Nitrate Supplementation; Duration

Study Overview
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Brief Summary
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The main aim of the current study will be to find the optimal duration of supplementation to enhance sports performance.

Detailed Description
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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.

Official Title
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The Effect of Nitrate Supplementation on Sports Performance: Duration of Supplementation

Conditions
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Time-trial Performance, Submaximal Exercise Performance, Nitrite, Nitrate

Intervention / Treatment
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* Dietary Supplement: Sodium Nitrate
* Dietary Supplement: Sodium Chloride


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 35 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Sodium Nitrate<br>Dietary Supplement: Sodium nitrate 800 mg of nitrate in sodium nitrate added with water to get a 140 mL solution (BASF, Ludwigshafen, Germany) | Dietary Supplement: Sodium Nitrate<br> <br> |
| Placebo Comparator: Sodium Cloride<br>Dietary Supplement: Sodium chloride 800 mg of sodium chloride added with water to get a 140 mL solution (Frisia Zout BV, Harlingen, The Netherlands) | Dietary Supplement: Sodium Chloride<br> <br> |

What is the study measuring?
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Primary Outcome Measures

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

Secondary Outcome Measures

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

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Performance, Sports, Nitrate