Repeated Sprint Training in Normobaric Hypoxia

This single-blind placebo-controlled designed study was approved by Ankara University Human Research Ethics Committee (2020/277) and conducted in accordance with the Declaration of Helsinki. The participants in normobaric hypoxia (HYP) and placebo (PLA) groups visited the laboratory six times and the control (CON) group visited three times. At the first visit of participants, the aim and the possible outcomes of the research was explained, the familiarization process for cycle ergometer and test/training protocol was performed, and the informed consent forms were obtained. The participants were divided randomly into three groups after the anthropometric measurements and baseline tests were completed so as part of the second visit. The groups were divided as follows; HYP group (n=9) which were exposed to normobaric hypoxia equal to 3420 m (FiO2: 13.5-13.6 %), PLA (n=7) that were exposed to normobaric normoxia equal to 162 m (FiO2: 20.9 %) through wearing the altitude generator mask, and the control group (CON; n=8) which was subjected to only pre and post-test. The determined hypoxic dose for HYP group was directly implemented (setting 9 was equal to 3420 m on used hypoxia generator), and no correction was made for the actual altitude (900 m, Golbasi, Ankara, Türkiye). The normobaric hypoxia and placebo condition was provided by Everest Summit II-Altitude Generator (Hypoxico Hypoxicator, New York, USA). At the 3rd-5th visits, HYP and PLA groups performed 3 repeated sprint training sessions under normobaric hypoxia or normoxia exposure with 48-hour intervals. And the participants visited the laboratory last time for post-test measurements. Each participant visited the laboratory for training sessions and test trials at the same time in the day. In the scope of pre and post-test repeated sprint indices, SpO2 and RPE data were collected. Pre-test and post-test were conducted 72 hours before and 72 hours after the training intervention period in normobaric normoxia condition. Including the testing days, the intervention period lasted 11 days in November 2022. All the experimental processes were conducted in Ankara University Performance Laboratory.

Inclusion criteria

• non-smokers,
• male gender,
• those who do not have any chronic disease,
• do not use any medication,
• do not any training or accommodate above 1500 m altitude within the past 3 months,
• do not have any musculoskeletal injuries within the past 6 months and,
• train at least 3 days in a week.

Exclusion criteria

• Having a chronic or acute condition/disease during the intervention period
• Occurrence of acute respiratory illness or musculoskeletal injury during the intervention period
• Leaving the study voluntarily/on his own account