Effect of Training in Normobaric Hypoxia on Cardiac Markers

Summary

The goal of this study is to determine changes in the concentration of cardiac biomarkers in blood in response to a single bout of exercise performed until volitional exhaustion under hypoxic conditions, and in response to endurance and resistance training in athletes in hypoxia. The investigators hypothesize that: (1) adverse changes in the myocardium may occur during exercise in acute normobaric hypoxia, but they are at least partially reversed by adaptive alterations induced by training in hypoxia; (2) this response is identical in athletes with eccentric cardiac hypertrophy and those with concentric cardiac hypertrophy.

The study consists of three stages. Stage 1 (completed) has examine changes in the blood levels of cardiac biomarkers in response to a single bout of exercise performed until volitional exhaustion in normoxia and during different levels of hypoxia (2000, 3000m). This stage has examined men aged 20-40 years involved in competitive cycling and triathlon, and untrained, healthy men.

Stage 2 of the study will examine changes in the blood levels of cardiac biomarkers in cyclists (aged 20-40) in response to a 3-week endurance training in hypoxia and to passive prolonged exposure (11 to 12 hours a day) to a simulated altitude of 3000m. Stage 3 will examine changes in blood levels of cardiac biomarkers in response to a 3-week resistance training in hypoxia (3000m). This stage of the study will involve men aged 20-40 training in strength sports.

The project will help clarify the effects of hypoxia on the physiological state of the heart in athletes with eccentric or concentric cardiac hypertrophy, as well as determine the differences between competitive athletes vs. untrained, healthy men in the response to hypoxia. The findings may be used in planning and controlling the training process in both strength and endurance disciplines. The research to be conducted in the project is basic research, but it may have a certain applicative aspect.

Conditions

• Healthy
• Heart Disease

Interventions

OTHER

Impact of Normobaric Hypoxia on Cardiac Biomarkers in trained men

The intervention will consist of three series differing in terms of simulated altitude: S1 (normoxia), S2 (2000 m a.s.l.), and S3 (3000 m a.s.l.). Each research series will consist of one day of the measurements. All participants will perform two ergocycle tests (the graded exercise test GXT and constant-workload exercise test CXT at the individual lactate threshold workload (WRLT) until volitional exhaustion) with 10 minutes of active recovery break in different environment (S1, S2, S3- 3000). The order of the series will be randomized across all participants. The fraction of inspired oxygen (FIO2) will depend on the series and will be as follows: S1 (normoxia) = 20.9%; S2 (2000 m a.s.l.) = 16,5%; S3 (3000 m a.s.l.) = 14.4%. The hypoxic environment will be maintained using AirZone climate technology (AirSport). Between the series, there will be a one-week active rest break excluding exposure to hypoxia and performance of high-intensity exercise.

OTHER

Effects of Hypoxic Endurance Training on Cardiac Biomarkers in the IHT group

The participants in IHT group will live in normoxic conditions, but part of their training will be performed in normobaric hypoxia in a hypoxic chamber. The experiment will consist of two series of testing: S1 (baseline) and S2 (after 3 weeks of training and 3 days of rest). All participants will perform the same testing protocol as in stage 1-albeit in a normoxic environment and after 72h of rest, all testing procedures will be repeated in a hypoxic environment.

OTHER

Effects of Hypoxic Strength Training on Cardiac Biomarkers in the NRT group

The participants in the NRT group will perform resistance training in normoxia. The experiment will consist of two series of testing (S1 and S2), performed in a laboratory. S1 will involve baseline testing, while S2 will be performed after three weeks of training after 3 days of rest. Each research series will consist of three measurement days. The testing protocol and blood sampling will be the same as in the first and second stages of the research. After next 72h of rest, all participants will have their muscle strength assessed using the one-repetition maximum (1RM) test in normoxia environment. The tests will be conducted in two exercises: a barbell bench press and a barbell squat.

OTHER

Impact of Normobaric Hypoxia on Cardiac Biomarkers in untrained men

The intervention will consist of three series differing in terms of simulated altitude: S1 (normoxia), S2 (2000 m a.s.l.), and S3 (3000 m a.s.l.). Each research series will consist of one day of the measurements. All participants will perform two ergocycle tests (the graded exercise test GXT and constant-workload exercise test CXT at the individual lactate threshold workload (WRLT) until volitional exhaustion) with 10 minutes of active recovery break in different environment (S1, S2, S3- 3000). The order of the series will be randomized across all participants. The fraction of inspired oxygen (FIO2) will depend on the series and will be as follows: S1 (normoxia) = 20.9%; S2 (2000 m a.s.l.) = 16,5%; S3 (3000 m a.s.l.) = 14.4%. The hypoxic environment will be maintained using AirZone climate technology (AirSport). Between the series, there will be a one-week active rest break excluding exposure to hypoxia and performance of high-intensity exercise.

OTHER

Effects of Hypoxic Endurance Training on Cardiac Biomarkers in the LHTL group

The participants from the LHTL group will be exposed to normobaric hypoxia (FIO2 = 14.4%, corresponding to an altitude of 3000 m a.s.l.) in a hotel room for 11 to 12 hours a day (evenings and nights). Participants in this group will perform interval training under normoxic conditions. The experiment will consist of two series of testing: S1 (baseline) and S2 (after 3 weeks of training and 3 days of rest). All participants will perform the same testing protocol as in stage 1-albeit in a normoxic environment and after 72h of rest, all testing procedures will be repeated in a hypoxic environment.

OTHER

Effects of Hypoxic Endurance Training on Cardiac Biomarkers in the Control group

The participants in the C group will live and train in normoxic conditions. The experiment will consist of two series of testing: S1 (baseline) and S2 (after 3 weeks of training and 3 days of rest). All participants will perform the same testing protocol as in stage 1-albeit in a normoxic environment and after 72h of rest, all testing procedures will be repeated in a hypoxic environment.

OTHER

Effects of Hypoxic Strength Training on Cardiac Biomarkers in the HRT group

The participants in the HRT group will perform resistance training in normobaric hypoxia (FIO2 = 14.4%, 3000 m a.s.l.). The experiment will consist of two series of testing (S1 and S2), performed in a laboratory. S1 will involve baseline testing, while S2 will be performed after three weeks of training after 3 days of rest. Each research series will consist of three measurement days. The testing protocol and blood sampling will be the same as in the first and second stages of the research. After next 72h of rest, all participants will have their muscle strength assessed using the one-repetition maximum (1RM) test in normoxia environment. The tests will be conducted in two exercises: a barbell bench press and a barbell squat.

Sponsors & Collaborators

• Józef Piłsudski University of Physical Education

  lead OTHER

Principal Investigators

• Miłosz Czuba, Prof. · Józef Piłsudski University of Physical Education in Warsaw, Poland

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

20 Years

Max Age

40 Years

Sex

MALE

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2024-06-01

Primary Completion

2026-12-30

Completion

2026-12-30

Countries

• Poland

Study Locations