# Exercise Load Variation at Different Subjective Intensities of High-Intensity Interval Training Using Body Weight

## TL;DR

This study explores how different body-weight exercises at varying perceived intensities affect exercise load in young, healthy men.

## Contribution

The study identifies specific body-weight exercises that achieve high-intensity loads at lower subjective intensities.

## Key findings

- Squats, side lunges, and front lunges reach over 60% of peak VO₂ at 'somewhat hard' intensity.
- Fast walking fails to achieve high-intensity loads even at higher subjective intensities.
- Subjective intensity significantly affects VO₂ during most exercises but not in squats or fast walking.

## Abstract

Introduction: High-intensity interval training (HIIT) using body weight is useful for improving physical function. However, it is unclear how much exercise load can be achieved depending on subjective intensity. This study aims to examine the extent to which body weight exercise at different subjective intensities produces an exercise load according to exercise type in young, healthy adults.

Methods: The participants were 28 young healthy male adults, who performed a progressive exercise load test, and peak oxygen uptake \begin{document} \grave{V}O_2 \end{document} was measured. \begin{document} \grave{V}O_2 \end{document}, heart rate (HR), and exercise frequency at each subjective intensity during HIIT were also measured, compared, and verified.

Results: \begin{document} \grave{V}O_2 \end{document} during high-intensity exercises increased significantly with increasing subjective intensity in squats, side lunges, front lunges, and fast walking (p<0.01). However, in squats and fast walking, no significant differences were found between somewhat hard and hard. More than 60% of peak \begin{document} \grave{V}O_2 \end{document} was achieved in squats, side lunges, and front lunges at a subjective intensity of somewhat hard, but only 60% of peak \begin{document} \grave{V}O_2 \end{document} was achieved in fast walking at a hard subjective intensity.

Conclusions: Exercise modalities under body weight, squats, front lunges, and side lunges can produce high-intensity loads. However, subjective intensity should be “somewhat hard” or higher. The results also suggest that fast walking under body weight is an exercise modality in which high-intensity load, even at a high subjective intensity, is difficult to achieve.