Intermittent Hypoxic Training (IHT) Versus Hyperbaric Oxygen Therapy (HBOT) for Aerobic Performance

Intermittent Hypoxic Training (IHT) Versus Hyperbaric Oxygen Therapy (HBOT) for Aerobic Performance - Prospective Randomized Study

Enhanced physical performance is the goal of all professional and non-professional athletes. There are many intervention methods aim to enhance physical performance from 2 intervention related to change in the environment partial oxygen pressure have been demonstrated to have beneficial effect: IHT and HBOT. This study offers one of the two interventions to athletes with a pre and post intervention objective evaluation of the physiological performance - Maximal exercise test for evaluating VO2MAX and ventilatory thresholds, time to exhaustion, 30 seconds Wingate test, agility test, muscle biopsy, blood tests, brain MRI, cognitive tests and exercise cognitive test. After signing an informed consent form, eligible subjects will be randomized to one of the study groups at a ratio of 1:1. The IHT group will receive three hypoxic guided training sessions per week, according an individualized training protocol, 24 sessions in total. The HBOT group will receive 40 daily hyperbaric sessions, five days per week. Each session will include 90 minutes exposure to 100% oxygen at 2ATA with a five-minute air break every 20 minutes. Three times per week, as the IHT group, the HBOT group will have a guided training session, according an individualized training protocol. Both groups, IHT and HBOT, will have the same relative intensity guided training protocols for 8 weeks, to stimulate the same exercise load. The IHT group will train for 60 minutes, 3 times a week in a normobaric hypoxia environment, at O2 concentration of 15.2% that stimulates a 2500-2600m height. The HBOT group will train for 60 minutes after the HBOT sessions, 3 times per week, in a normobaric normoxic environment Physical performance evaluations will be conducted on 3 different times post interventions - a day last intervention, 3 weeks after and 2 months after - in order to analyze the long term effect of each intervention.

The protocol comprises of 40 consecutive hyperbaric oxygen treatment (HBOT) sessions, 5 sessions per week within a two months' period. The HBOT group will train for 60 minutes after the HBOT sessions, 3 times per week, in a normobaric normoxic environment according to individualized training protocol

The protocol comprises of 24 consecutive Intermittent Hypoxic Training (IHT) sessions, 3 sessions per week within a two months' period. Subjects will train according to individualized training protocol.

Each session will include exposure of 90 minutes to 100% at 2 ATA, with 5 minutes air breaks every 20 minutes

Each session lasts 60 minutes of 15.2% oxygen at 1.0 ATA. Subjects will be training according to individualized training protocol.

The test will be conducted on the SRM high performance ergometer on 105% of the maximal aerobic power

Participants will undergo a muscle biopsy, muscle sample will be analyzed using the Oxygraph (Oroboros Inc, Austria) for oxygen respiratory function, as well as staining for mitochondrial proteins

Cognitive function will be evaluated using the Neurotrax computerized cognitive assessment and the Cambridge Neuropsychological Test Automated Battery (CANTAB).

Participants will be asked to pedal on a bike on workload correlated to 85% of the second ventilatory threshold obtained during the CPET and will simultaneously perform a Stroop test using the EncephalApp Stroop Test application on a tablet.

Whole-brain quantitative perfusion imaging will be performed using Dynamic susceptibility contrast (DSC)-MRI technique

Fractional anisotropy (FA) and Mean diffusivity (MD) will be evaluated using diffusion tensor imaging (DTI) MRI protocol

Inclusion Criteria: Vo2max above 3500 ml or Vo2max/kg above 50 ml/kg Age 18-45 Subjects are active aerobic athletes, training regularly more than 4 exercise sessions per week. Subject willing and able to read, understand and sign an informed consent Exclusion Criteria: Inability to attend scheduled clinic visits and/or comply with the study protocol Active malignancy Active smokers Previous treatment of HBOT for any reason prior to study enrollment. Chest pathology incompatible with pressure changes Major orthopedic injury at the past 3 months Inner ear disease Lung pathology The inability to perform an awake brain MRI Claustrophobia Previous neurologic conditions (e.g., Epilepsy, Brain tumors or s/p neurosurgery etc.) Comorbidities and medications that rule out the subject