Effects of Acute Exercise in Fasting and Fed States in Individuals With Different Aerobic Fitness Levels
Trial statusNot yet recruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexMale
Age18-25
SponsorHacettepe University
About this trial
The aim of this study is to investigate the effects of aerobic fitness level, feeding status, and acute exercise on whole-body metabolic fuel utilization and mitochondrial function in peripheral blood mononuclear cells (PBMCs) in healthy young men.
The main questions it aims to answer are:
1. Do individuals with high and low aerobic fitness levels differ in fat and carbohydrate oxidation at rest and during exercise following an overnight fast, and do their PBMC mitochondrial responses to acute exercise differ? 2. Does feeding alter fat and carbohydrate oxidation at rest and during exercise compared with the fasted state in individuals with high aerobic fitness? 3. Are PBMC mitochondrial respiration parameters and their exercise-induced changes associated with fat and carbohydrate oxidation during fasted exercise?
Eligibility criteria
This trial accepts healthy volunteersQualifiers
Healthy male volunteers aged 18-25 years
Body mass index between 18.5 and 24.9 kg/m²
Residing on the Hacettepe University Beytepe Campus
Eligibility for one of the following aerobic fitness groups
Disqualifiers
Current smoking
Regular or excessive alcohol consumption
Any musculoskeletal condition that may limit or prevent exercise
Allergy to any of the foods provided as part of the study meal
Trial design
Design model
Parallel
Treatments tested in this trial
Acute Moderate-Intensity Cycling Exercise
BehavioralParticipants will perform 30 minutes of continuous cycling exercise on a cycle ergometer at an intensity corresponding to 65% of their individual maximal oxygen uptake (VO2max). Both aerobic fitness groups will complete the exercise following an overnight fast. Participants in the high aerobic fitness group will also repeat the exercise one hour after consuming an ad libitum meal. Respiratory gas exchange will be measured throughout exercise to calculate fat and carbohydrate oxidation, and rating of perceived exertion will be recorded every five minutes using the Borg 6-20 scale.
Ad Libitum Mixed Meal
Other interventionOne hour after completing the fasted exercise test, participants in the high aerobic fitness group will be provided with an ad libitum mixed meal consisting of pasta and meatballs and will be allowed to eat until comfortably full. One hour after the meal, resting metabolic rate measurement and the 30-minute cycling exercise test at 65% of VO2max will be repeated under the fed condition. No blood samples will be collected during the fed condition.
Treatment groups
30 Participants
are divided into 2 treatment groupsGroup A: High Aerobic Fitness: Fasted and Fed ConditionsExperimental treatment 2 interventions
Group B: Low Aerobic Fitness: Fasted ConditionOther 1 intervention
Trial outcomes
Primary outcomes
1
Change in PBMC Mitochondrial Oxygen Consumption Rate From Pre- to Post-Exercise
Mitochondrial oxygen consumption rate (OCR) will be measured in peripheral blood mononuclear cells (PBMCs) using a Seahorse XFe96 extracellular flux analyzer. PBMCs will be isolated from venous blood samples collected immediately before and immediately after the fasted 30-minute submaximal cycling test. Pre- to post-exercise changes in OCR will be evaluated between the high and low aerobic fitness groups and examined in relation to whole-body fat and carbohydrate oxidation during exercise.
Time frame
Immediately before and immediately after the fasted 30-minute cycling test at 65% of VO2max.2
Change in PBMC Proton Efflux Rate From Pre- to Post-Exercise
Proton efflux rate (PER) will be measured in peripheral blood mononuclear cells (PBMCs) using a Seahorse XFe96 extracellular flux analyzer. PBMCs will be isolated from venous blood samples collected immediately before and immediately after the fasted 30-minute submaximal cycling test. Pre- to post-exercise changes in PER will be evaluated between the high and low aerobic fitness groups and examined in relation to whole-body substrate oxidation during exercise.
Time frame
Immediately before and immediately after the fasted 30-minute cycling test at 65% of VO2max.3
Fat Oxidation Rate During Submaximal Exercise
Whole-body fat oxidation rate, expressed in grams per minute (g/min), will be calculated using the Frayn stoichiometric equation from oxygen consumption (VO2) and carbon dioxide production (VCO2) measured by indirect calorimetry during 30 minutes of cycling at 65% of the participant's individual VO2max. Fat oxidation will be compared between the high and low aerobic fitness groups under fasted conditions and between the fasted and fed conditions within the high aerobic fitness group.
Time frame
During each 30-minute submaximal cycling test performed at 65% of VO2max.4
Carbohydrate Oxidation Rate During Submaximal Exercise
Whole-body carbohydrate oxidation rate, expressed in grams per minute (g/min), will be calculated using the Frayn stoichiometric equation from oxygen consumption (VO2) and carbon dioxide production (VCO2) measured by indirect calorimetry during 30 minutes of cycling at 65% of the participant's individual VO2max. Carbohydrate oxidation will be compared between the high and low aerobic fitness groups under fasted conditions and between the fasted and fed conditions within the high aerobic fitness group.
Time frame
During each 30-minute submaximal cycling test performed at 65% of VO2max.Secondary outcomes
1
Resting Fat Oxidation Rate
Resting fat oxidation rate, expressed in grams per minute (g/min), will be calculated from oxygen consumption (VO2) and carbon dioxide production (VCO2) measured by indirect calorimetry during the resting metabolic assessment. Resting fat oxidation will be compared between the high and low aerobic fitness groups under fasted conditions and between the fasted and fed conditions within the high aerobic fitness group.
Time frame
During the resting metabolic assessment before the fasted and fed exercise conditions.2
Resting Carbohydrate Oxidation Rate
Resting carbohydrate oxidation rate, expressed in grams per minute (g/min), will be calculated from oxygen consumption (VO2) and carbon dioxide production (VCO2) measured by indirect calorimetry during the resting metabolic assessment. Resting carbohydrate oxidation will be compared between the high and low aerobic fitness groups under fasted conditions and between the fasted and fed conditions within the high aerobic fitness group.
Time frame
During the resting metabolic assessment before the fasted and fed exercise conditions.3
PBMC Glycolytic Proton Efflux Rate (glycoPER)
Glycolytic proton efflux rate (glycoPER) will be calculated from the total proton efflux rate after correction for the mitochondrial contribution to extracellular acidification. Measurements will be obtained from PBMCs isolated from venous blood samples collected immediately before and immediately after the fasted submaximal exercise test using a Seahorse XFe96 extracellular flux analyzer.
Time frame
Immediately before and immediately after the fasted 30-minute cycling test at 65% of VO2max.4
Resting Metabolic Rate
Resting metabolic rate, expressed in kilocalories per day (kcal/day), will be measured using a Q-NRG indirect calorimetry system in canopy mode. Measurements will be performed after an overnight fast in both aerobic fitness groups. In the high aerobic fitness group, resting metabolic rate will also be reassessed one hour after the ad libitum meal and before the fed exercise test.
Time frame
Before fasted exercise in both groups and 1 hour after the meal before fed exercise in the high-fitness group.Other outcomes
1
Rating of Perceived Exertion During Submaximal Exercise
Perceived exertion will be rated using the Borg 6-20 scale during each 30-minute submaximal cycling test. Higher scores indicate a greater perceived level of exercise intensity and effort.
Time frame
Every 5 minutes during each 30-minute submaximal cycling test.2
Ad Libitum Energy Intake
Total energy intake will be determined from the amount of the standardized pasta-and-meatball meal consumed ad libitum by participants in the high aerobic fitness group. The meal will be prepared using standardized recipes and ingredient quantities to allow quantification of the energy consumed.
Time frame
During the ad libitum meal provided 1 hour after completion of the fasted exercise test.Sponsors and contacts
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Source ClinicalTrials.gov
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