Exercise, Chronotype, and Prediabetes

September 8, 2026 updated by: German Diabetes Center

Timed Exercise in Prediabetes With Extreme Chronotype

The goal of this clinical trial is to find out whether exercising at the right time of day, based on a person's natural body clock, leads to greater health benefits in people living with prediabetes. The main question it aims to answer is whether doing a single session of exercise in the morning or in the evening affects how the body handles sugar differently in adults with prediabetes who have an extreme natural body clock. This will be done by comparing three conditions (no-exercise, morning exercise, and evening exercise) within the same participant. Each condition will be tested on a different day, with at least 14 days between the test days. During the no-exercise test days, participants will come to the study centre and will only be allowed to do sedentary activities (e.g. office work, reading, or screen time). During the morning exercise test days, participants will perform an exercise session at 9:00 am that involves short periods of very hard effort followed by short rest periods. Whereas for the evening exercise test days, the same type of exercise will be performed at 5:00 pm.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Chronotype refers to an individual's circadian preferences for being active and fully functional at certain times of the day. Using validated questionnaires, individual's chronotype can be categorized to either a morning (lark), evening (owl), or intermediate (neutral) chronotypes. Individuals with morning chronotype wake up and go to bed early. Therefore, their calorie distribution as well as peak mental and physical performances predominantly occur earlier in the day. This is in contrast with individuals with evening chronotype that wake up and go to bed late, resulting in most of their calorie consumption happens later in the day. They are also more active and alert in the evening. Growing evidence has shown that late afternoon or evening exercise is better than morning exercise for blood glucose control in individuals with type 2 diabetes (T2D) or those at risk of T2D. In men with T2D, two weeks of high-intensity interval training (HIIT) reduced continuous glucose monitor (CGM)-based glucose concentration when performed in the afternoon than in the morning. This finding was further supported by a retrospective study involving men at risk for or T2D that found afternoon exercise led to superior peripheral insulin sensitivity, insulin-mediated suppression of adipose tissue lipolysis, and fasting plasma glucose. Interestingly, in a recently published crossover trial involving men and women, with and without T2D, no difference was observed in 24-hour glucose profile assessed using CGM across all cohorts (including gender and diabetes status) between morning and evening exercise. However, morning exercise increased post-exercise blood glucose levels during the two hours recovery period in both men and women with T2D, which was not observed following the evening exercise. It is important to note that all the above-mentioned studies are either excluding individuals with extreme chronotype or the chronotype of the participants was not clearly reported. This limitation raises an important research question: Do people living with extreme chronotype respond differently to timed exercise? Therefore, in this study, it is hypothesize that people living with prediabetes and extreme chronotype will gain superior metabolic benefits when the timing of exercise is aligned with their chronotype. To test this, a randomized controlled cross-over study is conducted in which participants are subjected to three conditions that are no-exercise, morning exercise, and evening exercise. The main outcome is insulin sensitivity determined by a 2-step hyperinsulinemic-euglycemic clamp.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
28

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • Germany
      • Düsseldorf, Germany, 40225
        • Recruiting
        • German Diabetes Center (DDZ)
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Able to provide signed and dated written informed consent prior to any study specific procedures
  2. Adult men and women aged between more than 18 and ≤ 75 years
  3. Body mass index (BMI) of 25 - 35 kg/m2
  4. Stable weight (no weight loss or gain > 3 kg in the past 3 months)

  5. Pre-diabetes defined as an isolated impaired glucose tolerance or a combination of impaired glucose tolerance and impaired fasting glucose (values are based on the American Diabetes Association (ADA):

    1. impaired glucose tolerance (plasma glucose 140 mg/dL to 199 mg/dL, 120 minutes after consumption of 75g of glucose)
    2. impaired fasting glucose (fasting plasma glucose 100 mg/dL to 125 mg/dL)
  6. Morning (Morningness-Eveningness Questionnaire [MEQ] score ≥ 59) or evening (MEQ score ≤ 41) chronotype

Exclusion Criteria:

  1. Previously diagnosed with type 2 diabetes
  2. Moderate to severe anemia (hemoglobin < 10 g/L)
  3. Uncontrolled hypertension
  4. Abnormal electrocardiogram (ECG) at rest judged by the study physician
  5. Pregnancy or breastfeeding
  6. HIV, hepatitis B, or C infection
  7. Disorders of blood clotting or wound healing
  8. Positive history of venous thrombosis (contraindication for clamp)
  9. Hypersensitivity to local anesthetics (contraindication for fat/muscle biopsies)
  10. Night shift work in the last 3 months
  11. Travel across > 1 time zone in the last 3 months
  12. Participation in another clinical trials that may possibly hamper the study results
  13. Engagement in structured exercise activities > 2 hours a week
  14. Any acute condition, exacerbation of chronic condition, or medical history that in the investigator's opinion would interfere with the study
  15. Any contraindication for MRI scanning
  16. Medication use known to hamper safety during the study procedures
  17. Non-German speaking

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: AM exercise
Behavioral: Timing of exercise
Behavioral: Timing of exercise
An acute exercise bout of cycling performed in the morning at 9 AM
Behavioral: Timing of exercise
An acute exercise bout of cycling performed in the morning at at 5 PM
Experimental: PM exercise
Behavioral: Timing of exercise
Behavioral: Timing of exercise
An acute exercise bout of cycling performed in the morning at 9 AM
Behavioral: Timing of exercise
An acute exercise bout of cycling performed in the morning at at 5 PM
Active Comparator: Control
Behavioral: Control
Behavioral: Control
No exercise

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Insulin sensitivity
Time Frame: 12 to 24 hours post-exercise intervention
Effect of timed exercise on insulin sensitivity assessed using insulin sensitivity index (reported as M-value: mg x kg-1 x min-1) during an hyperinsulinemic-euglycemic clamp
12 to 24 hours post-exercise intervention

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Skeletal muscle metabolites
Time Frame: 12 to 24 hours post-exercise intervention
Effect of timed exercise on skeletal muscle mitochondrial respiration (pmol/mg/s) measured with high resolution respirometry
12 to 24 hours post-exercise intervention
Skeletal muscle clock genes
Time Frame: 12 to 24 hours post-exercise intervention
Effect of timed exercise on quantified DNA measured with quantitative polymerase chain reaction (qPCR)
12 to 24 hours post-exercise intervention
Adipose tissue metabolites
Time Frame: 12 to 24 hours post-exercise intervention
Effect of timed exercise on adipose tissue mitochondrial respiration (pmol/mg/s) measured with high resolution respirometry
12 to 24 hours post-exercise intervention
Adipose tissue clock genes
Time Frame: 12 to 24 hours post-exercise intervention
Effect of timed exercise on quantified DNA measured with quantitative polymerase chain reaction (qPCR)
12 to 24 hours post-exercise intervention
Hepatic glycogen content assessed using 13C Magnetic Resonance Spectroscopy
Time Frame: Post-dinner on exercise day
Effect of timed exercise on hepatic glycogen content, expressed in millimoles per liter (mmol/L) of liver tissue
Post-dinner on exercise day
Serum glucose
Time Frame: 12 to 24 hours post-exercise intervention
Effect of timed exercise on serum glucose levels (mg/dL) determined from venous blood draws
12 to 24 hours post-exercise intervention
Serum free fatty acids
Time Frame: 12 to 24 hours post-exercise intervention
Effect of timed exercise on serum free fatty acid levels (mmol/L) determined from venous blood draws
12 to 24 hours post-exercise intervention
Serum triglycerides
Time Frame: 12 to 24 hours post-exercise intervention
Effect of timed exercise on serum triglycerides (mg/dL) determined from venous blood draws
12 to 24 hours post-exercise intervention
Serum cholesterol
Time Frame: 12 to 24 hours post-exercise intervention
Effect of timed exercise on serum cholesterol (mg/dL) determined from venous blood draws
12 to 24 hours post-exercise intervention
Serum insulin
Time Frame: 12 to 24 hours post-exercise intervention
Effect of timed exercise on serum insulin levels (uIU/mL) determined from venous blood draws
12 to 24 hours post-exercise intervention
Resting energy expenditure assessed using indirect calorimetry
Time Frame: 12 to 24 hours post-exercise intervention
Effect of timed exercise on resting energy expenditure, expressed in kilocalories per day (kcal/day)
12 to 24 hours post-exercise intervention
Objective sleep quantity and quality assessed using an actighrapy device
Time Frame: The nighttime of exercise intervention day
Effect of timed exercise on sleep duration, efficiency, and fragmentation are measured objectively from the actighrapy device
The nighttime of exercise intervention day

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Liver lipid content measured using ¹H/³¹P Magnetic Resonance Spectroscopy
Time Frame: Baseline assessment
To assess the difference in liver lipid content in percentage (%) between morning versus evening chronotypes
Baseline assessment
Skeletal muscle lipid content measured using ¹H/³¹P Magnetic Resonance Spectroscopy
Time Frame: Baseline assessment
To assess the difference in skeletal muscle lipid content in percentage (%) between morning versus evening chronotypes
Baseline assessment
Body composition expressed as fat mass (kg and %) and fat-free mass (kg) assessed using Bodpod and Bioelectrical Impedance
Time Frame: Baseline assessment
To assess the difference in body composition between morning versus evening chronotypes
Baseline assessment
Maximal aerobic capacity measured using spiroergometry
Time Frame: Baseline assessment
To assess the difference in maximal aerobic capacity (VO₂max) between morning versus evening chronotypes
Baseline assessment
Subjective sleep quality assessed using the Pittsburgh Sleep Quality Index (PSQI)
Time Frame: Baseline assessment
To assess the difference in subjective sleep quality between morning versus evening chronotypes. Total score range of 1 to 21, higher scores indicating poorer sleep quality
Baseline assessment
Level of sleepiness assessed using the Stanford Sleepiness Scale (SSS)
Time Frame: Baseline assessment
To assess the difference in level of sleepiness between morning versus evening chronotypes. On a 7-point scale, 1 representing feeling alert and 7 indicating being almost in reverie
Baseline assessment
Consumption of specific foods or food groups assessed using the DEGS1-Food Frequency Questionnaire (FFQ)
Time Frame: Baseline assessment
To assess the difference in consumption frequency of specific foods or food groups (expressed as times per week) between morning versus evening chronotypes
Baseline assessment
Hedonic hunger assessed using the Power of Food Scale questionnaire
Time Frame: Baseline assessment
To assess the difference in hedonic hunger between morning versus evening. Mean score of 15 items rated on a 5-point Likert scale (range 1-5). Higher scores indicate greater psychological responsiveness to food cues
Baseline assessment
Severity and type of food cravings assessed using the Control of Eating Questionnaire (CoEQ)
Time Frame: Baseline assessment
To assess the difference in self-reported craving strength between morning versus evening chronotypes. A numeric rating scale ranges from 0 to 10. Higher scores indicate stronger food cravings
Baseline assessment
Subjective physical activity levels determined using the International Physical Activity Questionnaire (IPAQ)
Time Frame: Baseline assessment
To assess subjective physical activity levels (low, moderate, high expressed as MET-minutes/week) between morning versus evening chronotypes
Baseline assessment
Cognitive performance assessed using the Sustained Attention to Response Test (SART)
Time Frame: Baseline assessment
To assess the difference in cognitive performance between morning versus evening chronotypes. Performance is assessed using commission errors (incorrect responses to no-go stimuli), omission errors (missed responses to go stimuli), mean reaction time, and reaction time variability, with higher error rates and greater reaction time variability indicating poorer sustained attention and inhibitory control
Baseline assessment
Cognitive performance assessed using the Brief Psychomotor Vigilance Test (PVT-B)
Time Frame: Baseline assessment
To assess the difference in cognitive performance between morning versus evening chronotypes. Performance is assessed using mean reaction time, number of lapses (reaction times ≥500 ms), and fastest 10% reaction times, with slower reaction times and more lapses indicating reduced vigilant attention and alertness.
Baseline assessment
Well-being assessed using the World Health Organization-Five Well-being Index (WHO-5)
Time Frame: Baseline assessment
To assess the difference in well-being between morning versus evening chronotypes. Scores range from 0 to 25 with higher scores indicating better well-being and psychological health
Baseline assessment
Mental health assessed using the Patient Health Questionnaire-9 (PHQ-9)
Time Frame: Baseline assessment
To assess the difference in mental health between morning versus evening chronotypes. A 9-item self-report questionnaire assessing depressive symptoms over the past two weeks, scored from 0 to 27 with higher scores indicating greater severity of depressive symptoms
Baseline assessment
Quality of life assessed using the 36-Item Short Form Survey Instrument (SF-36)
Time Frame: Baseline assessment
To assess the difference in quality of life between morning versus evening chronotypes. A self-report questionnaire assessing health-related quality of life across eight domains-physical functioning, role limitations due to physical health, bodily pain, general health, vitality, social functioning, role limitations due to emotional problems, and mental health-with scores transformed to a 0-100 scale, where higher scores indicate better health and functioning
Baseline assessment

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
German Diabetes Center

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Patrick Schrauwen, PhD, German Diabetes Center

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
August 1, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
August 1, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
January 20, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 28, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
February 5, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 11, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 8, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • REALIGN

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Participant data will only be discussed with other researcher on group level. We are not interested in sharing individual participant data.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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