Repeated sprint training in hypoxia as a post-surgical rehabilitation strategy: A case study in an elite badminton player

Badminton is a racquet sport that imposes high demands on both aerobic and anaerobic capacity and involves repetitive, high-intensity movements, increasing the risk of non-contact injuries to joints and muscle-tendon units. Returning to sport-specific conditioning after injury, particularly post-surgery, presents challenges for deconditioned athletes seeking to restore aerobic capacity while minimising mechanical stress imposed on the injured parts. This case study evaluated the feasibility of integrating short-term repeated sprint training in hypoxia (RSH) as a supplementary modality within a late-stage post-lower back surgery rehabilitation program to support aerobic reconditioning before return to sport-specific conditioning. An elite men's singles badminton athlete completed 4-week RSH (FiO₂ ~ 16.5%), alongside his regular rehabilitation schedule. The intervention consisted of 20 × 4-s all-out cycling sprints interspersed with 30-56-s recovery, performed once weekly. Post-intervention lactate profiling suggested a rightward shift in the blood lactate curve, with estimated increases of 33% and 10% in power output at the aerobic and anaerobic thresholds, respectively, indicative of aerobic reconditioning. However, the present findings should be interpreted cautiously due to observed stage-to-stage blood lactate variability, single-case design, and concurrent rehabilitation. Overall, the present study supports the feasibility of incorporating hypoxic RSH in late-stage rehabilitation to facilitate return to sport-specific conditioning.