How exercise timing affects after-meal blood sugar

Exercise Timing and Postprandial Glucose Responses in Healthy Adults

Not applicable Interventional Technical University of Munich · NCT07434349

This study tests whether running before or after breakfast or dinner changes after-meal blood sugar in healthy, active young adults.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment30 (estimated)
Ages18 Years to 35 Years
SexAll
SponsorTechnical University of Munich Academic / other
Locations1 site (München, Bavaria)
Trial IDNCT07434349 on ClinicalTrials.gov

What this trial studies

This randomized repeated-measures crossover trial has each participant complete five conditions over a 14-day period while wearing a continuous glucose monitor. Conditions include a 45-minute vigorous outdoor run performed before or after breakfast or dinner, plus a no-exercise control, with exercise set at 75–85% of maximal heart rate. All meals are fully standardized, high–glycemic-load, and served at fixed times (08:00, 13:00, 18:00), and postprandial glucose is measured for the three consecutive meals following each condition. The order of conditions is randomized and every participant completes all five conditions to allow within-person comparisons.

Who should consider this trial

Good fit: Ideal candidates are healthy, endurance-trained adults aged 18–35 with BMI 18.5–24.9 who can run continuously for 45 minutes at 75–85% of maximal heart rate and have habitual wake times compatible with an 08:00 breakfast.

Not a fit: People with metabolic disorders, those taking medications that affect glucose, individuals with BMI ≥25, pregnant or breastfeeding people, or those unable to complete vigorous running are unlikely to benefit from this protocol.

Why it matters

Potential benefit: If successful, the findings could help people time endurance exercise to lower after-meal blood sugar and improve day-to-day glucose control.

How similar studies have performed: Previous studies have found that exercise timing can alter postprandial glucose in both people with diabetes and healthy adults, but results have been mixed and this tightly controlled crossover with continuous glucose monitoring is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Age 18 to 35 years
* Body mass index 18.5 to 24.9 kg per square meter
* Able to complete 45 minutes of continuous running at an intensity corresponding to 75 to 85 percent of maximal heart rate without stopping
* Engages in regular endurance-type physical activity
* Habitual waking times are compatible with the fixed breakfast time of 08:00
* Willing and able to comply with all study procedures, including standardized meals, exercise sessions, behavioral restrictions, and continuous glucose monitoring
* For female participants: non-pregnant and using stable hormonal contraception for at least 3 months

Exclusion Criteria:

* Acute or chronic illness
* Metabolic disorders or conditions associated with altered glucose or lipid metabolism
* Use of medications known to interfere with glucose metabolism or study outcomes
* Intolerance or allergy to components of the standardized study diets
* Pregnancy or breastfeeding
* Body mass index greater than or equal to 25 kg per square meter
* Current or past eating disorder, or any medical condition or medication that could affect appetite regulation, glucose regulation, or make vigorous endurance exercise unsafe
* Current smoking or use of nicotine-containing products

Where this trial is running

München, Bavaria

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Exercise TimingPostprandial GlucoseContinuous Glucose MonitoringEndurance ExerciseGlycemic Response
Last reviewed 2026-06-09 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.