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Completed

NCT Number: NCT06727656

Exercise in Hypoxia and Nitrate Supplementation in Athletes: is the Whole Greater Than the Sum of Its Parts?

Determine the combined effect of training in hypoxia and nitrate supplementation on the performance and health of athletes at sea-level and altitude conditions.

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Key information

Conditions

Hypoxia Pathological Conditions, Signs and Symptoms Signs and Symptoms Signs and Symptoms, Respiratory

Age range

18 year–45 year

Sex eligibility

Male

Study type

Interventional

Phase

Not applicable

Primary location

University of Trás-os-Montes e Alto-Douro

Vila Real, Portugal

About this study

Determine the combined effect of training in hypoxia and nitrate supplementation on the performance and health of athletes at sea-level and altitude conditions. It is hypothesized that the combined effect of these interventions will promote an additional performance and health improvement in this population at sea-level and altitude conditions, compared with the single effect.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • trained male subjects, regularly involved in competitive running, cycling and/ or triathlon events (4-5 times per week) in the past five years

Exclusion criteria

  • smoking or other chronic issues
  • using medication or dietary supplements in the last 3 months, or during the duration of the study
  • being exposed to altitude (≥2000 m) in the last 3 months

Treatment and study plan

Nitrate + Hypoxia

Combination Product

The combined effect of nitrate supplementation and hypoxia training on both performance and health at sea-level and altitude conditions.

Other names: Beetroot Juice + Atitude training

Placebo + Hypoxia

Dietary Supplement

The combined effect of placebo supplementation and hypoxia training on both performance and health at sea-level and altitude conditions.

Other names: Placebo Juice + Atitude training

Control

Other

The combined effect of placebo supplementation and normoxia training on both performance and health at sea-level and altitude conditions.

Other names: Placebo Juice + Normoxia training

Primary outcomes

  1. Performance adaptations

    Time frame: Moment #1 (48hours pre-intervention) and moment #2 (48hours post-intervention)

    Time-to-task failure (time sustained)

  2. Performance adaptations

    Time frame: Moment #1 (48hours pre-intervention) and moment #2 (48hours post-intervention)

    Time trials (time performed)

  3. Performance adaptations

    Time frame: Moment #1 (48hours pre-intervention) and moment #2 (48hours post-intervention)

    VO2 kinetics (time constant and amplitude of fast and slow oxygen components)

  4. Cardiovascular and neuromuscular adaptations

    Time frame: Moment #1 (48hours pre-intervention) and moment #2 (48hours post-intervention)

    Maximal oxygen uptake (VO2max: absolute and relative value)

  5. Cardiovascular and neuromuscular adaptations

    Time frame: Moment #1 (48hours pre-intervention) and moment #2 (48hours post-intervention)

    Lactate threshold (absolute and percentage of VO2max)

  6. Cardiovascular and neuromuscular adaptations

    Time frame: Moment #1 (48hours pre-intervention) and moment #2 (48hours post-intervention)

    Muscular oxygen saturation (SmO2)

  7. Skeletal muscle adaptations

    Time frame: Moment #1 (48hours pre-intervention) and moment #2 (48hours post-intervention)

    Oxidative enzyme activity (cytochrome oxidase subunit IV), citrate synthase, transcription factors (HIF-1alpha and PGC-1alpha) and GLUT4 - assessed through standard enzymatic fluorometric assay and western bllotting

  8. Skeletal muscle adaptations

    Time frame: Moment #1 (48hours pre-intervention) and moment #2 (48hours post-intervention)

    Mitochondrial and capillary density, capillary-to-fibre ratio and fibre cross-section area - cryosections cut with a cryostat and further samples analysed by fluorescence microscopy

  9. Haematological adaptations

    Time frame: Moment #1 (48hours pre-intervention) and moment #2 (48hours post-intervention)

    Blood pressure (Hmmg), mean arterial pressure (calculated as 1/3 * systolic pressure + 2/3 * diastolic pressure)

  10. Haematological adaptations

    Time frame: Moment #1 (48hours pre-intervention) and moment #2 (48hours post-intervention)

    Plasma [NO2-] and [NO3-], erythropoietin (EPO), haemoglobin (Hb) and haematocrit (Hct) - all assays on plasma sample analysed by spectrophometry

  11. Oxidative stress and antioxidant markers adaptations

    Time frame: Moment #1 (48hours pre-intervention) and moment #2 (48hours post-intervention)

    Nitrotyrosine, malondialdehyde, ferric-reducing antioxidant power and superoxide dismutase concentrations - all assays on plasma sample analysed by spectrophometry

Secondary outcomes

  1. Sleep and cardiac autonomic activity adaptations

    Time frame: Moment #1 (2 weeks pre-intervention - baseline) and moment #2 (4 weeks intervention)

    Sleep duration (minutes)

  2. Sleep and cardiac autonomic activity adaptations

    Time frame: Moment #1 (2 weeks pre-intervention - baseline) and moment #2 (4 weeks intervention)

    Sleep efficiency (%)

  3. Sleep and cardiac autonomic activity adaptations

    Time frame: Moment #1 (2 weeks pre-intervention - baseline) and moment #2 (4 weeks intervention)

    Wake up time (hours: minutes)

  4. Sleep and cardiac autonomic activity adaptations

    Time frame: Moment #1 (2 weeks pre-intervention - baseline) and moment #2 (4 weeks intervention)

    Resting heart rate (bpm)

  5. Sleep and cardiac autonomic activity adaptations

    Time frame: Moment #1 (2 weeks pre-intervention - baseline) and moment #2 (4 weeks intervention)

    Heart rate variability (lnRMSSD)

Sponsors and collaborators

Lead sponsor

University of Trás-os-Montes and Alto Douro

Other

Registry information

Important dates

Study start
2019
Primary completion
2020
Study completion
2020
First posted
Dec 11, 2024
Registry last updated
Dec 11, 2024

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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