Nitrate Supplementation; Duration

Phase 4

Completed

• Conditions: Submaximal Exercise Performance; Nitrite; Time-trial Performance; Nitrate
• Interventions: Dietary Supplement: Sodium Nitrate; Dietary Supplement: Sodium Chloride

• Registration Number: NCT02115893
• Lead Sponsor: Maastricht University Medical Center

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.

Study Timeline

• Study Start: 2014-04
• Study First Submitted: 2014-04-10
• Study First Submitted QC: 2014-04-14
• Study First Posted: 2014-04-16
• Status Verified: 2014-10
• Primary Completion: 2014-11
• Study Completion: 2015-03
• Last Update Submitted: 2016-03-15
• Last Update Posted: 2016-03-16

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Male
• Target Recruitment: 20

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Sodium Nitrate	Sodium Nitrate	Dietary Supplement: Sodium nitrate 800 mg of nitrate in sodium nitrate added with water to get a 140 mL solution (BASF, Ludwigshafen, Germany)
Sodium Cloride	Sodium Chloride	Dietary Supplement: Sodium chloride 800 mg of sodium chloride added with water to get a 140 mL solution (Frisia Zout BV, Harlingen, The Netherlands)

Primary Outcome Measures

Name	Time	Method
Time-trial exercise performance	Time trial starts 4 hours after ingestion and ends on average after 15 minutes of cycling (depending on subject's cycling speed)	The primary outcome measure will be the time to complete the time-trial following dietary nitrate or placebo ingestion

Secondary Outcome Measures

Name	Time	Method
Plasma nitrate and nitrite levels	30 min pre-ingestion until 30 min post-time-trial testing	Plasma nitrate and nitrite levels following ingestion of dietary nitrate
Resting blood pressure	30 min pre-ingestion until 2.5 hours post-ingestion	Resting blood pressure measures following ingestion of dietary nitrate
Time-trial exercise performance; power output and heart rate	starting from 4 hours post-ingestion on testing days until completion of the time-trial	Power output and heart rate during the time-trial exercise
Submaximal exercise performance	starting from 3 hours post-ingestion on testing days until completion of the submaximal exercise	Oxygen consumption CO2 production and heart rate during submaximal exercise

Trial Locations

Locations (1)

Maastricht University Medical Centre+; 🇳🇱 Maastricht, Limburg, Netherlands