Biochemical Effects of Long-Term Exercise on Oxidative Stress and Antioxidant Markers in Adolescent Female Athletes

Adolescence is a critical period where exercise-induced oxidative stress is modulated by both training adaptations and hormonal changes, particularly the antioxidant effects of estrogen in females. However, data on how adolescent female athletes respond to long-term exercise remain limited. The aim of this study was to examine oxidative stress levels and some antioxidant defense parameters in adolescent female athletes who train regularly.

The study included 20 adolescent female basketball players (16.65 ± 0.67 years; 165.50 ± 0.06 cm; 59.75 ± 5.50 kg) with at least three years of training experience and 20 non-athlete adolescent female participants (16.80 ± 0.69 years; 159.95 ± 0.04 cm; 60.15 ± 4.23 kg). Malondialdehyde (MDA), glutathione (GSH), and catalase (CAT) levels were analyzed by a spectrophotometric method using a UV/VIS spectrophotometer in blood samples taken from all participants, and the data were compared between the groups.

The results showed that MDA levels were significantly lower in the athlete group (p < 0.01; d = 4.78). In addition, CAT activity was significantly higher in athletes compared to non-athletes (p < 0.01; d = 7.81). However, no significant difference was observed in GSH levels between the groups (p > 0.05; d = 0.15). A strong negative correlation was found between MDA and CAT (r = -0.900).

These findings suggest that prolonged exercise reduces oxidative stress and enhances catalase-mediated antioxidant defense in adolescent women. Increased CAT activity and decreased MDA levels support this effect, while stable GSH levels point to the role of compensatory mechanisms.