# Combined high-intensity interval and resistance training improves cardiorespiratory fitness more than high-intensity interval training in young women with overweight/obesity: a randomized controlled trial

PMID: 39588343
Journal: Frontiers in Endocrinology
Published: 2024
Authors: Wang Y, Yang X, Deng J, Wang Z, Yang D, Han Y, Wang H

## Question

Does combining HIIT with resistance training improve body composition, cardiorespiratory fitness, and glycolipid metabolism more than HIIT alone in young women with overweight or obesity?

## Summary

In 38 young women with overweight or obesity who completed an 8-week randomized trial, both HIIT alone and HIIT plus resistance training improved body composition and several fitness and metabolic measures. The combined HIIT plus resistance program produced larger gains in VO2peak, oxygen pulse, vital capacity, and muscle mass, while between-group differences in glucose and lipid markers were not significant.

## Population

- Young women aged 18 to 25 years with overweight or obesity and irregular exercise habits
- Sample size: 38
- Age: About 22 years
- Sex: Female
- Fitness level: Irregular exercise habits
- Health status: Young women with overweight or obesity; BMI about 28.6 to 28.7 kg/m2

## Methodology

- Single-center parallel randomized controlled trial
- 8 weeks plus 1 adaptive training week
- Exercise laboratory and gym at Guangxi Normal University
- Randomized and controlled study design.

## Protocol

- HIIT plus resistance training.
- Modality: mixed.
- Work intervals: 20 seconds.
- Recovery: 10 seconds.
- Sets or repetitions: Each 50-minute session included a 10-minute warm-up, 20 minutes of Tabata-style HIIT, 15 minutes of resistance training, and a 5-minute cooldown. Tabata used 20 seconds high intensity and 10 seconds rest across 4-minute sets; resistance training used 3 sets of 10 repetitions at 70% 1RM.
- Intensity: 85% to 95% HRmax for HIIT and 70% 1RM for resistance training.
- Session duration: 50 minutes.
- Frequency: 3 sessions per week.
- Program length: 8 weeks plus 1 adaptive training week.
- Progression: HIIT intensity increased after week 4; resistance loads adjusted weekly based on 1RM testing.
- HIIT only.
- Modality: mixed.
- Sets or repetitions: Each 50-minute session included a 10-minute warm-up, 35 minutes of Tabata-style HIIT, and a 5-minute cooldown using the same 20-second work and 10-second rest structure.
- Intensity: 85% to 95% HRmax.
- Session duration: 50 minutes.
- Frequency: 3 sessions per week.
- Program length: 8 weeks plus 1 adaptive training week.
- Progression: HIIT intensity increased after week 4.

## Outcomes

### Muscle mass
Status: improved
Muscle mass increased more in the HIIT plus resistance group.

Effect: +2.75%; P value/detail: <0.05; Favours: intervention

### VO2peak
Status: improved
Both groups improved VO2peak, with a larger increase in the HIIT plus resistance group.

Effect: Between-group difference +1.61 mL/kg/min; P value/detail: <0.05; Favours: intervention

### Oxygen pulse
Status: improved
Oxygen pulse improved more with HIIT plus resistance training.

Effect: +0.51 mL/beat between groups; P value/detail: <0.05; Favours: intervention

### Vital capacity
Status: improved
Vital capacity improved more with HIIT plus resistance training.

Effect: +334 mL between groups; P value/detail: <0.05; Favours: intervention

### Glucose and lipids
Status: no clear change
Both groups improved selected glucose and lipid measures, but between-group differences were not significant.

P value/detail: >0.05 between groups; Favours: no_difference

## Practical Insights

- Combining Tabata-style HIIT with resistance training may improve cardiorespiratory fitness while better supporting muscle mass than HIIT alone.
- For app programming, the study supports including resistance elements, but the trial used supervised gym equipment and young women only.
- Equal session duration does not mean equal HIIT exposure when one arm replaces HIIT sets with resistance training.

## Limitations

- Female young-adult sample only.
- Short 8-week intervention.
- No long-term follow-up.
- Diet was not strictly controlled and dietary recall may be biased.
- Small completed sample.

## Safety And Adherence

- Two randomized participants withdrew for personal reasons.
- The article stated most participants did not experience significant adverse reactions during training.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/39588343/) (pubmed)
- [DOI](https://doi.org/10.3389/fendo.2024.1494822) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11586196/) (full text)

## Agent Guidance

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