Effects of an 8-week aerobic exercise intervention with different intensities on oxidative stress and antioxidant status in Hispanic obese females

Oxidative stress (OS) has been linked to several health conditions such as diabetes, cardiovascular diseases and neurodegenerative diseases. The effects of exercise as a therapeutic approach to modulate OS in Hispanic obese females are still unclear. Purpose: To investigate the effects of an 8-week aerobic exercise intervention with different intensities on oxidative stress and total antioxidant status (TAS) in Hispanic obese females, with measurements at 4 and 8 weeks. Method: Fifty-three inactive obese Hispanic females (mean BMI=34.6 kg/m 2 , aged 35-44) were randomly assigned into three different groups: moderate-low intensity (LT:55% VO2max, n=16), moderate-high intensity (HT:70% VO2max, n=18), and control group (CON: no exercise, n=19). LT and HT groups performed aerobic exercises three times a week at their respective intensities, relative to their body mass (energy expenditure: 13.5 METs·h/w, increased by 4.5 METs·h/w after 4 weeks by adding an additional training session). Blood samples were collected before, at 4 weeks, and after exercise intervention to measure total antioxidant status (TAS) and 8-Hydroxy-2'-deoxyguanosine (8-OHdG). Percent body fat (%BF) and Visceral adipose tissue (VAT) were measured using DEXA scan. Two-way repeated measures ANOVA and post hoc analyses with the Bonferroni correction were used to analyze data. Results: After 4 weeks of intervention, TAS levels significantly increased in both exercise groups, LT (1.76±0.1 mM, Mean±SE → 1.92±0.1, P=0.028) and HT (1.79±0.15→ 1.87±0.1, P=0.039), with no significant difference between groups. After 8 weeks of intervention, both groups presented significant increases in TAS levels: LT (1.76±0.1→ 1.98±0.1, P=0.017) and HT (1.79±0.15→ 1.94±0.2, P=0.026). Additionally, both groups exhibited significant reductions in 8-OHdG: LT (1.92±0.21 ng/mL → 1.84±0.22, P=0.039) and HT (1.90±0.33→ 1.72±0.38, P=0.045), with no significant difference between exercise groups noted. Changes in weight, BMI, and %BF were present in both exercise groups only after 8 weeks of intervention. No significant changes in VAT were exhibited. CON group presented no changes. Conclusion: Results suggest that aerobic exercise interventions within the moderate intensity range of approximately 4 weeks long have the capability of increasing the body’s antioxidant defenses without significant changes in body composition, which suggests that exercise plays a role in the upregulation of TAS. The comparable reduction in %BF in both exercise groups could have mitigated the endogenous production of reactive oxygen species, resulting in similar perceived levels of OS in both HT and LT after the 8 weeks. In addition, since the exercise interventions were within the moderate intensity range, it is plausible that subjects in both exercise groups experienced similar physiological adaptations to the intervention, which could explain the resemblance between TAS and OS levels. Lastly, exercise volume was equal between groups, despite the difference in intensities, which could have promoted comparable adaptations to OS in the subjects. This abstract was presented at the American Physiology Summit 2026 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.