Acute Nitrate Supplementation in Cyclists

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
Maastricht University Medical Center
ClinicalTrials.gov Identifier:
NCT01384968
First received: June 23, 2011
Last updated: October 16, 2012
Last verified: October 2012
  Purpose

Six days of dietary nitrate (NO3-) supplementation in the form of beetroot juice (~0.5 L•d-1; 5.1-11.2 mmol NO3- •d-1) has been purported to reduce pulmonary oxygen uptake (VO2) during submaximal exercise and increase tolerance to high-intensity workloads. These results suggest that dietary nitrate supplementation has the potential to act as an ergogenic aid. Recently, we assessed submaximal oxygen uptake and 10 km time trial performance after 6 d of dietary nitrate supplementation in trained cyclists. We demonstrated an improvement in time trial performance compared to the nitrate-depleted placebo. However, the minimal dosage and duration of nitrate supplementation that is needed to elicit these performance effects remain largely unknown. Therefore, the purpose of the study is to assess performance capacity following an acute dose of nitrate supplementation consumed 3 h prior to the onset of exercise in trained cyclists. We will test the hypothesis that a single dose (140 mL; ~8 mmol NO3-) of dietary nitrate supplementation in the form of beetroot juice, ingested 3 h prior to exercise will improve time trial performance in trained cyclists compared to a nitrate-depleted placebo.


Condition Intervention
Acute Nitrate Ingestion on Athletic Performance
Dietary Supplement: beetroot juice

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double Blind (Subject, Investigator)
Official Title: Acute Dietary Nitrate Supplementation to Improve Performance in Endurance Trained Athletes

Resource links provided by NLM:


Further study details as provided by Maastricht University Medical Center:

Primary Outcome Measures:
  • Time-trial performance [ Time Frame: Laboratory visits 2, 3 and 4 (each visit separated by ~ 1wk)) ] [ Designated as safety issue: No ]
    Subjects will be asked to visit the laboratory for a total of 4 visits over 4 weeks. During visits 2,3 and 4 time-trial performance will be assessed. Each visit will be separated on average by at least 1 week. Therefore, if subjects have their first visit (max text) in week 1, their time trial performance will be assessed during weeks 2, 3 and 4.


Secondary Outcome Measures:
  • Nitrate and nitrite plasma concentration [ Time Frame: Laboratory visits 3 and 4 (approximately 1 wk apart) ] [ Designated as safety issue: No ]
    During visits 3 and 4 (during the 4 week study), subjects will undergo blood sampling whereby we will assess plasma concentration for nitrate and nitrite. Each visit will be separated by approximately 1 week. Therefore, if subjects enroll in the study during week 1, we will assess nitrate and nitrite during weeks 3 and 4.

  • blood metabolites (glucose, insulin, lactate, free fatty acids) [ Time Frame: Laboratory visits 3 and 4 (approximately 1 wk apart) ] [ Designated as safety issue: No ]
    During visits 3 and 4, subjects will undergo blood sampling whereby we will assess plasma concentration for blood metabolites (glucose, insulin, lactate and free fatty acids). Each visit will be separated by approximately 1 week. Therefore, if subjects enroll in the study during week 1, we will assess blood metabolites during weeks 3 and 4.


Enrollment: 20
Study Start Date: July 2011
Study Completion Date: May 2012
Primary Completion Date: January 2012 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Beetroot juice
beetroot juice (170 mL, 8 mmol nitrate)
Dietary Supplement: beetroot juice
170 mL beetroot juice (Beet It, James White drinks Ltd).
Other Name: Beet It, James White Drinks Ltd.
Placebo Comparator: Nitrate-depleted beetroot juice
140 mL ...0 nitrate. Beetroot juice
Dietary Supplement: beetroot juice
170 mL beetroot juice (Beet It, James White drinks Ltd).
Other Name: Beet It, James White Drinks Ltd.

  Show Detailed Description

  Eligibility

Ages Eligible for Study:   18 Years to 30 Years
Genders Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Healthy
  • Male
  • 18 - 30 years of age
  • Endurance cycling trained (≥3 sessions of endurance exercise per week)
  • VO2 max ≥ 50 ml/kg/min
  • Training history of more than one year of ≥3 sessions of endurance cycling exercise per week
  • BMI <25 kg/m2

Exclusion Criteria:

  • Use of medication
  • Smoking
  • Currently supplementing diet with beetroot juice
  Contacts and Locations
Please refer to this study by its ClinicalTrials.gov identifier: NCT01384968

Locations
Netherlands
Maastricht University
Maastricht, Limburg, Netherlands, 6229ER
Sponsors and Collaborators
Maastricht University Medical Center
Investigators
Study Director: Luc van Loon, Ph.D. Maastricht University
Principal Investigator: Naomi Cermak, Ph.D. Maastricht University
  More Information

Publications:

Responsible Party: Maastricht University Medical Center
ClinicalTrials.gov Identifier: NCT01384968     History of Changes
Other Study ID Numbers: 11-3-033
Study First Received: June 23, 2011
Last Updated: October 16, 2012
Health Authority: Netherlands: The Central Committee on Research Involving Human Subjects (CCMO)

Keywords provided by Maastricht University Medical Center:
nitrite
exercise
cycling

ClinicalTrials.gov processed this record on April 17, 2014