Clinical trial NCT02162927: Dietary Nitrate Supplementation and Crossfit Athletes
Official title: The Effects of Six-day Dietary Nitrate Supplementation on Strength and Endurance Measurements in Male CrossFit Athletes
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Performance
Keywords: muscular strength
muscular endurance
muscular power
rowing
CrossFit
dietary nitrate
Lead sponsor: Florida State University
Sponsor class: OTHER
First posted: 2014-06-13
Enrollment: 12
Sex: MALE
Minimum age (years): 20
Maximum age (years): 35
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: TREATMENT

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.

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.

Primary outcomes:
measure: Muscular Strength
timeFrame: During 1 month of study
measure: Muscular Endurance
timeFrame: 1 month
measure: Muscular Power
timeFrame: 1 month
Secondary outcomes:
Other outcomes:
Locations:
city: Tallahassee
country: United States
facility: CrossFit Blackbox
state: Florida
city: Tallahassee
country: United States
facility: Florida State University
state: Florida
Study officials:
affiliation: Florida State University
name: Michael Ormsbee, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: Florida State University
name: Samuel J Kramer, BS
role: STUDY_DIRECTOR
References: