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OpenTrials
Completed

NCT Number: NCT05919979

Effect of a Physical Exercise Session Performed During a 24-34 Hour Fasting Period on Energy Metabolism and Cognitive Function in Healthy Adults

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.

Completed

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Key information

Conditions

Age range

18 year–40 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Instiuto Mixto Universitario Deporte y Salud

Granada, 18007, Spain

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • 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.

Exclusion criteria

  • 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.

Treatment and study plan

34-hour fasting in sedentary conditions

Behavioral

Participants will fast for 34h after a standardized breakfast, refraining from physical activity.

34-hour fasting with high-intensity exercise

Behavioral

Participants will fast for 34h after a standardized breakfast, performing a high-intensity exercise session 6-10 hours aprox. after starting the fasting period.

Primary outcomes

  1. Respiratory Exchange Ratio

    Time frame: 24-hour after starting the fasting period

Secondary outcomes

  1. Respiratory Exchange Ratio

    Time frame: 34-hour after starting the fasting period

  2. Serum insulin concentration

    Time frame: 24-hour after starting the fasting period

  3. Serum insulin concentration

    Time frame: 34-hour after starting the fasting period

  4. Serum glucose concentration

    Time frame: 24-hour after starting the fasting period

  5. Serum glucose concentration

    Time frame: 34-hour after starting the fasting period

  6. Dimensional Change Card Sort Test (NIH toolbox)

    Time frame: 24-hour after starting the fasting period

  7. Dimensional Change Card Sort Test (NIH toolbox)

    Time frame: 34-hour after starting the fasting period

  8. List Sorting Working Memory Test (NIH toolbox)

    Time frame: 24-hour after starting the fasting period

  9. List Sorting Working Memory Test (NIH toolbox)

    Time frame: 34-hour after starting the fasting period

  10. Flanker Test (NIH toolbox)

    Time frame: 24-hour after starting the fasting period

  11. Flanker Test (NIH toolbox)

    Time frame: 34-hour after starting the fasting period

Sponsors and collaborators

Lead sponsor

Universidad de Granada

Other

Collaborators

  • University Hospital Virgen de las Nieves

Registry information

Official study 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

Acronym: IMS

Important dates

Study start
2023
Primary completion
2025
Study completion
2025
First posted
Jun 27, 2023
Registry last updated
Dec 26, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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