Clinical trial NCT02115893: Nitrate Supplementation; Duration
Official title: The Effect of Nitrate Supplementation on Sports Performance: Duration of Supplementation
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE4
Conditions: Time-trial Performance
Submaximal Exercise Performance
Nitrite
Nitrate
Keywords: Nitrate
Performance
Sports
Lead sponsor: Maastricht University Medical Center
Sponsor class: OTHER
First posted: 2014-04-16
Enrollment: 20
Sex: MALE
Minimum age (years): 18
Maximum age (years): 35
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER

Brief summary: The main aim of the current study will be to find the optimal duration of supplementation to enhance sports performance.

Detailed description: Oral ingestion of nitrate (NO3-) in the form of both nitrate salts and beetroot juice has been shown to significantly lower blood pressure at rest and to also lower pulmonary oxygen uptake during exercise, in addition to improving exercise performance during cycle time trial. However, there has been no consensus on the optimal supplementation protocols, in terms of duration of supplementation to see these metabolic effects. Furthermore, a positive exercise performance effect of nitrate ingestion has primarily been observed in recreational athletes. The potentially ergogenic effects of nitrate in well-trained or elite athletes therefore remain to be fully established. Based on the gaps in current literature, our main goal will be to gain further insight into different aspects of nitrate supplementation to enhance (elite) sports performance. This will be investigated in this study by assessing the effect of an acute vs. chronic supplementation period of sodium nitrate (NaNO3-) on exercise performance.

Eligibility criteria: Inclusion Criteria:

* 18.5 \< BMI \< 25 kg/m2
* Endurance trained cyclists/triathletes (with at least 1 year of competitive cycling experience)
* VO2max ≥ 55 mL/kg/min

Exclusion Criteria:

* Use of medication
* Injury prohibiting them from performing the exercise protocol effectively
* Smoking
* Currently supplementing diet with nitrate
* Lactose intolerance

Primary outcomes:
measure: Time-trial exercise performance
timeFrame: Time trial starts 4 hours after ingestion and ends on average after 15 minutes of cycling (depending on subject's cycling speed)
Secondary outcomes:
measure: Resting blood pressure
timeFrame: 30 min pre-ingestion until 2.5 hours post-ingestion
measure: Plasma nitrate and nitrite levels
timeFrame: 30 min pre-ingestion until 30 min post-time-trial testing
measure: Submaximal exercise performance
timeFrame: starting from 3 hours post-ingestion on testing days until completion of the submaximal exercise
measure: Time-trial exercise performance; power output and heart rate
timeFrame: starting from 4 hours post-ingestion on testing days until completion of the time-trial
Other outcomes:
measure: Baseline characteristics and fitness level assessment
timeFrame: 3 hours during visit 1 (Screening)
Locations:
city: Maastricht
country: Netherlands
facility: Maastricht University Medical Centre+
state: Limburg
city: Maastricht
country: Netherlands
facility: Maastricht University Medical Centre+
state: Limburg
Study officials:
affiliation: Maastricht University
name: Lex B Verdijk, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Wylie LJ, Kelly J, Bailey SJ, Blackwell JR, Skiba PF, Winyard PG, Jeukendrup AE, Vanhatalo A, Jones AM. Beetroot juice and exercise: pharmacodynamic and dose-response relationships. J Appl Physiol (1985). 2013 Aug 1;115(3):325-36. doi: 10.1152/japplphysiol.00372.2013. Epub 2013 May 2.
citation: Cermak NM, Gibala MJ, van Loon LJ. Nitrate supplementation's improvement of 10-km time-trial performance in trained cyclists. Int J Sport Nutr Exerc Metab. 2012 Feb;22(1):64-71. doi: 10.1123/ijsnem.22.1.64.
citation: Bescos R, Sureda A, Tur JA, Pons A. The effect of nitric-oxide-related supplements on human performance. Sports Med. 2012 Feb 1;42(2):99-117. doi: 10.2165/11596860-000000000-00000.