Section 5. Intermittent Hypoxia and Sports Training; Effects of Intermittent Hypoxia Training on Peak Performance in Elite Athletes; Use of Intermittent Hypoxia Training in Different Sports; Effects of Intermittent Hypoxia Training in Cytokine Responses to Exercise; Intermittent Hypoxia Exposure and Sleep in Athletes; Effects of Intermittent Hypoxia on Oxygen-Dependent Processes in Skeletal Muscles under Endurance Training;