Fasted vs. Fed State Exercise
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: 16 week exercise intervention.
- Who it may be relevant to
- Registry conditions: Obesity, Exercise, Weight Loss. Basic parameters: 18 years — 59 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- United States
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
Fasted vs. Fed State Exercise for Cardiovascular Health and Weight Loss
Overview
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.
Detailed description
This study will be the first to evaluate a long-term (16-week) aerobic exercise intervention performed in the fasted state (compared to fed state) at a guidelines-based dose. Primary outcomes for Aim 1 will include changes in fat \& fat-free mass (DXA), energy compensation, blood pressure \& lipids, aerobic fitness, and substrate oxidation (respiratory quotient, RQ) at rest and during activity.
It is also important to understand sources of response variability to an exercise program. Individuals tend to compensate for the energy they expend during exercise, primarily by increasing energy intake (EI). Such compensatory eating behaviors likely stem from a series of evolutionarily conserved responses, ensuring energy is available for vital organ function and reproduction when faced with an energy deficit. This proposal will be the first to evaluate how fasted exercise training influences (Aim 2 outcomes): physiological hunger (hormonal responses to a standardized meal) and behavioral constructs shown to influence EI and weight status (food reinforcement and attentional bias towards food cues). The overall hypothesis is that fasted state exercise will result in greater energy compensation, attenuating weight loss compared to an identical dose of exercise performed in the post-prandial state. This study will further hypothesize an attenuated weight loss with fasted exercise training will negate beneficial cardiovascular adaptations stemming from improvements in oxidative metabolism commonly associated with fasted exercise. Adults (aged 18-59 years, BMI: 25-45 kg/m2) will be randomized to a 16-week supervised aerobic exercise intervention (progressing to a guidelines-based dose of 1600 kcal/wk). Exercise sessions will be performed between 0500h and 1100h, 4 days per week in either the fasted state (FAST, 8-12 hour fast) or post-prandially (FED, within 3 hours of eating at least 300 kcal).
Interventions
- Behavioral 16 week exercise intervention
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).
Primary outcome measures
- body composition [Time frame: Baseline (week 0) and post-intervention (week 25)]
Secondary outcome measures (12)
- Total and acylated ghrelin [Time frame: Baseline (week 0) and post-intervention (week 25)]
- GLP-1 [Time frame: Baseline (week 0) and post-intervention (week 25)]
- PYY [Time frame: Baseline (week 0) and post-intervention (week 25)]
- Leptin [Time frame: Baseline (week 0) and post-intervention (week 25)]
- Food reinforcement [Time frame: Baseline (week 0) and post-intervention (week 25)]
- Attentional bias for food cues [Time frame: Baseline (week 0) and post-intervention (week 25)]
- Skeletal muscle efficiency [Time frame: Baseline (week 0) and post-intervention (week 25)]
- walking ecconomy [Time frame: Baseline (week 0) and post-intervention (week 25)]
- resting metabolic rate [Time frame: Baseline (week 0) and post-intervention (week 25)]
- muscle strength [Time frame: Baseline (week 0) and post-intervention (week 25)]
- muscle power [Time frame: Baseline (week 0) and post-intervention (week 25)]
- skeletal muscle mass [Time frame: Baseline (week 0) and post-intervention (week 25)]
Eligibility criteria
Inclusion criteria
- Aged 18-59
- BMI 25-45
- Healthy enough to exercise
Exclusion criteria
- 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)
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: Yes
Study design
- Allocation
- Randomized
- Model
- Parallel assignment
- Masking
- Open label
- Primary purpose
- Treatment
Study locations
United States · 1 center
- Arkansas Colleges of Health Education Research Institure Health and Wellness Center — Fort Smith
Identifiers
NCT: NCT07487090 · 479-401-6011