Time-of-Day Effects of Fasted Exercise on Energy Intake

NCT06947824 | Completed DMC

• 1 other identifier: MvE_FastEx
• Study Type: interventional
• Target: 35
• Locations: 1 country
• Sites: 1

Brief Summary

This trial's aim is to investigate the time-of-day effects (morning vs. evening) of fasted exercise on acute and 24h post-exercise energy intake. Specifically, we will compare the effects of fasted morning exercise (12h overnight fast) vs. fasted (6h and 12h) evening exercise on total energy intake during a post-exercise ad libitum test meal as well as on 24h (free-living) energy intake. The secondary aim is to assess subjective appetite ratings before, immediately after, and 30 min post-exercise (visual analog scale). Healthy men and women aged 18-30 years will be included.

Conditions

Health; Energy Intake; Eating Behaviors; Appetite

Outcome Measures

Primary Outcomes (1)

• Acute ad-libitum post-exercise energy intake (test meal)

  Acute post-exercise energy intake (kcal) will be measured objectively using a single-item ad libitum test meal occurring 30 minutes after each exercise session. The meal will consist of cheese pizza, offered in excess of individual daily energy requirements, and all food will be provided at once.

  30 minutes after exercise

Secondary Outcomes (5)

• 24h post-exercise energy intake

  24 hours post-exercise

• Subjective appetite measures

  before exercise, immediately after exercise, and 30 minutes after exercise

• Carbohydrate oxidation

  continuously throughout the 30-minute exercise bout

• Fat oxidation

  continuously throughout the 30-minute exercise bout

• Energy expenditure

  continuously throughout the 30-minute exercise bout

Other Outcomes (4)

• Blood glucose

  before exercise and immediately after exercise

• Blood lactate

  before exercise and immediately after exercise

• Breath ketones

  before and immediately after exercise

Study Arms (5)

Fasted Morning Exercise (12h AMEx)

EXPERIMENTAL

Exercise will take place in the morning, following a 12h overnight fast

Behavioral: Fasted Morning Exercise (12h)

Fasted Evening Exercise (6h PMEx)

ACTIVE COMPARATOR

Exercise will take place in the evening, following a 6h period of fasting

Behavioral: Fasted Evening Exercise (6h)

Fasted Evening Exercise (12h PMEx)

ACTIVE COMPARATOR

Exercise will take place in the evening, following a 12h period of fasting

Behavioral: Fasted Evening Exercise (12h)

Fed Morning Exercise (AMEx Fed)

ACTIVE COMPARATOR

Exercise will take place in the morning after consuming a small snack (30 min before exercise)

Behavioral: Fed Morning Exercise (AMEx Fed)

Fed Evening Exercise (PMEx Fed)

ACTIVE COMPARATOR

Exercise will take place in the evening after consuming a small snack (30 min before exercise)

Behavioral: Evening Fed Exercise (PMEx Fed)

Interventions

Fasted Morning Exercise (12h) BEHAVIORAL

A 30-minute exercise session will take place on a treadmill in the morning (7:00, \~1h after participants' habitual wake-up time), after a 12h overnight fast. The session will consist of 30 minutes of steady state cycling at 65% of VO2max, following a 5 min warm-up.

Fasted Morning Exercise (12h AMEx)

Fasted Evening Exercise (6h) BEHAVIORAL

A 30-minute exercise session will take place on a treadmill in the evening (19:00, exactly 12 hours after the morning session), after a 6h fasting period. The session will consist of 30 minutes of steady state cycling at 65% of VO2max, following a 5 min warm-up.

Fasted Evening Exercise (6h PMEx)

Fasted Evening Exercise (12h) BEHAVIORAL

A 30-minute exercise session will take place on a treadmill in the evening (19:00, exactly 12 hours after the morning session), after a 12h fasting period. The session will consist of 30 minutes of steady state cycling at 65% of VO2max, following a 5 min warm-up.

Fasted Evening Exercise (12h PMEx)

Fed Morning Exercise (AMEx Fed) BEHAVIORAL

A 30-minute exercise session will take place on a treadmill in the morning (7:00, \~1h after participants' habitual wake-up time), after consuming a small pre-exercise snack (30 min before exercise). The session will consist of 30 minutes of steady state cycling at 65% of VO2max, following a 5 min warm-up.

Fed Morning Exercise (AMEx Fed)

Evening Fed Exercise (PMEx Fed) BEHAVIORAL

A 30-minute exercise session will take place on a treadmill in the evening (19:00, exactly 12 hours after the morning session), after consuming a small pre-exercise snack (30 min before exercise). The session will consist of 30 minutes of steady state cycling at 65% of VO2max, following a 5 min warm-up.

Fed Evening Exercise (PMEx Fed)

Eligibility Criteria

• Age: 18 Years - 30 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• BMI of 18.5.0-30.0 kg/m2
• weight stability (≤2.5 kg weight change during the past 3 months)
• ability to exercise at a vigorous intensity for 30 minutes

You may not qualify if:

• pregnancy or breastfeeding
• smoking
• history of or current eating disorders
• medical condition or use of medication that could affect appetite or pose any contraindications to exercise
• As the menstrual cycle can cause fluctuations in food cravings and appetite, women of childbearing age were only eligible if they used hormonal contraceptives. To ensure constant exposure to exogenous estrogen and progestin throughout the study phase, participating women were further asked to use active hormone pills throughout the study period in both studies, a practice that is considered both safe and efficacious.

Sponsors & Collaborators

• Technical University of Munich: lead

Study Sites (1)

Technical University of Munich

Munich, Bavaria, 80809, Germany

Location

MeSH Terms

Conditions

Feeding Behavior

Condition Hierarchy (Ancestors)

Behavior, Animal; Behavior

Study Design

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

Study Record Dates

• First Submitted: April 14, 2025
• First Posted: April 27, 2025
• Study Start: April 1, 2025
• Primary Completion: November 30, 2025
• Study Completion: December 15, 2025
• Last Updated: February 6, 2026

Record last verified: 2025-07

Data Sharing

• IPD Sharing: Will share

Locations

DE (1)