Benefits of 10 weeks of high-intensity interval training and green tea supplementation on cardiovascular risk factors and VO2max in overweight women.

Considered the increasing rate of cardiovascular diseases (CVDs) and a positive relationship between prevalence of CVDs and obesity, the goal of the present study was to investigate the effects of green tea supplement and high-intensity interval training (HIIT) on lipid panel, fibrinogen, and maximal oxygen consumption (VO_2max) in overweight women.

In this randomized placebo-controlled clinical trial, 30 overweight women (age range, 20-30 years), were chosen purposefully and randomly divided into three equal groups (green tea, HIIT + green tea, and HIIT + placebo), and they trained HIIT workouts for 10 weeks (40-m maximal shuttle run) and used 500 mg/daily green tea or placebo tablets. Serum levels of low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglyceride (TG), and plasma level of fibrinogen were assessed before and after the intervention in fasting state. To test the hypothesis of the research, Paired t-test, Wilcoxon signed-rank test, analysis of covariance, and Tukey's post hoc tests were used at the significance level of P ≤ 0.05.

After 10 weeks, TG, LDL, weight, fibrinogen, and body fat percentage decreased in all groups (P ≤ 0.05). Further, HDL (P = 0.012) and VO_2max (P = 0.007) significantly increased in HIIT + green tea and HIIT + placebo groups; while in the green tea group, HDL (P = 0.06) and VO_2max (P = 0.06) showed no significant difference for within group differences. Average between-group variations of all indicators were statistically significant, and they were more meaningfully pronounced in HIIT + green tea group than the other two groups (P ≤ 0.05).

Based on the findings, the combination of HIIT and green tea consumption significantly leads to a reduction in weight, body fat percentage, fibrinogen, TG, and LDL while improves VO_2max and HDL levels rather than green tea consumption or performing training alone, in overweight women. However, it seems that exercise training has a vital role in the improvement of mentioned variables according to percentage changes.