Polyphenols and carbohydrates may modulate exercise-induced oxidative stress through distinct mechanisms: polyphenols via antioxidative properties, and carbohydrates via improved rapidly available energy supply. This randomized controlled trial (RCT) compared the acute effects of polyphenol-rich foods (pomegranate juice, blueberries), carbohydrate-rich foods (whole-grain bread, bread roll) and water control on HIIT-induced changes in ROS and FRAP in thirty healthy females. We conducted an RCT with two parallel intervention cohorts (study arm one: blueberries, whole-grain bread, bread roll, water (control); study arm two: pomegranate juice, water (control)), in which participants completed single-dose intervention days following 12 h fasting. On each intervention day, ROS and FRAP were assessed at baseline, pre-HIIT, post-HIIT and after 15 min recovery. Carbohydrate intake significantly reduced FRAP elevations (−2.16% (p < 0.05)) vs. polyphenols (−2.49% vs. water (p < 0.01) from pre-HIIT to post-HIIT). Furthermore, carbohydrate intake showed a tendency toward attenuating the exercise-induced increase in ROS (−7.75%, p = 0.095, vs. polyphenols from pre-HIIT to post-HIIT), although this did not reach statistical significance. Polyphenol-rich foods accelerated ROS reduction during the 15 min recovery phase (−8.22% (p < 0.01) vs. carbohydrates). No significant differences compared to water were observed from pre-HIIT to post-HIIT (polyphenols: p > 0.05; carbohydrates: p > 0.05) or from post-HIIT to 15 min post-HIIT (polyphenols: p > 0.05; carbohydrates: p > 0.05), which could be expected under fasted HIIT conditions. Overall, carbohydrates mitigated oxidative stress during exercise, whereas polyphenol-rich foods supported short-term post-exercise recovery.