Introduction. Repeated sprint training (RST) has been established as a modality to enhance short-to-medium-term high-intensity short-duration performance. The potential for greater adaptations when conducting RST under real or simulated altitude conditions has been postulated, yet the outcomes have displayed heterogeneity. This study aims to scrutinize the effect of adding normobaric hypoxia during RST on adaptations in high-intensity short-duration performance, as measured by the 30-second Wingate test. Methodology. A systematic review and meta-analysis were conducted, encompassing 13 studies identified from a pool of 493 sourced from PubMed, Sport Discus, and Google Scholar. The RST effects under normobaric hypoxia and normoxia were meta-analyzed separately, followed by a comparative assessment of their pre-to-post training effects. Results. No significant changes in mean power (MP) or peak power (PP) were observed following RST in normoxia (SMD: 0.22, 95% CI: -0.02, 0.45, P = 0.07; and SMD: 0.21, 95% CI: -0.03, 0.46, P = 0.09, respectively). However, relative MP and PP (rMP and rPP) to body weight exhibited significant increases (SMD: 0.41, 95% CI: 0.13, 0.70, P = 0.005; and SMD: 0.31, 95% CI: 0.06, 0.56, P = 0.01). RST in normobaric hypoxia yielded substantial improvements in all four variables (MP: 0.30, 95% CI: 0.07, 0.52; PP: 0.32, 95% CI: 0.09, 0.55; rMP: 0.39, 95% CI: 0.16, 0.62; and rPP: 0.48, 95% CI: 0.25, 0.72; p < 0.01 for all). Notably, no differences were observed in the changes induced by RST in normobaric hypoxia compared to normoxia. Conclusions. The addition of normobaric hypoxia during RST does not affect adaptations in high-intensity short-duration performance achieved with the same training in normoxia. The inclusion of hypoxic stimulus in RST amplifies the internal training load without influencing improvements observed after 6-12 sessions.