# Effects of 8-week High-Intensity Interval Training and Moderate-Intensity Continuous Training on Bone Metabolism in Sedentary Young Females

PMID: 35096081
Journal: Journal of Exercise Science and Fitness
Published: 2022 Apr
Authors: Lu M, Li M, Yi L, Li F, Feng L, Ji T, Zang Y, Qiu J

## Question

How do 8 weeks of treadmill HIIT and moderate-intensity continuous training affect bone metabolism, body composition, strength, and aerobic fitness in sedentary young women?

## Summary

In sedentary young women, 8 weeks of treadmill HIIT and moderate continuous training both improved aerobic fitness and some bone-related measures. HIIT produced larger gains in calcaneus ultrasound indexes, vitamin D metabolite, and lower-limb jump performance, with no reported adverse effects.

## Population

- 26 healthy sedentary young women randomized to HIIT or MICT.
- Sample size: 26
- Age: 20-30 years
- Sex: Female
- Fitness level: Sedentary
- Health status: Healthy

## Methodology

- Randomized controlled trial with two active exercise groups
- 8 weeks
- Sports science center treadmill training
- Randomized and controlled study design.

## Protocol

- Treadmill HIIT.
- Modality: Treadmill running.
- Work intervals: 3 min.
- Recovery: 2 min active recovery at 30-40% VO2max.
- Sets or repetitions: 6 intervals.
- Intensity: 80-90% VO2max.
- Session duration: About 45 min including warm-up and cool-down.
- Frequency: 3 sessions/week.
- Program length: 8 weeks.
- Progression: Lower end of intensity range for first 2 weeks, upper end thereafter.
- Moderate-intensity continuous training.
- Modality: Treadmill running.
- Work intervals: 30 min continuous.
- Sets or repetitions: 1 continuous bout.
- Intensity: 60-70% VO2max.
- Session duration: About 45 min including warm-up and cool-down.
- Frequency: 3 sessions/week.
- Program length: 8 weeks.
- Progression: Lower then upper intensity boundary.

## Outcomes

### VO2max
Status: improved
Both HIIT and MICT improved aerobic fitness similarly.

HIIT +18.8%; MICT +17.8%; no between-group difference.

### BMD
Status: improved
Total and lower limb BMD increased in both groups; calcaneus BMD did not clearly change.

Total body BMD +8.5% HIIT and +5.5% MICT; lower limb BMD +4.8% HIIT and +4.4% MICT.

### Calcaneus ultrasound
Status: improved
HIIT improved calcaneus ultrasound indexes more than MICT.

HIIT CBUA +16.0% and CSI +16.7%; between-group superiority reported.

### Jump performance
Status: improved
HIIT produced greater lower-limb jump gains.

Standing long jump +10.3% HIIT vs +3.8% MICT; vertical jump +5.3% vs +2.0%.

## Practical Insights

- Three-minute treadmill HIIT intervals can be tolerated by screened sedentary young women.
- Bone-related outcomes may need longer programs for confident structural interpretation.
- Active recovery and early intensity progression are useful design elements.

## Limitations

- Small sample.
- Short duration relative to bone remodeling timelines.
- Diet and fluid intake not recorded in detail.
- Young healthy female sample limits generalizability.
- Limited bone turnover markers.

## Safety And Adherence

- All participants completed every session.
- The article reports no adverse effects.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/35096081/) (pubmed)
- [DOI](https://doi.org/10.1016/j.jesf.2022.01.001) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8762074/) (full text)

## Agent Guidance

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