Repeated sprint training (RST) is a form of high-intensity interval training in which short-duration all-out sprints are interspersed with short recovery periods. High anaerobic demand and increasing aerobic contribution throughout a bout, as sprints are done with very little recovery in-between, may increase production of reactive oxygen species (ROS) which may lead to oxidative stress (OS). Besides being responsible for cellular damage, ROS are also important molecules serving as secondary messengers in skeletal muscle signaling cascades. The main aim of this study was to investigate the effects of running RST on alterations in redox homeostasis (ARH) by monitoring 15-F2t-isoprostane (15-F2t-IsoP) concentration, widely regarded as the “gold standard” marker for the assessment of in vivo lipid peroxidation. Additionally, the study investigated whether muscle and inflammatory status serve as the contributing factor in ARH during the training period. Fifteen male physical education students volunteered to participate in the study. The experimental training program consisted of 2-3 sets of 6-10 straight-line or shuttle 20-meter repeated sprints with departures every 25 seconds and 2-minute inter-set passive recovery. The levels of 15-F2t-IsoP were measured in plasma and 24-hour urine, superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione reductase (GR) in erythrocytes; uric acid (UA), total bilirubin, albumin, transferrin and prolactin in serum, free cortisol and catecholamines in 24-hour urine; creatine kinase, aspartate aminotransferase, lactate dehydrogenase and myoglobin in serum; interleukin 6, C-reactive protein as well as complete blood counts were determined at three time points: after an initial training session (To), after the final training session (T1) and one month after the final training session (T2). The significant changes were observed in repeated measures of plasma 15-F2t-IsoP concentration and GR activity. While the median plasma 15-F2t-IsoP increased by 75%, the median GR decreased by 56%. In 24-hour urine samples, 15-F2t-IsoP levels were 25% greater in post-training, although these increase did not reach statistical significance. Following RST erythrocyte SOD and GPx activities were 11% and 27% lower, although these decreases were nonsignificant. The concentration of extracellular antioxidants, except albumin, remained close to the baseline values throughout the training program. RST program did not affect the marker of muscle damage since there were no significant post-training differences in CK activities. Interleukin-6 was significantly increased, while total leukocyte and neutrophil count also increased although the results were not significant. There were no significant correlations between pre-to-post change in muscle damage and inflammation markers and pre-to-post change in any marker of ARH. Assuming that significant correlation between training volume and post-training 15-F2t-IsoP levels exist and that greater exercise workload elicits greater OS response, the fact that the increase in urinary 15-F2t-IsoP level was much lower than the increase of total training volume from first to the final week and the increase of exercise workload (60%) suggests that RST may cause attenuation of OS.