Study reveals how foods modulate oxidative stress after high-intensity training - Video

Pushing your limits in the gym can do wonders for fitness-but it also floods the body with reactive oxygen species (ROS), the unstable molecules responsible for exercise induced oxidative stress. Too much ROS can impair recovery, weaken muscles, and even accelerate aging. Now, a study by University of Vienna researchers, published in Antioxidants, offers new insight into how different foods help the body handle this stress. They found that carbohydrate rich foods protect muscles during exercise, while polyphenol rich foods like berries and pomegranate juice aid recovery after intense workouts-especially in fasted, high intensity conditions.

Oxidative stress occurs when ROS production outpaces the body’s antioxidant defenses. While low levels of ROS help strengthen cells and enhance performance, excess amounts damage tissues and slow recovery. Athletes often turn to foods or supplements rich in antioxidants to balance this effect, but the real world efficacy of such strategies remains debated. To explore this further, the team conducted a randomized controlled trial assessing how carbohydrate and polyphenol rich foods influence ROS generation and antioxidant capacity during exercise.

The researchers enrolled 45 healthy, sedentary women aged 19–33, with 30 completing the full protocol. Participants engaged in resistance circuit high intensity interval training (HIIT) after a 12 hour fast. They were randomly assigned to consume either polyphenol rich foods (blueberries or pomegranate juice) or carbohydrate rich foods (whole grain bread or bread rolls) before training, with water as a control. Blood samples were collected before, during, and after exercise to measure ROS levels and total antioxidant capacity (using FRAP assays).

The results revealed that carbohydrate intake significantly reduced markers of oxidative stress during exercise, stabilizing ROS levels compared to water or polyphenol intake. Carbohydrates appeared to act not by trapping radicals directly, but by reducing the body’s reliance on fat metabolism—thereby limiting mitochondrial ROS production. In contrast, polyphenol rich foods showed their greatest effect during recovery, helping normalize ROS levels faster than carbohydrates. This suggests that while carbohydrates are better for preventing acute oxidative damage, polyphenols support post exercise repair and resilience.

Eating the right food at the right stage of training could optimize both performance and recovery. In practical terms, a balanced strategy—carbs before, polyphenols after—might give athletes the best of both worlds.

REFERENCE: Gassner, M., Bragagna, L., Dasht Bayaz, H. H., Schlosser, L., Lemberg, J., Brem, J., Pignitter, M., Strauss, M., Wagner, K., & König, D. (2025). Acute Impact of Polyphenol-Rich vs. Carbohydrate-Rich Foods and Beverages on Exercise-Induced ROS and FRAP in Healthy Sedentary Female Adults - A Randomized Controlled Trial. Antioxidants, 14(12), 1481. DOI: 10.3390/antiox14121481, https://www.mdpi.com/2076-3921/14/12/1481