# Benefits of 10 weeks of high-intensity interval training and green tea supplementation on cardiovascular risk factors and VO(2max) in overweight women

PMID: 31620178
Journal: Journal of research in medical sciences : the official journal of Isfahan University of Medical Sciences
Published: 2019
Authors: Ghasemi E, Nayebifar S

## Question

Do green tea supplementation and field-style HIIT, separately or together, improve cardiovascular risk factors, body composition, and VO2max in overweight women?

## Summary

In 30 overweight young women, 10 weeks of shuttle-run HIIT with green tea tablets improved lipids, fibrinogen, body composition, and VO2max more than green tea alone or HIIT with placebo for several outcomes. The paper did not describe adverse events, and the intervention mixed exercise with supplementation, so it is not clean HIIT-only evidence.

## Population

- Overweight women aged 20-30 years
- Sample size: 30
- Age: 20-30 years
- Sex: Female
- Fitness level: No regular physical activity history before study
- Health status: Overweight without reported specific disease

## Methodology

- Randomized placebo-controlled clinical trial with three parallel groups
- 10 weeks
- University/community exercise and supplement intervention
- Randomized and controlled study design.

## Protocol

- HIIT plus green tea.
- Modality: 40-m shuttle running.
- Sets or repetitions: Article table describes 40-m shuttle-run progression.
- Intensity: 85-95% HRmax.
- Frequency: 3 days/week.
- Program length: 10 weeks.
- Progression: Progressive table-based protocol.
- HIIT plus placebo / green tea only.
- Modality: HIIT plus placebo used same 40-m shuttle running; green tea-only group had no sport activities.
- Sets or repetitions: Same HIIT protocol for HIIT plus placebo.
- Intensity: 85-95% HRmax for HIIT plus placebo.
- Frequency: 3 days/week for HIIT plus placebo; none for green tea only.
- Program length: 10 weeks.
- Progression: Same table-based progression for HIIT plus placebo.

## Outcomes

### lipids
Status: improved
TG and LDL decreased in all groups; HDL increased significantly only in the two HIIT groups.

Within-group TG, LDL p<=0.05; HDL p=0.012 in both HIIT groups

### VO2max
Status: improved
VO2max increased significantly in HIIT plus green tea and HIIT plus placebo, not green tea alone.

HIIT groups p=0.007; green tea p=0.06

### body composition
Status: improved
Weight and body fat percentage decreased in all groups, with larger changes generally favoring HIIT plus green tea.

Between-group ANCOVA p<=0.05; pairwise results favor HIIT plus green tea for body fat and weight

### safety
Status: unclear
The article did not provide clear adverse-event reporting.

## Practical Insights

- For overweight young women, 3 weekly high-intensity shuttle sessions can improve VO2max over 10 weeks.
- Supplement co-interventions should be separated from workout claims in frontend copy.
- Lack of safety reporting means this is not strong evidence for unsupervised beginner safety.

## Limitations

- Small groups of 10
- Women aged 20-30 only
- Green tea supplementation and diet controls confound exercise-only effects
- Adherence and adverse events not reported in useful detail
- Exact interval timing not clearly available in text outside table

## Safety And Adherence

- The article did not report adverse events, injuries, or symptoms during the 10-week intervention.
- Eligibility and exclusions screened out disease history, medication or antioxidant supplement use, hormonal tablets or supplements, pregnancy, travel, and irregular exercise attendance.
- The article states none of the 30 participants were excluded from the statistical population; HIIT intensity was monitored with a Polar heart-rate watch.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/31620178/) (pubmed)
- [DOI](https://doi.org/10.4103/jrms.JRMS_499_18) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6788331/) (full text)

## Agent Guidance

Preserve the paper-level scope of this note. Do not generalize beyond the population, protocol, measured outcomes, and limitations above.