Changes in Aerobic Performance Following Intensive Interval and Repeated Sprint Training in Volleyball and Basketball Athletes

This study examined changes in aerobic performance following a six-week high-intensity interval training (HIIT) combined with repeated sprint training (RST) intervention in volleyball and basketball athletes under field conditions. Using a quasi-experimental single-group pre-test–post-test design, twenty-nine regularly training male athletes volunteered to participate (volleyball: n = 14; basketball: n = 15). The intervention was implemented in addition to routine sport-specific training and consisted of high-intensity interval running combined with repeated maximal straight-line sprints performed with short recovery intervals. Aerobic performance was assessed before and after the intervention using the 20 m shuttle run test. As the data did not meet normality assumptions, pre–post changes were analyzed using the Wilcoxon signed-rank test, and the magnitude of change was quantified using effect size (r). The results demonstrated significant improvements in post-test shuttle run performance compared with baseline in both volleyball and basketball players (p < 0.05), with large effect sizes observed in each group (r = 0.89). These findings indicate that integrating HIIT and RST within a relatively short training period is associated with meaningful improvements in aerobic-related field performance, which may support tempo maintenance and recovery between repeated high-intensity actions in team sports. From a practical perspective, incorporating 2–3 HIIT/RST sessions per week during congested in-season phases may represent a time-efficient strategy to enhance aerobic fitness in volleyball and basketball athletes.