Aerobic training performed at ventilatory threshold improves liver enzymes and lipid profile related to non-alcoholic fatty liver disease in adolescents with obesity

Abstract

Background:

Despite the positive effects of high-intensity training on weight management and health-related outcomes, it is postulated that high-intensity training may also induce oxidative stress, increasing hepatic damage.

Aim:

The aim of this study was to compare the effects of low versus high-intensity training on biomarkers related to non-alcoholic fatty liver disease (NAFLD) in adolescents with obesity.

Methods:

For this study 107 adolescents (15 ± 1 years) with obesity (BMI = 34.7 ± 4.1 kg/m²) were randomized into High-Intensity Training (HIT, n = 31), Low-Intensity Training (LIT, n = 31) or Control Group (CG, n = 45). Adolescents from HIT and LIT received nutritional, psychological and clinical counseling. Blood lipids, Castelli risk index, glucose, insulin and hepatic enzymes were measured at baseline and after 12 weeks.

Results:

Castelli risk index 1 was reduced in all groups (p < 0.001) with moderate effect size (d) for HIT (d = 0.62) and LIT (d = 0.66). Castelli risk index 2 also decreased (p < 0.001 for all groups; HIT d = 0.65; LIT d = 0.79). High-density lipoprotein increased in all groups (d = 0.25 and d = 0.18 in HIT and LIT), while alanine aminotransferase tended to reduce (p = 0.062) in HIT (d = 0.34) and LIT (d = 0.73) and aspartate aminotransferase decreased (p = 0.024) in both HIT (d = 0.24) and LIT (d = 0.45). There were no changes in glucose, insulin and insulin resistance.

Conclusion:

Both high and low-intensity training improved biomarkers related to NAFLD. Thus, high-intensity training can be a safe and effective alternative to prevent and treat NAFLD in adolescents with obesity.