Dietary Nitrate Supplementation and Crossfit Athletes

NCT ID: NCT02162927

Last Updated: 2015-03-04

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 12 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2014-08-31
• Study Completion Date: 2014-11-30

Brief Summary

In the past, dietary nitrate supplementation has been shown to have clinical benefits in the treatment of cardiovascular issues. More recently, however, the focus of nitrate supplementation has shifted to focus of human performance, and has shown to increase the time to exhaustion during maximal intensity exercise and lower the cost of oxygen consumption during submaximal intensity exercise. Acutely, nitrate supplementation in the form of beetroot juice has been shown to increase strength measurements, as well as increase the time to complete a 2000 meter rowing ergometer test. However, to the author's knowledge, there are no studies that link the relationship between multi-day nitrate supplementation and the rowing test or the nitrate's effect on strength when in the salt form. Additionally, to the author's knowledge, no evidence has been published which relates dietary nitrate supplementation and its effects on a CrossFit circuit workout.

Our central hypothesis is that six days of dietary nitrate supplementation will improve strength, endurance, a power more than a placebo in male CrossFit athletes.

Detailed Description

The purpose of this randomized, double-blind, crossover study is to identify if dietary nitrate supplementation improves strength , endurance, and power measurements in male CrossFit athletes. Specifically, the strength measurements will be taken using isometric and isokinetic tests on the Biodex dynamometer. Endurance will be measured using time trials for a 2000 meter rowing test and the "Fran" CrossFit workout. Finally, power will be analyzed using the Wingate cycle test.

The treatment group will receive 1 serving of f potassium nitrate KNO3- (N) (8 mmols NO3-). The placebo group will receive 1 serving of the nitrate-free placebo (PL) potassium chloride (8 mmol KCl).

The participants will complete two three-day baseline testing, with a six-day supplementation period following each round of baseline testing. Following the first six-day supplementation period, there will be a 10 day washout period before the second baseline testing begins.

Conditions

Performance

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: TREATMENT
• Blinding Strategy: DOUBLE

Study Groups

Potassium Nitrate (N)

This involves 1 serving (2 pills) of potassium nitrate KNO3- (N) (8 mmols NO3-). The supplementation period is six days. This pill must be taken on an empty stomach (2-3 hours after eating) and must be taken about 2-3 hours before exercise.

Group Type: EXPERIMENTAL

Dietary Nitrate

Intervention Type: DIETARY_SUPPLEMENT

This pill must be taken on an empty stomach (2-3 hours after eating) and must be taken about 2-3 hours before exercise.

Potassium Chloride

This involves 1 serving (2 pills) of the nitrate-free placebo (PL) potassium chloride (8 mmol KCl) for a six-day supplementation period. This pill must be taken on an empty stomach (2-3 hours after eating) and must be taken about 2-3 hours before exercise.

Group Type: PLACEBO_COMPARATOR

Potassium Chloride (placebo)

Intervention Type: DIETARY_SUPPLEMENT

This pill must be taken on an empty stomach (2-3 hours after eating) and must be taken about 2-3 hours before exercise.

Interventions

Dietary Nitrate

This pill must be taken on an empty stomach (2-3 hours after eating) and must be taken about 2-3 hours before exercise.

Intervention Type: DIETARY_SUPPLEMENT

Potassium Chloride (placebo)

This pill must be taken on an empty stomach (2-3 hours after eating) and must be taken about 2-3 hours before exercise.

Intervention Type: DIETARY_SUPPLEMENT

Eligibility Criteria

Inclusion Criteria

• College-aged male CrossFit between the ages of 20 and 35 years (yr), a peak maximum oxygen uptake (VO2peak) of at least 50 ml/kg/min will be recruited to participate in this study.

Exclusion Criteria

• Having any thyroid and/or kidney diseases that could affect NO synthesis and/or metabolism, any illness, smoking, taking other medications, injured, not well-trained (as noted by the VO2peak), consuming any other supplements at the time of the study except protein or multivitamin, allergic to any component of the supplement, including tree nuts, in case of potential packaging mixing and contamination. Women and children as well are excluded.

• Minimum Eligible Age: 20 Years
• Maximum Eligible Age: 35 Years
• Eligible Sex: MALE
• Accepts Healthy Volunteers: Yes

Sponsors

Florida State University

OTHER

Sponsor Role: lead

Responsible Party

Michael J. Ormsbee

Assistant Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Michael Ormsbee, PhD

Role: PRINCIPAL_INVESTIGATOR

Florida State University

Samuel J Kramer, BS

Role: STUDY_DIRECTOR

Florida State University

Locations

CrossFit Blackbox

Tallahassee, Florida, United States

Florida State University

Tallahassee, Florida, United States

Countries

United States

Other Identifiers

HSC2014

Identifier Type: -

Identifier Source: org_study_id