Fasted vs. Fed State Exercise

NCT07487090 | Recruiting Phase 2

• 1 other identifier: 479-401-6011
• Study Type: interventional
• Target: 40
• Locations: 1 country
• Sites: 1

Brief Summary

Although many medications exist for both heart disease and obesity, cost, lack of access for all people, side effects and the desire for a more natural solution have left many people seeking lifestyle treatments such as exercise. Scientists know that exercise is highly beneficial for heart health. When exercise also produces weight loss, these benefits are much improved. Although using exercise to treat or prevent heart disease / obesity is recommended, not all people respond well. Some see significant weight loss and health improvements while others see little changes. For these reasons, new strategies surrounding the use and design of an exercise program are needed. One such strategy could be performing aerobic exercise before breakfast (fasted exercise). When exercising fasted, food/energy stores are low, and one relies on stored body fat for energy. This may help heart health and weight loss. This has never been tested in a program long enough to see such changes. This study will, for the first time, assess the effects of a 16-week aerobic exercise program performed fasted compared to after eating. Outcomes will include blood fats, blood pressure, fat-burning abilities and weight loss. Starting an exercise program can also make people to eat more. This limits the success of exercise. The study will also evaluate ways fasted exercise could change eating, as it possible that fasted exercise could also cause people to eat more, which would limit weight loss and health improvements.

Conditions

Obesity; Exercise; Weight Loss

Keywords

Exercise; weight loss; obesity

Outcome Measures

Primary Outcomes (1)

• body composition

  kg of fat free and fat mass via DXA

  Baseline (week 0) and post-intervention (week 25)

Secondary Outcomes (12)

• Total and acylated ghrelin

  Baseline (week 0) and post-intervention (week 25)

• GLP-1

  Baseline (week 0) and post-intervention (week 25)

• PYY

  Baseline (week 0) and post-intervention (week 25)

• Leptin

  Baseline (week 0) and post-intervention (week 25)

• Food reinforcement

  Baseline (week 0) and post-intervention (week 25)

Study Arms (2)

Fasted group

EXPERIMENTAL

Complete all exercise sessions of intervention before breakfast- fasted at least 8 hours

Behavioral: 16 week exercise intervention

Fed exercise group

EXPERIMENTAL

Complete all exercise sessions of intervention after breakfast- within 3 hours of eating at least 300 kcal

Behavioral: 16 week exercise intervention

Interventions

16 week exercise intervention BEHAVIORAL

Both groups will receive a 16-week supervised aerobic exercise program progressing to 1,600 kcal of EE per wk (4 sessions/week) at moderate intensity (40-50% heart rate reserve, HRR).

Fasted group; Fed exercise group

Eligibility Criteria

• Age: 18 Years - 59 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Aged 18-59
• BMI 25-45
• Healthy enough to exercise

You may not qualify if:

• Taking medications or supplements that are known to influence energy expenditure,
• Currently exercising more than once per week
• Currently dieting for weight loss
• Currently taking weight loss drugs
• Have had a previous weight loss surgery
• Currently diagnosed with Diabetes
• Currently diagnosed with heart disease (Heart failure, uncontrolled hypertension, uncontrolled hypercholesterolemia, Coronary heart disease)

Sponsors & Collaborators

• Arkansas Colleges of Health Education: lead

Study Sites (1)

Arkansas Colleges of Health Education Research Institure Health and Wellness Center

Fort Smith, Arkansas, 72916, United States

RECRUITING

MeSH Terms

Conditions

Obesity; Motor Activity; Weight Loss

Condition Hierarchy (Ancestors)

Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Behavior; Body Weight Changes

Central Study Contacts

Kyle D Flack, PhD

CONTACT

(479) 434-4019; kyle.flack@achehealth.edu

Blake Metcalf, DCN

CONTACT

479-434-4003; blake.metcalf@achehealth.edu

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: NONE
• Masking Details: Cannot blind groups
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Director of the Center for Translational Research, Associate Professor of Pathology, Pharmacology & Physiology

Model Details: 2 group trial, 1:1 allocation, Fed exercise group (complete all exercise sessions of the intervention within 3 hrs of eating) vs. Fasted exercise group (complete all exercise sessions of the intervention in fasted state)

Study Record Dates

• First Submitted: March 13, 2026
• First Posted: March 23, 2026
• Study Start: January 5, 2026
• Primary Completion (Estimated): July 1, 2027
• Study Completion (Estimated): December 1, 2027
• Last Updated: March 23, 2026

Record last verified: 2026-03

Locations

US (1)