of Valladolid

Investigators

  • Principal Investigator: Jose Burgos Balmaseda, Graduate, University of León

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

May 1, 2018

Primary Completion (Actual)

August 30, 2018

Study Completion (Actual)

October 1, 2021

Study Registration Dates

First Submitted

October 2, 2021

First Submitted That Met QC Criteria

November 21, 2021

First Posted (Actual)

December 3, 2021

Study Record Updates

Last Update Posted (Actual)

December 3, 2021

Last Update Submitted That Met QC Criteria

November 21, 2021

Last Verified

November 1, 2021

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • ULE-020-2020

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

No

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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