An interventional study of Timing of exercise in Pre-diabetes and Overweight and Obesity, sponsored by Maastricht University Medical Center. Completed at 1 site in Netherlands. Open to participants aged 40 Years to 75 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-04-17.
Sponsored by Maastricht University Medical Center · Not applicable, Interventional, and Prevention
n a retrospective analysis of an exercise training program performed either in the morning or afternoon, we found that the afternoon training group improved their peripheral insulin sensitivity and fasting plasma glucose levels to a greater extent than the morning group. However, underlying mechanisms are unclear.
The primary study endpoint is nocturnal glucose levels measured by a continuous glucose monitor (CGM).
Rationale: Various metabolic processes, including resting metabolic rate, insulin sensitivity and insulin secretion, follow a recurring 24-hour cycle. These rhythms are shown to be disturbed in in pre-diabetes volunteers compared to young healthy volunteers. In a retrospective analysis of an exercise training program performed either in the morning or afternoon, we found that the afternoon training group improved their peripheral insulin sensitivity and fasting plasma glucose levels to a greater extent than the morning group. However, underlying mechanisms are unclear.
Objective: The main objective of this study is to determine whether prolonged exercise training in the afternoon (15:00-17:00 PM) differs from exercise training in the morning (07:00-09:00 AM) in improving insulin sensitivity in individuals with pre-diabetes, and to investigate its underlying mechanisms.
Study design: The present study is a randomized double arm longitudinal intervention study in a pre and post design.
Study population: 24 pre-diabetic individuals (men and postmenopausal women aged 40 - 75 years and with BMI ≥ 25 and ≤ 38 kg/m2) will complete this study (12 participants in the morning training group and 12 participants in the afternoon training group). From experience with similar studies, we estimate a drop-out rate of 20% and a screening failure of 70% (because individuals often do not know they are pre-diabetic). This results in maximally 30 participants that have to be included and 100 participants that have to be screened (maximally).
Intervention (if applicable): Participants will perform a 12-weeks supervised high intensity interval training (HIIT) program with three \~30 min exercise sessions per week. Participants will be randomly assigned to the morning or afternoon training time. To assess the outcomes, participants will come to the university for a 43h measurement period both before and after the 12-week training program.
Main study parameters/endpoints: The primary study endpoint is nocturnal glucose levels measured by a continuous glucose monitor (CGM). The secondary outcomes are 24h energy and substrate metabolism. Exploratory outcomes are body composition, intrahepatic lipid content and composition, hepatic insulin sensitivity, hepatic glycogen levels, maximal aerobic capacity, skeletal muscle oxidative capacity, visceral and subcutaneous adipose tissue volume, sleeping metabolic rate, blood glucose levels (continuously measured over 7days) and immune responses.
778 studies on the registry are indexed under Glucose Intolerance; 129 are open to participants now.
This study's enrollment of 15 is below the median of 60 across 645 interventional studies indexed under Glucose Intolerance.
Browse Glucose Intolerance studies →Maastricht University Medical Center is the lead sponsor of 835 studies on the registry; 122 are open to participants now.
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Pre-diabetes based on one or a combination of the following criteria:
Exclusion Criteria:
HIIT program performed between 07:00-09:00 AM
Behavioral: Timing of exercise
HIIT program performed between 15:00-17:00 PM
Behavioral: Timing of exercise
High Intensity Interval Training (HIIT) program for 12 weeks (3 per week/36 sessions in total)
nocturnal glucose levels
The main objective of this study is to determine whether prolonged exercise training in the afternoon differs from exercise training in the morning in improving nocturnal glucose levels insulin sensitivity in individuals with pre-diabetes.
Time frame: measured before and after the 12 weeks training program
24h whole body energy expenditure
energy expenditure as measured by a 24h stay in the respiration chamber
Time frame: measured before and after the 12 weeks training program
24h substrate metabolism
24h substrate metabolism as measured by a 24h stay in the respiration chamber
Time frame: measured before and after the 12 weeks training program
Body composition by Dual Energy X-ray Absorptiometry (DEXA)
fat-free mass (kg and percentage)
Time frame: measured before and after the 12 weeks training program
Body composition by Dual Energy X-ray Absorptiometry (DEXA)
fat mass (kg and percentage)
Time frame: measured before and after the 12 weeks training program
Intrahepatic lipid content and composition
Time frame: measured before and after the 12 weeks training program
Hepatic glycogen levels
Time frame: measured before and after the 12 weeks training program
VO2 max cycling test
measurement of participants' maximal aerobic capacity, absolute (L/min) and relative (ml/min/kg)
Time frame: measured before and after the 12 weeks training program
Skeletal muscle oxidative capacity
Ex vivo high-resolution respirometry using a two chamber Oxygraph (OROBOROS Instruments) will be performed. Multiple substrate/inhibitor titration protocols will be applied to extensively characterize the mitochondrial capacity of skeletal muscle fibers
Time frame: measured before and after the 12 weeks training program
Sleeping metabolic rate
Time frame: measured before and after the 12 weeks training program
Blood glucose levels measured continuously over 7 days.
Time frame: measured before and at the end the 12 weeks training program
This study is completed, as verified in Apr 2026. You cannot join it, but the record below documents what was studied.
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Maastricht University Medical Center