Exercise Timing and Postprandial Glucose Responses

NCT07434349 | Recruiting

• 1 other identifier: ExTime-Glu
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

This interventional crossover study examines the effect of exercise timing relative to meal intake on postprandial glucose responses in healthy, physically active young adults. Participants complete five experimental conditions involving endurance exercise performed before or after breakfast or dinner, as well as a non-exercise control condition, while wearing a continuous glucose monitoring device. Postprandial glucose responses are assessed for the three consecutive meals following each exercise session. Following morning exercise, outcomes are assessed after breakfast, lunch, and dinner on the same day. Following evening exercise, outcomes are assessed after dinner on the same day and after breakfast and lunch on the subsequent day. All meals are standardized and consumed at fixed clock times.

Conditions

Exercise Timing; Postprandial Glucose

Keywords

Exercise Timing; Postprandial Glucose; Continuous Glucose Monitoring; Endurance Exercise; Glycemic Response

Outcome Measures

Primary Outcomes (1)

• 3-hour postprandial glucose area under the curve (AUC)

  The area under the curve for interstitial glucose concentration during the 3-hour period following each of the three consecutive meals assessed after each exercise or control condition, measured using continuous glucose monitoring.

  During each intervention condition within the 14-day study period, assessed over the 3-hour period following each of the three consecutive meals after each condition

Secondary Outcomes (5)

• Incremental postprandial glucose AUC

  During each intervention condition within the 14-day study period, assessed over the 3-hour period following each of the three consecutive meals after each condition

• Peak postprandial glucose concentration

  During each intervention condition within the 14-day study period, assessed over the 3-hour period following each of the three consecutive meals after each condition

• Time to peak glucose

  During each intervention condition within the 14-day study period, assessed over the 3-hour period following each of the three consecutive meals after each condition

• Subjective appetite ratings

  Repeatedly during each intervention condition within the 14-day study period, assessed before and after each meal and exercise session

• Rating of perceived exertion

  Immediately after each exercise session during each intervention condition within the 14-day study period

Study Arms (5)

Run Before Breakfast

EXPERIMENTAL

Participants complete a 45 minute outdoor run beginning 60 minutes before the standardized breakfast time (08:00). A short recovery period is allowed between completion of exercise and meal initiation. Postprandial glucose responses are assessed following breakfast, lunch (13:00), and dinner (18:00).

Behavioral: Timed Endurance Exercise

Run After Breakfast

EXPERIMENTAL

Participants complete a 45 minute outdoor run beginning 90 minutes after the start of breakfast (08:00). Postprandial glucose responses are assessed following breakfast, lunch (13:00), and dinner (18:00).

Behavioral: Timed Endurance Exercise

Run Before Dinner

EXPERIMENTAL

Participants complete a 45 minute outdoor run beginning 60 minutes before the standardized dinner time (18:00). Postprandial glucose responses are assessed following dinner on the same day and following breakfast (08:00) and lunch (13:00) on the subsequent day.

Behavioral: Timed Endurance Exercise

Run After Dinner

EXPERIMENTAL

Participants complete a 45 minute outdoor run beginning 90 minutes after the start of dinner (18:00). Postprandial glucose responses are assessed following dinner on the same day and following breakfast (08:00) and lunch (13:00) on the subsequent day.

Behavioral: Timed Endurance Exercise

No Exercise Control

EXPERIMENTAL

Participants do not perform structured exercise on this study day and follow the standardized meal schedule. This condition serves as a within participant control. Postprandial glucose responses are assessed following breakfast (08:00), lunch (13:00), and dinner (18:00).

Behavioral: No Exercise Control

Interventions

Timed Endurance Exercise BEHAVIORAL

The exercise intervention consists of a 45 minute continuous outdoor run performed on a standardized route. Participants are instructed to maintain a consistent running pace across all exercise conditions. Exercise intensity is standardized using a target heart rate corresponding to 75 to 85 percent of maximal heart rate, and participants must be able to complete 45 minutes of continuous running at this intensity without stopping. Heart rate, duration, distance, and pace are recorded using a heart rate monitor and GPS enabled device. Ambient temperature and precipitation are recorded for each session. Exercise sessions may be rescheduled in cases of extreme weather or acute illness.

Run After Breakfast; Run After Dinner; Run Before Breakfast; Run Before Dinner

No Exercise Control BEHAVIORAL

This intervention involves a non-exercise control condition

No Exercise Control

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• Technical University of Munich: lead

Study Sites (1)

Technical University of Munich

München, Bavaria, 80809, Germany

RECRUITING

Study Officials

• Christoph Höchsmann, PD Dr.

  Technical University of Munich

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Christoph Höchsmann, PD Dr.

CONTACT

+49 89 289 24488; christoph.hoechsmann@tum.de

Karsten Köhler, Prof. Dr.

CONTACT

karsten.koehler@tum.de

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: OTHER
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Prof. Dr. Karsten Köhler

Study Record Dates

• First Submitted: February 12, 2026
• First Posted: February 25, 2026
• Study Start: April 1, 2026
• Primary Completion (Estimated): August 1, 2026
• Study Completion (Estimated): August 1, 2026
• Last Updated: April 20, 2026

Record last verified: 2026-04

Locations

DE (1)