Effects of Fasted- Versus Fed-exercise on Metabolic Health in Physically Active Adults

Effects of Fasted- Versus Fed-exercise on Glucose, Lipid and Blood Pressure Responses in Physically Active Adults

The purpose of this study is to investigate whether the sequence meal and exercise (exercise before meal or exercise after meal) affects the postprandial metabolism.

Study Overview

• Status: Completed
• Conditions: Blood Pressure; Insulin Sensitivity; Lipid Profile; Substrate Oxidation; Glucose Levels
• Intervention / Treatment: Behavioral: Fasted-exercise; Behavioral: Fed-exercise

Detailed Description

In the 48 h prior to each main trial, participants were asked to refrain from performing any strenuous physical activity and from consuming alcohol/caffeine for 24 h prior to the main trials. A dietary record was completed 24 h before the first main trial and participants were asked to replicate this diet prior to their second main trial.

On main trial days, participants arrived at the laboratory between 8-9 am following a 12-hour fast. The entire experiment lasted a total of 375 minutes. After anthropometric measurements, participants rested on a bed for 20 minutes, during which expired gas samples were collected. During the initial 60 minutes, participants then either consumed a meal before exercise (ME) or after exercise (EM). Participants were asked to finish their breakfast within 10 minutes. In both the ME and EM treatments, participants walked on the treadmill at 6 km/h (for females) and 6.4 km/h (for males) for 30 minutes. Expired gas samples were collected during this time, heart rate (HR) was monitored every 5 minutes and ratings of perceived exertion (RPE) were recorded every 10 minutes. After a 2-hour rest, lunch was provided and consumed within 15 minutes. Participants then underwent a 3-hour observation period during the postprandial phase.

Measurement:

Blood pressure was measured every 30 minutes during the experiment using the OMRON HEM-7320 blood pressure monitor (OMRON Co., Ltd., Japan). Three measurements of blood pressure and pulse were taken, and these values were averaged to ensure that the two readings were within 5 mmHg of each other. If the two readings differed by more than 5 mmHg, additional readings were taken until the outlying measurement was excluded. Blood pressure and pulse were assessed with the individual in a semi-sitting position on the bed, ensuring the arm was properly positioned.

Blood samples were taken at 0, 30, 60, 75, 90, 105, 120, 150, 180, 195, 210, 225, 240, 255, 285, 315, 345, and 375 minutes. The samples were appropriately processed, frozen, and stored in the Exercise Physiology Laboratory refrigerator at the Gongguan Campus of National Taiwan Normal University.

Gas sampling was conducted five times during the experiment. Samples were collected upon arrival at the laboratory, during exercise, one hour after breakfast or exercise, one hour after lunch, and two hours after lunch to determine resting metabolic rate (RMR) and energy expenditure using substrate oxidation.

Subjective self-assessments of appetite and mood were taken at 0, 30, 60, 120, 180, 195, 255, 315, and 375 minutes using a Visual Analog Scale (VAS) ranging from 0 to 100.

• Study Type: Interventional
• Enrollment (Actual): 16
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Taiwan
  • Taipei, Taiwan
    • National Taiwan Normal University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

1. Age between 20 and 45 years
2. Regular walking habit of at least 7500 steps per day
3. Engage in continuous walking for at least 20 minutes on 2 or more days per week
4. Body Mass Index (BMI) ranging from 18.5 to 27 kg/m2
5. No habits of heavy drinking or smoking, or have quit smoking for at least 6 months
6. Absence of diabetes, cardiovascular, or metabolic-related disorders
7. Not currently taking prescription drugs, over-the-counter medications, or other supplements that may affect blood sugar, blood pressure, or metabolic changes
8. No current sports injuries or medical advice against exercise
9. No significant weight fluctuations in the past three months (within ±3% of usual body weight)
10. Not experiencing shift work or travel across time zones within the past six months
11. No current plans to change lifestyle habits and willing to adhere to the requirements of the study

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Fasted-exercise; Breakfast intake before 30 min walking	Behavioral: Fasted-exercise; Breakfast intake before 30 min brisk walking on a treadmill
Experimental: Fed-exercise; 30 min walking before breakfast intake	Behavioral: Fed-exercise; 30 min brisk walking on a treadmill before breakfast intake

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Glucose responses	Changes in glucose concentrations between trials	375 minutes
Insulin responses	Changes in insulin concentrations between trials	375 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Triacylglycerol responses	Changes in Triacylglycerol concentrations between trials	375 minutes
Blood pressure	Changes in blood pressure (e.g., diastolic and systolic blood pressure) between trials	375 minutes
Heart rate variability (HRV)	Changes in heart rate variability between trials	375 minutes
Cognitive function	Changes in cognitive function (e.g., Accuracy and reaction time) between trials	375 minutes
Visual Analog Scales (VAS)	Changes in VAS (e.g, appetite and mood) between trials	375 minutes

Collaborators and Investigators

• Sponsor: National Taiwan Normal University

Study record dates

Study Major Dates

• Study Start (Actual): April 4, 2024
• Primary Completion (Actual): November 27, 2024
• Study Completion (Actual): November 27, 2024

Study Registration Dates

• First Submitted: April 22, 2025
• First Submitted That Met QC Criteria: April 22, 2025
• First Posted (Actual): April 29, 2025

Study Record Updates

• Last Update Posted (Actual): May 2, 2025
• Last Update Submitted That Met QC Criteria: April 29, 2025
• Last Verified: April 1, 2025

More Information

Terms related to this study

• Keywords: Glucose control; Lipid oxidation; Fasted-exercise
• Additional Relevant MeSH Terms: Metabolic Diseases; Glucose Metabolism Disorders; Hyperinsulinism; Insulin Resistance
• Other Study ID Numbers: 202310HM014-2

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No