Volume 32, Issue 1 (3-2025)
RJMS 2025, 32(1): 1-14 |
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Research code: IR.IAU.NAJAFABAD.REC.1402.089
Ethics code: IR.IAU.NAJAFABAD.REC.1402.089
Clinical trials code: IR.IAU.NAJAFABAD.REC.1402.089
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Afshari Fard N, Banaei J, Eftekhari E, Keshavarz S. Investigating the Effect of Continuous and Intermittent Aerobic Exercises with Leukoate Leaf Consumption on Liver Enzymes in Overweight Women. RJMS 2025; 32 (1) :1-14
URL: http://rjms.iums.ac.ir/article-1-8422-en.html
URL: http://rjms.iums.ac.ir/article-1-8422-en.html
1- Student of Sports Science and Physical Education Department, Najaf Abad Branch, Islamic Azad University, Najaf Abad, Iran
2- Assistant Professor, Sports Medicine Research Center, Najaf Abad Branch, Islamic Azad University, Najaf Abad, Iran ,jamshid.banaii@gmil.com
3- Assistant Professor, Sports Medicine Research Center, Najaf Abad Branch, Islamic Azad University, Najaf Abad, Iran
2- Assistant Professor, Sports Medicine Research Center, Najaf Abad Branch, Islamic Azad University, Najaf Abad, Iran ,
3- Assistant Professor, Sports Medicine Research Center, Najaf Abad Branch, Islamic Azad University, Najaf Abad, Iran
Abstract: (1984 Views)
Background & Aims: Overweight and obesity are among the most prevalent chronic health conditions worldwide and are strongly associated with the development of metabolic disorders, cardiovascular diseases, and liver dysfunction. The growing prevalence of obesity has become a major public health concern, particularly among women, due to its contribution to non-alcoholic fatty liver disease (NAFLD) and elevated liver enzyme concentrations. Increased adipose tissue accumulation is recognized as a major factor contributing to hepatic steatosis, oxidative stress, inflammation, and impaired liver function. Elevated serum levels of liver enzymes, including alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP), are commonly used as biomarkers of liver injury and metabolic disturbances.
Lifestyle modifications, particularly regular physical activity and nutritional interventions, are considered effective non-pharmacological strategies for improving liver health. Aerobic exercise has been shown to enhance energy expenditure, improve lipid oxidation, reduce body fat, and alleviate hepatic fat accumulation. Likewise, medicinal plants with antioxidant and anti-inflammatory properties have attracted considerable attention as complementary therapeutic agents. Loquat (Eriobotrya japonica) leaf extract contains abundant bioactive compounds, including flavonoids and phenolic substances, which exhibit hepatoprotective, antioxidant, and anti-inflammatory effects. Although previous studies have independently examined the effects of exercise or loquat supplementation, limited evidence exists regarding the combined effects of continuous aerobic exercise, intermittent aerobic exercise, and loquat leaf consumption on liver enzymes in overweight women. Therefore, the present study aimed to investigate the effects of continuous and intermittent aerobic training, with and without loquat leaf supplementation, on liver enzyme levels in overweight women.
Methods: This study employed a semi-experimental design with pre-test and post-test measurements. The statistical population consisted of overweight women living in Qom, Iran. Ninety participants aged 20–30 years with a body mass index (BMI) between 25 and 30 kg/m² were purposefully selected and randomly assigned to six groups (n = 15 per group): (1) continuous aerobic exercise, (2) intermittent aerobic exercise, (3) loquat leaf supplementation, (4) continuous aerobic exercise combined with loquat leaf supplementation, (5) intermittent aerobic exercise combined with loquat leaf supplementation, and (6) control. Participants completed an eight-week intervention consisting of three training sessions per week. Continuous aerobic exercise involved uninterrupted running at an intensity of 55–60% of heart rate reserve (HRR). Intermittent aerobic exercise consisted of interval running over distances of 100, 200, 300, 400, and 600 meters at an intensity of 80–85% HRR. Exercise intensity was calculated using the Karvonen formula and monitored using Polar heart-rate monitors. The supplementation groups received loquat leaf extract capsules containing 250 mg of loquat leaf extract (LLE). Anthropometric measurements, including body weight, height, body fat percentage, and BMI, were obtained before the intervention. Venous blood samples were collected after an overnight fast before and 48 hours after the final training session. Serum levels of ALT, AST, and ALP were measured using enzymatic methods and commercial laboratory kits.
Data normality was assessed using the Shapiro–Wilk test. Within-group changes were analyzed using paired-sample t-tests, while between-group differences were examined using analysis of covariance (ANCOVA) followed by Tukey’s post hoc test. Statistical significance was set at p < 0.05.
Results: The findings demonstrated that eight weeks of intervention significantly improved liver enzyme profiles in overweight women. Paired-sample t-test results revealed significant reductions in serum AST, ALT, and ALP levels in the continuous aerobic exercise, intermittent aerobic exercise, loquat supplementation, continuous aerobic exercise plus loquat supplementation, and intermittent aerobic exercise plus loquat supplementation groups. No significant changes were observed in the control group. Analysis of covariance indicated significant differences among groups for AST, ALT, and ALP concentrations in the post-test measurements (p < 0.001). Furthermore, Tukey’s post hoc analysis demonstrated that the exercise-plus-supplement groups exhibited significantly greater improvements compared with the control group. Both continuous aerobic exercise combined with loquat supplementation and intermittent aerobic exercise combined with loquat supplementation produced the most pronounced reductions in liver enzyme levels.
The results also indicated that aerobic exercise alone was effective in reducing liver enzyme concentrations, suggesting an improvement in liver function and metabolic health. Continuous aerobic exercise enhanced fat oxidation and energy expenditure, thereby reducing hepatic fat accumulation and improving liver enzyme status. Similarly, intermittent aerobic exercise, performed at higher intensities, appeared to stimulate metabolic adaptations that contributed to enhanced lipid metabolism and reductions in markers of hepatic stress.
The beneficial effects of loquat leaf supplementation may be attributed to its rich antioxidant and anti-inflammatory properties. Bioactive compounds present in loquat leaves have been reported to reduce oxidative stress, inhibit lipid peroxidation, improve antioxidant enzyme activity, and protect hepatocytes from damage. The combination of exercise and loquat supplementation likely produced synergistic effects by simultaneously enhancing metabolic function and reducing oxidative injury within the liver.
Conclusion: The present study provides evidence that both continuous and intermittent aerobic exercise can effectively improve liver enzyme profiles in overweight women. Moreover, combining these exercise modalities with loquat leaf supplementation appears to amplify these beneficial effects. The observed reductions in AST, ALT, and ALP suggest improvements in liver function and a potential decrease in the risk of developing obesity-related liver disorders such as non-alcoholic fatty liver disease.
Several physiological mechanisms may explain these findings. Aerobic exercise increases energy expenditure, enhances mitochondrial function, improves insulin sensitivity, and promotes fatty acid oxidation, thereby reducing hepatic lipid accumulation. Additionally, exercise-induced improvements in body composition and reductions in visceral adiposity may contribute to lower levels of hepatic inflammation and cellular damage. Loquat leaf extract may further support liver health through its antioxidant activity, suppression of reactive oxygen species production, regulation of lipid metabolism, and enhancement of endogenous antioxidant defenses. The combined intervention appears particularly promising as a complementary and non-pharmacological strategy for managing obesity-related liver dysfunction. Given the increasing prevalence of overweight and obesity among women, implementing structured aerobic exercise programs alongside natural antioxidant supplementation may provide a practical and cost-effective approach to improving liver health. In conclusion, eight weeks of continuous aerobic exercise, intermittent aerobic exercise, and loquat leaf supplementation significantly reduced liver enzyme concentrations in overweight women, with the greatest improvements observed when exercise was combined with loquat supplementation. These findings support the use of aerobic exercise and loquat leaf extract as complementary therapeutic approaches for enhancing liver function and preventing obesity-related liver disorders. Future research should investigate longer intervention periods, different dosages of loquat extract, and additional metabolic biomarkers to further clarify the underlying mechanisms and optimize intervention strategies.
Type of Study: Research |
Subject:
Exercise Physiology
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