EFFECTS OF A SINGLE HEART RATE-CLAMPED CYCLING SESSION UNDER SYSTEMIC HYPOXIA ON RECOVERY OF PHYSICAL AND PSYCHO-PHYSIOLOGICAL RESPONSES FROM EXERCISE-INDUCED FATIGUE

We investigated whether a single heart-rate clamped cycling session under systemic hypoxia affects the recovery of physical and psycho-physiological responses from residual fatigue compared to normoxia. On separate occasions, twelve trained males had countermovement jump height, leg stiffness, and perceptual fatigue assessed daily during a 3-d acute training camp scenario. On days 1 and 3, participants cycled for 60 min at a constant heart rate (80% of ventilatory threshold). On day 2, fatigue was induced through a simulated team game circuit (STGC), followed by a 60-min heart rate clamped cycling bout in either normoxia, hypoxia (simulated altitude ∼3500 m), or no cycling. Compared to baseline, jump height decreased at all timepoints following the STGC (all p < 0.05). Leg stiffness and cycling power output only decreased immediately following the STGC, with a 48% further decrease in cycling power output in hypoxia compared to normoxia (p < 0.05). The well-being questionnaire showed that perceived fatigue, decreased sleep quality, and increased muscle soreness responses occurred on day 3 (p< 0.05). In a pre-fatigued state, a single heart rate-clamped cycling session in hypoxia reduced mechanical output without affecting recovery of physical performance and perceptual measures from residual fatigue induced through team sport activity.