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Dietary Nitrate Supplementation and Crossfit Athletes

The Effects of Six-day Dietary Nitrate Supplementation on Strength and Endurance Measurements in Male CrossFit Athletes

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02162927
Enrollment
12
Registered
2014-06-13
Start date
2014-08-31
Completion date
2014-11-30
Last updated
2015-03-04

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Performance

Keywords

muscular strength, muscular endurance, muscular power, rowing, CrossFit, dietary nitrate

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.

Interventions

DIETARY_SUPPLEMENTDietary 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.

DIETARY_SUPPLEMENTPotassium 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.

Sponsors

Florida State University
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Investigator)

Eligibility

Sex/Gender
MALE
Age
20 Years to 35 Years
Healthy volunteers
Yes

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.

Design outcomes

Primary

MeasureTime frameDescription
Muscular StrengthDuring 1 month of studyMuscular Strength will be tested using the isometric and isokinetic strength tests.
Muscular Endurance1 monthEndurance will be tested using the 2000 meter rowing ergometer test and CrossFit circuit known as Fran.
Muscular Power1 monthPower will be measured using the Wingate cycle test.

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026