Effect of Training in Normobaric Hypoxia on Cardiac Markers

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.

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.

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.

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.

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.

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.

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.