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.

Study Overview

• Status: Completed
• Conditions: Hypoxia
• Intervention / Treatment: Combination product: Nitrate + Hypoxia; Dietary supplement: Placebo + Hypoxia; Other: Control

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Actual): 30
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Portugal
  • Vila Real, Portugal
    • University of Trás-os-Montes e Alto-Douro

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: HNO: High intensity interval training (HIIT) + nitrate supllementation (NO3-).; Performed 12 high-intensity interval-training (HIIT) sessions during a 4-week period (3 sessions/ week) under normobaric hypoxia conditions (FiO2=~13%, ~3000 m) with NO3- supplement.	Combination product: Nitrate + Hypoxia; 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
Active Comparator: HPL: High intensity interval training (HIIT) + placebo supllementation.; Performed 12 high-intensity interval-training (HIIT) sessions during a 4-week period (3 sessions/ week) under normobaric hypoxia conditions (FiO2=~13%, ~3000 m) with placebo supplement.	Dietary supplement: Placebo + Hypoxia; 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
Placebo Comparator: CON: High intensity interval training (HIIT) + placebo supllementation.; Performed 12 high-intensity interval-training (HIIT) sessions during a 4-week period (3 sessions/ week) under normoxic conditions (FiO2=~20.9%) with placebo supplement.	Other: Control; 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

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Performance adaptations	Time-to-task failure (time sustained)	Moment #1 (48hours pre-intervention) and moment #2 (48hours post-intervention)
Performance adaptations	Time trials (time performed)	Moment #1 (48hours pre-intervention) and moment #2 (48hours post-intervention)
Performance adaptations	VO2 kinetics (time constant and amplitude of fast and slow oxygen components)	Moment #1 (48hours pre-intervention) and moment #2 (48hours post-intervention)
Cardiovascular and neuromuscular adaptations	Maximal oxygen uptake (VO2max: absolute and relative value)	Moment #1 (48hours pre-intervention) and moment #2 (48hours post-intervention)
Cardiovascular and neuromuscular adaptations	Lactate threshold (absolute and percentage of VO2max)	Moment #1 (48hours pre-intervention) and moment #2 (48hours post-intervention)
Cardiovascular and neuromuscular adaptations	Muscular oxygen saturation (SmO2)	Moment #1 (48hours pre-intervention) and moment #2 (48hours post-intervention)
Skeletal muscle adaptations	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	Moment #1 (48hours pre-intervention) and moment #2 (48hours post-intervention)
Skeletal muscle adaptations	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	Moment #1 (48hours pre-intervention) and moment #2 (48hours post-intervention)
Haematological adaptations	Blood pressure (Hmmg), mean arterial pressure (calculated as 1/3 * systolic pressure + 2/3 * diastolic pressure)	Moment #1 (48hours pre-intervention) and moment #2 (48hours post-intervention)
Haematological adaptations	Plasma [NO2-] and [NO3-], erythropoietin (EPO), haemoglobin (Hb) and haematocrit (Hct) - all assays on plasma sample analysed by spectrophometry	Moment #1 (48hours pre-intervention) and moment #2 (48hours post-intervention)
Oxidative stress and antioxidant markers adaptations	Nitrotyrosine, malondialdehyde, ferric-reducing antioxidant power and superoxide dismutase concentrations - all assays on plasma sample analysed by spectrophometry	Moment #1 (48hours pre-intervention) and moment #2 (48hours post-intervention)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Sleep and cardiac autonomic activity adaptations	Sleep duration (minutes)	Moment #1 (2 weeks pre-intervention - baseline) and moment #2 (4 weeks intervention)
Sleep and cardiac autonomic activity adaptations	Sleep efficiency (%)	Moment #1 (2 weeks pre-intervention - baseline) and moment #2 (4 weeks intervention)
Sleep and cardiac autonomic activity adaptations	Wake up time (hours: minutes)	Moment #1 (2 weeks pre-intervention - baseline) and moment #2 (4 weeks intervention)
Sleep and cardiac autonomic activity adaptations	Resting heart rate (bpm)	Moment #1 (2 weeks pre-intervention - baseline) and moment #2 (4 weeks intervention)
Sleep and cardiac autonomic activity adaptations	Heart rate variability (lnRMSSD)	Moment #1 (2 weeks pre-intervention - baseline) and moment #2 (4 weeks intervention)

Collaborators and Investigators

• Sponsor: University of Trás-os-Montes and Alto Douro
• Investigators: Principal Investigator: Ana Sousa, PhD, University of Maia

Study record dates

Study Major Dates

• Study Start (Actual): February 1, 2019
• Primary Completion (Actual): July 22, 2020
• Study Completion (Actual): July 22, 2020

Study Registration Dates

• First Submitted: July 24, 2024
• First Submitted That Met QC Criteria: December 4, 2024
• First Posted (Estimated): December 11, 2024

Study Record Updates

• Last Update Posted (Estimated): December 11, 2024
• Last Update Submitted That Met QC Criteria: December 4, 2024
• Last Verified: December 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Signs and Symptoms, Respiratory; Hypoxia
• Other Study ID Numbers: Hypoxia

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Study overview, participation criteria, study plan, contacts

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No