Energy MetabolismIMSNCT05919979
Effect of a Physical Exercise Session Performed During a 24-34 Hour Fasting Period on Energy Metabolism and Cognitive Function in Healthy Adults
A study testing 34-hour fasting in sedentary conditions and 34-hour fasting with high-intensity exercise in people with Energy Metabolism, run by Universidad de Granada at 1 site in Spain.
Trial summary
This study explores the impact of high-intensity exercise during fasting on energy metabolism and cognitive function in healthy adults. Changes in respiratory exchange ratio, blood substances, and cognitive performance will be measured after 24 and 34 hours of fasting with and without exercise in a randomized… Read more about this study
- Who is it for?
- Ages 18 to 40 yearsHealthy volunteers can take part
- Conditions the study is for
- Energy Metabolism
- What is being tested?
- 34-hour fasting in sedentary conditions and 34-hour fasting with high-intensity exercise
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 25 participants
- Where
- 1 siteSpain
- Study dates
- 29 May 2023to 18 Jun 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 40 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- 18-40 years old.
- Body mass index: 18.5-30.0 Kg/m2.
- Stable body weight (5kg range within the last 3 months)
- Being able to consume all the food items provided as part of the study.
- Not having change the time zone or have shifted sleeping hours equivalent to more than 3 hours on the previous 2 weeks.
Who cannot join
- Diagnosed with any chronic condition that, in the research team's opinion or based on the American College of Sports Medicine guidelines, could contraindicate the implementation of 34-hour fasting periods and/or high-intensity exercise.
- Diagnosed with a chronic endocrine, digestive, rheumatic, neurological, cardiac, pulmonary, autoimmune, or infectious condition that affects energy metabolism.
- Presenting any signs or symptoms of illness that, in the research team's opinion or based on the American College of Sports Medicine guidelines, could contraindicate the implementation of 34-hour fasting periods and/or high-intensity exercise.
- Pregnant or breastfeeding.
- Using medications or supplements that may alter energy metabolism.
- Currently undergoing or having undergone any type of nutritional intervention or treatment in the past 3 months.
- Engaging in more than 5 hours per week of habitual moderate-to-vigorous cycling.
- Any other condition that, in the research team's opinion, discourages participation in the study.
Trial locations and contacts
1 site in 1 country.
Spain1 site
Instiuto Mixto Universitario Deporte y Salud
Granada, Granada, 18007
About this study
Official title: Efecto de Una sesión de Ejercicio físico Realizada Durante un Periodo de Ayuno de 24-34 Horas Sobre el Metabolismo energético y la función Cognitiva en Adultos Sanos: Estudio Piloto
This study explores the impact of high-intensity exercise during fasting on energy metabolism and cognitive function in healthy adults. Changes in respiratory exchange ratio, blood substances, and cognitive performance will be measured after 24 and 34 hours of fasting with and without exercise in a randomized crossover design.
- Conditions
- Energy Metabolism
- Being tested
- 34-hour fasting in sedentary conditions, 34-hour fasting with high-intensity exercise
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
34-hour fasting in sedentary conditionsBehavioural
Participants will fast for 34h after a standardized breakfast, refraining from physical activity.
34-hour fasting with high-intensity exerciseBehavioural
Participants will fast for 34h after a standardized breakfast, performing a high-intensity exercise session 6-10 hours aprox. after starting the fasting period.
| Study group | Role | What they receive |
|---|---|---|
| Fasting, then fasting+exercise | Experimental | Not described Receives: Behavioral: 34-hour fasting in sedentary conditions; Behavioral: 34-hour fasting with high-intensity exercise |
| Fasting + Exercise, then fasting | Experimental | Not described Receives: Behavioral: 34-hour fasting in sedentary conditions; Behavioral: 34-hour fasting with high-intensity exercise |
What is being measured
The primary outcome is the main question the study is designed to answer.
Respiratory Exchange Ratio
Measured: 24-hour after starting the fasting period
Secondary outcomes (11)
Respiratory Exchange Ratio
Measured: 34-hour after starting the fasting period
Serum insulin concentration
Measured: 24-hour after starting the fasting period
Serum insulin concentration
Measured: 34-hour after starting the fasting period
Serum glucose concentration
Measured: 24-hour after starting the fasting period
Serum glucose concentration
Measured: 34-hour after starting the fasting period
Dimensional Change Card Sort Test (NIH toolbox)
Measured: 24-hour after starting the fasting period
Dimensional Change Card Sort Test (NIH toolbox)
Measured: 34-hour after starting the fasting period
List Sorting Working Memory Test (NIH toolbox)
Measured: 24-hour after starting the fasting period
List Sorting Working Memory Test (NIH toolbox)
Measured: 34-hour after starting the fasting period
Flanker Test (NIH toolbox)
Measured: 24-hour after starting the fasting period
Flanker Test (NIH toolbox)
Measured: 34-hour after starting the fasting period
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Jun 2023
- Study start29 May 2023
- Primary completion11 Jun 2025
- Study completion18 Jun 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Energy MetabolismStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Enrolment
- 25 participants (actual)
Sponsor and investigators
- Lead sponsor
- Universidad de Granada
- Sponsor type
- University, hospital or other
- Collaborators
- University Hospital Virgen de las Nieves
- Responsible party
- Principal investigator, Guillermo Sanchez Delgado, Universidad de Granada
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05919979
- Sponsor's protocol ID
- GSD-2023-002
- Acronym
- IMS
- Status last verified
- Dec 2025
- First submitted
- 5 Jun 2023
- Last updated
- 26 Dec 2025
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 26 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Efecto de Una sesión de Ejercicio físico Realizada Durante un Periodo de Ayuno de 24-34 Horas Sobre el Metabolismo energético y la función Cognitiva en Adultos Sanos: Estudio Piloto
- ClinicalTrials.gov ID
- NCT05919979
- Acronym / sponsor ID
- IMS / GSD-2023-002
- Conditions
- Energy Metabolism
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 25 participants (actual)
- Lead sponsor
- Universidad de GranadaUniversity, hospital or other
- Collaborators
- University Hospital Virgen de las Nieves
- Study start
- 29 May 2023 (actual)
- Primary completion
- 11 Jun 2025 (actual)
- Study completion
- 18 Jun 2025 (actual)
- First posted
- 27 Jun 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study explores the impact of high-intensity exercise during fasting on energy metabolism and cognitive function in healthy adults. Changes in respiratory exchange ratio, blood substances, and cognitive performance will be measured after 24 and 34 hours of fasting with and without exercise in a randomized crossover design.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Fasting, then fasting+exercise | Experimental | Behavioral: 34-hour fasting in sedentary conditions, Behavioral: 34-hour fasting with high-intensity exercise |
| Fasting + Exercise, then fasting | Experimental | Behavioral: 34-hour fasting in sedentary conditions, Behavioral: 34-hour fasting with high-intensity exercise |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- 18-40 years old.
- Body mass index: 18.5-30.0 Kg/m2.
- Stable body weight (5kg range within the last 3 months)
- Being able to consume all the food items provided as part of the study.
- Not having change the time zone or have shifted sleeping hours equivalent to more than 3 hours on the previous 2 weeks.
Key exclusion criteria (8 listed)
- Diagnosed with any chronic condition that, in the research team's opinion or based on the American College of Sports Medicine guidelines, could contraindicate the implementation of 34-hour fasting periods and/or high-intensity exercise.
- Diagnosed with a chronic endocrine, digestive, rheumatic, neurological, cardiac, pulmonary, autoimmune, or infectious condition that affects energy metabolism.
- Presenting any signs or symptoms of illness that, in the research team's opinion or based on the American College of Sports Medicine guidelines, could contraindicate the implementation of 34-hour fasting periods and/or high-intensity exercise.
- Pregnant or breastfeeding.
- Using medications or supplements that may alter energy metabolism.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| 34-hour fasting in sedentary conditionsParticipants will fast for 34h after a standardized breakfast, refraining from physical activity. | Behavioural | Fasting + Exercise, then fasting, Fasting, then fasting+exercise |
| 34-hour fasting with high-intensity exerciseParticipants will fast for 34h after a standardized breakfast, performing a high-intensity exercise session 6-10 hours aprox. after starting the fasting period. | Behavioural | Fasting + Exercise, then fasting, Fasting, then fasting+exercise |
Primary outcome
Respiratory Exchange Ratio
Time frame: 24-hour after starting the fasting period
11 secondary outcomes
Respiratory Exchange Ratio
Time frame: 34-hour after starting the fasting period
Serum insulin concentration
Time frame: 24-hour after starting the fasting period
Serum insulin concentration
Time frame: 34-hour after starting the fasting period
Serum glucose concentration
Time frame: 24-hour after starting the fasting period
Serum glucose concentration
Time frame: 34-hour after starting the fasting period
Dimensional Change Card Sort Test (NIH toolbox)
Time frame: 24-hour after starting the fasting period
Dimensional Change Card Sort Test (NIH toolbox)
Time frame: 34-hour after starting the fasting period
List Sorting Working Memory Test (NIH toolbox)
Time frame: 24-hour after starting the fasting period
List Sorting Working Memory Test (NIH toolbox)
Time frame: 34-hour after starting the fasting period
Flanker Test (NIH toolbox)
Time frame: 24-hour after starting the fasting period
Flanker Test (NIH toolbox)
Time frame: 34-hour after starting the fasting period
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 26 Dec 2025.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing 34-hour fasting in sedentary conditions and 34-hour fasting with high-intensity exercise in people with Energy Metabolism, run by Universidad de Granada at 1 site in Spain.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 26 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Spain. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Respiratory Exchange Ratio (time frame: 24-hour after starting the fasting period). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 26 Dec 2025.