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

Summary

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).

Conditions

• Citrulline
• Nitrate
• Athletes

Interventions

DIETARY_SUPPLEMENT

Citrulline

3 g/day during 9 weeks

DIETARY_SUPPLEMENT

Nitrate

300 mg/day during 9 weeks

DIETARY_SUPPLEMENT

Nitrate plus Citrulline

3 g/day of citrulline and 300 mg/day of nitrate during 9 weeks

DIETARY_SUPPLEMENT

Placebo

3 g/day during 9 weeks

Sponsors & Collaborators

• Universidad de León

  collaborator OTHER

• University of the Basque Country (UPV/EHU)

  collaborator OTHER

• University of Valladolid

  collaborator OTHER

• Burgos Nutrition

  lead OTHER

Principal Investigators

• Jose Burgos Balmaseda, Graduate · University of Leon

Study Design

Allocation

RANDOMIZED

Purpose

OTHER

Masking

SINGLE

Model

CROSSOVER

Eligibility

Min Age

25 Years

Max Age

35 Years

Sex

MALE

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2018-05-01

Primary Completion

2018-08-30

Completion

2021-10-01

Countries

• Spain

Study Locations