High-intensity interval exercise to improve vitamin D levels in adults with overweight or obesity

The Impact of Hybrid-type High-intensity Interval Training on Vitamin D Metabolism in Adults With Overweight/Obesity

Not applicable Interventional University of Thessaly · NCT07300332

This trial will try three hybrid high-intensity interval sessions per week for 12 weeks to see if exercise increases vitamin D (25(OH)D) in adults with overweight or obesity during winter.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment30 (estimated)
Ages35 Years to 50 Years
SexAll
SponsorUniversity of Thessaly Academic / other
Locations1 site (Trikala, Karyes)
Trial IDNCT07300332 on ClinicalTrials.gov

What this trial studies

Thirty adults with BMI 25–35 kg/m2 will be randomly assigned to an Exercise group or a Control group. The Exercise group will perform three supervised hybrid high-intensity interval training sessions per week for 12 weeks while following a balanced diet; the Control group will follow the same balanced diet but not perform the exercise program. Both groups will have resting blood draws for 25-hydroxyvitamin D, body composition measured by bioelectrical impedance, 24-hour dietary recalls, and physical activity monitored by accelerometry at baseline, 6 weeks, and 12 weeks. The study is conducted over winter at the University of Thessaly and excludes participants using vitamin D supplements or certain medications.

Who should consider this trial

Good fit: Adults with BMI 25–35 kg/m2 who are non-smokers, free of musculoskeletal injuries and chronic health complications, and not taking vitamin D supplements, statins, steroids, or chronic anti-inflammatory drugs are ideal candidates.

Not a fit: People taking vitamin D supplements, smokers, those with BMI outside 25–35 kg/m2, with chronic health conditions, or who cannot safely perform high-intensity exercise are unlikely to benefit from this protocol.

Why it matters

Potential benefit: If successful, this could offer a non-drug way to boost circulating vitamin D in adults with overweight or obesity, especially during months with low sun exposure.

How similar studies have performed: Previous studies showed that moderate-intensity cardiovascular exercise can blunt winter declines in 25(OH)D in adults with overweight/obesity, but the use of hybrid high-intensity interval training for this purpose is less well studied.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* BMI = 25-35 kg/m2
* Absence of musculoskeletal injuries
* Absence of chronic health-related complications
* Non-smokers

Exclusion Criteria:

* Consumption of Vitamin D supplements
* Consumption of anti-inflammatory drugs, statins and/or steroids

Where this trial is running

Trikala, Karyes

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Obesity & OverweightVitamin Doverweightobesityvitamin D25-hydroxyvitamin Dhigh-intensity interval training
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.