Green Tea Supplementation During Resistance Training Minimally Affects Systemic Inflammation and Oxidative Stress Indices in Obese Men

Abstract

Background: It is well known that green tea has antioxidant properties. Accordingly, it is important to investigate the effects of green tea on systemic inflammation and oxidative stress indices in humans during high intensity resistance training, especially in obese men. Objectives: The aim of the present study was to examine the effect of green tea extract supplementation during high intensity resistance exercise training on oxidative stress and systemic inflammation indices in obese men. Methods: Twenty obese men (body mass index ≥ 30) voluntarily participated in the current study and were randomly assigned to groups of green tea and high intensity resistance training (RT) (GR; n = 10) and placebo and high intensity resistance training (PR; n = 10). RT was performed three times a week on non-consecutive days for eight weeks. The training started at 80% of one-repetition maximum (1RM), and training intensity reached to 90 - 95% of 1RM till the end of the eighth week. The GR group consumed a green tea capsule (500 mg) each day during the eight weeks. Blood samples were collected before and after the intervention and were tested for malondialdehyde (MDA) and total antioxidant capacity (TAC). Concentrations of ofinterleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and C-reactive protein (CRP) in plasma were also measured. Results: The results indicated significant (P < 0.05) or near significant improvements in all the measured blood parameters with training, but no further effects (interactions) with ingestion of green tea. Also, we found that there was not any significant relationship between MDA and TAC changes and TNF-alpha and IL-6 in either group after RT intervention and supplementation (P > 0.05). Conclusions: Thus, it can be stated that low-dose green tea supplementation does not influence inflammatory and oxidative stress indices when provided along with exercise training.