Abstract
This case study describes the physiological adaptations and performance outcomes of a high-intensity interval training in hypoxia (HITH) intervention in a world-class female Paralympic sprinter during her final preparation for the Paris 2024 Paralympic Games. The participant was a Tier 5, T47 national record-holder in the 400 m. Over an approximately 13-week (≈3-month) period leading up to the Games, she performed HITH on a cycle ergometer, generally twice weekly, in a normobaric hypoxic chamber (FiO
2
14.5%, ∼3,000 m). Performance was assessed via periodic anaerobic power tests and official 400-m race times, and 3-min post-set blood lactate concentration was measured after each HITH session. Throughout the intervention, no clear improvement was observed in maximal or mean power output during laboratory tests, and the athlete's 400-m time at the Paralympic Games was consistent with her 2023 season best, indicating performance maintenance. During the intervention, 3-min post-set blood lactate during repeated-sprint sessions conducted within a broadly consistent framework showed an overall downward trend (Set 1: ∼21 to ∼18 mmol·L⁻¹) while mean and peak power were maintained or slightly increased. The HITH intervention was not associated with enhanced maximal power or a faster 400-m time; the reduced blood lactate response is interpreted cautiously and, because potential mechanisms were not directly measured, is offered as a hypothesis of altered lactate kinetics rather than a demonstrated adaptation.