Purpose: This study aimed to investigate the effect of four weeks of high-intensity interval training (HIIT) combined with lemon supplementation on hematological indices, plasma lipid profile, fat oxidation, and anaerobic and aerobic power in obese women.

Materials and Methods: In this quasi-experimental study, 32 obese women (mean age: 34.62 ± 8.49 years; height: 160.93 ± 4.38 cm; weight: 83.25 ± 10.46 kg; and BMI: 32.10 ± 3.44 kg/m²) were randomly divided into four groups of 8 participants each: 1) Lemon Supplement, 2) High-Intensity Interval Training, 3) Lemon Supplement + High-Intensity Interval Training, and 4) Control. Lemon supplementation was provided in capsule form to the relevant groups. HIIT was conducted for 4 weeks, with 3 sessions per week. Blood samples, body composition assessments, anaerobic power, maximal oxygen consumption (VO2max), and fat oxidation were measured before and 48 hours after the interventions. Statistical analysis was performed using ANCOVA and Bonferroni tests at a significance level of P < 0.05 in SPSS 23 software.

Results: The results showed no significant differences between the groups in hematological indices (RBC, Hb, HCT) (P > 0.05). High-intensity interval training and lemon supplementation significantly improved anaerobic power (P < 0.05). However, significant improvements in body mass index (BMI), total cholesterol, maximal oxygen consumption (VO2max), and resting fat oxidation were observed only in the combined training-supplementation group (P < 0.05).

Conclusion: Based on these findings, four weeks of high-intensity interval training combined with lemon supplementation, without significantly altering hematological indices, effectively impacts body mass index, maximal oxygen consumption, anaerobic power, fat oxidation, and total cholesterol in obese women.