# Changes in Appetite-Dependent Hormones and Body Composition After 8 Weeks of High-Intensity Interval Training and Vitamin D Supplementation in Sedentary Overweight Men

PMID: 35198590
Journal: Frontiers in nutrition
Published: 2022
Authors: Sheikholeslami-Vatani D, Rostamzadeh N

## Question

Do 8 weeks of cycling HIIT and vitamin D3 supplementation, separately or together, change appetite hormones, appetite ratings, insulin, and body composition in sedentary overweight men?

## Summary

In 48 overweight sedentary college men with vitamin D deficiency, 8 weeks of supervised cycling HIIT reduced weight, BMI, body fat, insulin, hunger, and desire to eat, while increasing PYY, satiety, and fullness. Vitamin D supplementation raised vitamin D levels and may have added some appetite benefit, but the main body-composition and insulin improvements appeared in both HIIT groups.

## Population

- Sedentary overweight male college students with vitamin D deficiency
- Sample size: 48
- Age: 21.7 +/- 1.4 years
- Sex: Male
- Fitness level: Sedentary, lacking regular exercise in prior 6 months
- Health status: Overweight and vitamin D deficient

## Methodology

- Randomized controlled four-group intervention
- 8 weeks
- University exercise physiology laboratory with dormitory meal context
- Randomized and controlled study design.

## Protocol

- Cycling HIIT plus vitamin D/placebo.
- Modality: Cycling.
- Work intervals: 1 minute.
- Recovery: 1 minute active recovery at 15% VO2peak.
- Sets or repetitions: 10 intervals.
- Intensity: 90% VO2peak weeks 1-4; 100% VO2peak weeks 5-8.
- Session duration: About 50 minutes including warm-up/cool-down.
- Frequency: 3 sessions/week.
- Program length: 8 weeks.
- Progression: Intensity increased after week 4.
- Vitamin D only or control.
- Frequency: No regular training.
- Program length: 8 weeks.

## Outcomes

### PYY
Status: improved
PYY increased in both HIIT groups after 8 weeks.

Group x time F=36.5, p=0.001; HIIT groups p=0.001

### insulin
Status: improved
Insulin decreased in HIIT plus vitamin D, HIIT plus placebo, and vitamin D-only groups.

Group x time F=110.53, p=0.001

### body composition
Status: improved
Weight, BMI, and body fat percentage decreased in both HIIT groups compared with vitamin D-only and control groups.

Reported p=0.001 for HIIT-group changes and group comparisons

### appetite ratings
Status: improved
Hunger and desire to eat decreased while satiety and fullness increased in both HIIT groups.

Group x time interactions p=0.001

## Practical Insights

- One-minute cycling intervals with equal active recovery have evidence for appetite and body-composition shifts in overweight sedentary men.
- The long warm-up/main/cool-down structure may be more suitable for a training plan than a quick workout.
- Supplement status should be treated as context, not as part of workout generation.

## Limitations

- Men only
- Overweight college sample with vitamin D deficiency
- No clear adverse-event reporting
- Supplement co-intervention
- Lab-supervised cycling limits home translation

## Safety And Adherence

- The article did not report adverse events, injuries, symptoms, or a dropout/adherence rate.
- Participants completed health history, drug and dietary supplement use, and exercise-history questionnaires before eligibility; they were informed of risks and gave written consent.
- HIIT sessions were supervised by a research-team member and heart rate was controlled with a Polar RS400 monitor; pre/post tables retained n=12 per group but no attrition narrative was provided.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/35198590/) (pubmed)
- [DOI](https://doi.org/10.3389/fnut.2022.827630) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8860169/) (full text)

## Agent Guidance

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