# Comparative Effects of High-Intensity Interval Training and Low-Intensity Steady-State Exercise on Anthropometric Outcomes and Psychophysical Well-Being: A Pilot Study

PMID: 41900495
Journal: Journal of functional morphology and kinesiology
Published: 2026 Feb 20
Authors: Di Domenico F, Esposito G, Aliberti S, Ceruso R, Raiola G

## Question

How do supervised HIIT and LISS compare over 12 weeks for anthropometry and post-intervention psychophysical perceptions in active adults?

## Summary

In a 12-week supervised real-world pilot, physically active adults doing HIIT and those doing low-intensity steady-state exercise both improved body mass, BMI, fat mass, and waist/hip measures. HIIT appeared better for preserving or slightly increasing muscle mass and perceived performance, while LISS participants reported higher psychological well-being.

## Population

- Twenty-four physically active adults in supervised personal training.
- Sample size: 24
- Age: 20-35 years
- Sex: Men and women
- Fitness level: Physically active; supervised training at least 12 months
- Health status: No contraindications to moderate/high intensity exercise

## Methodology

- Pilot quasi-experimental parallel-group study
- 12 weeks
- Real-world supervised personal training facility
- Controlled study design.

## Protocol

- Supervised circuit HIIT.
- Modality: Multi-joint circuit.
- Work intervals: 30 seconds.
- Recovery: 30 seconds active recovery; 2 minutes passive recovery between rounds.
- Sets or repetitions: 6 exercises x 4 rounds.
- Intensity: 85-95% HRmax during work intervals; 80-95% HRmax overall.
- Session duration: 50-60 minutes.
- Frequency: 3 sessions/week.
- Program length: 12 weeks.
- Progression: Execution intensity, HR-zone duration, and exercise complexity increased while timing stayed constant.
- LISS.
- Modality: Continuous treadmill, elliptical, stationary bike, or stair climber.
- Sets or repetitions: 40 minutes continuous aerobic work.
- Intensity: 60-70% HRmax during main set.
- Session duration: 50 minutes.
- Frequency: 3 sessions/week.
- Program length: 12 weeks.
- Progression: Speed or incline adjusted to maintain HR zone.

## Outcomes

### Fat mass
Status: improved
Both HIIT and LISS improved body mass, BMI, fat mass, and waist/hip measures with no primary endpoint between-group difference.

Time effects p<0.001; no between-group difference for primary endpoint.

### Muscle mass
Status: improved
Muscle mass preservation or slight gain favored HIIT.

Group x time p<0.001; HIIT trend +0.63 kg p=0.06, d=0.81.

### Perceptions
Status: mixed
LISS had higher psychological well-being, while HIIT had greater perceived performance improvement.

Psychological well-being p=0.002; performance p=0.002 to <0.001.

## Practical Insights

- HIIT and LISS can both be presented as viable supervised body-composition options for active adults.
- HIIT programming may emphasize performance and muscle-preservation goals; LISS may fit users prioritizing psychological well-being.

## Limitations

- Small pilot sample.
- Non-random allocation.
- Not energy-expenditure matched.
- Nonvalidated post-only subjective questionnaire.
- Physically active young adults only.

## Safety And Adherence

- No adverse events were reported in the reviewed article text.
- Participants with recent musculoskeletal injury or cardiovascular/metabolic contraindications were excluded; all sessions were supervised and heart-rate monitored.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/41900495/) (pubmed)
- [DOI](https://doi.org/10.3390/jfmk11010088) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13027164/) (full text)

## Agent Guidance

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