The Effect of Acute Exercise in the Fasted and Fed States on Peripheral Blood Mononuclear Cells and Metabolic Fuel Utilization in Individuals With Different Aerobic Fitness Levels
试验速览
- 阶段
- 不适用
- 状态
- 尚未招募
- 入组人数
- 30
- 试验地点
- 1
- 主要终点
- Change in PBMC Mitochondrial Oxygen Consumption Rate From Pre- to Post-Exercise
研究概览
简要总结
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:
- 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?
- Does feeding alter fat and carbohydrate oxidation at rest and during exercise compared with the fasted state in individuals with high aerobic fitness?
- Are PBMC mitochondrial respiration parameters and their exercise-induced changes associated with fat and carbohydrate oxidation during fasted exercise?
详细描述
This experimental study uses a mixed design incorporating both between- and within-subject comparisons to investigate the influence of aerobic fitness level, feeding status, and acute exercise on substrate oxidation and peripheral blood mononuclear cell (PBMC) mitochondrial function. Between-group comparisons will examine differences between individuals with high and low aerobic fitness under standardized fasted conditions, whereas within-subject comparisons of fasted and fed conditions will be performed in the high-fitness group. In addition, the repeatability of substrate oxidation measurements will be assessed in the high-fitness group.
A total of 30 healthy men aged 18-25 years with a body mass index (BMI) of 18.5-24.9 kg·m-² will be recruited. Participants will be classified into two groups according to maximal oxygen uptake (V̇O₂max). The high-fitness group will comprise 15 endurance-trained individuals with a V̇O₂max >55 mL·kg-¹·min-¹, whereas the low-fitness group will comprise 15 sedentary or physically inactive individuals with a V̇O₂max <45 mL·kg-¹·min-¹.
During the first laboratory visit, participants in both groups will undergo body composition assessment using dual-energy X-ray absorptiometry (DXA) and complete an incremental cycling test to determine V̇O₂max. Following sufficient recovery, participants will complete a 20-min familiarization cycling session at an intensity corresponding to 65% of V̇O₂max.
Participants in the high-fitness group will complete four laboratory visits in total. During the second and third visits, participants will arrive at the laboratory following an overnight fast. Resting metabolic rate (RMR) will be assessed, after which participants will complete 30 min of cycling exercise at 65% of V̇O₂max. These visits will be performed under identical standardized conditions to determine the repeatability of substrate oxidation measurements.
During the fourth visit, participants in the high-fitness group will arrive at the laboratory following an approximately 12-h overnight fast. RMR will first be assessed, followed by the collection of a venous blood sample immediately before exercise. Participants will then complete 30 min of cycling at 65% of V̇O₂max, and a second venous blood sample will be collected immediately after exercise. These samples will be used to assess exercise-induced changes in PBMC mitochondrial function under fasted conditions.
研究设计
- 研究类型
- Interventional
- 分配方式
- Non Randomized
- 干预模型
- Parallel
- 主要目的
- Basic Science
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 25 Years（Adult）
- 性别
- Male
- 接受健康志愿者
- 是
入选标准
- •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
- •High aerobic fitness group: maximal oxygen uptake (VO2max) greater than 55 mL/kg/min and regular participation in endurance training.
- •Low aerobic fitness group: VO2max lower than 45 mL/kg/min and sedentary or not regularly physically active
排除标准
- •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
- •Currently following a weight-loss or other restrictive diet
研究组 & 干预措施
High Aerobic Fitness: Fasted and Fed Conditions
Participants with a VO2max greater than 55 mL/kg/min who regularly perform endurance training will be assigned to this arm. Participants will complete two repeatability visits under overnight-fasted conditions, including resting metabolic rate measurement followed by 30 minutes of cycling at 65% of VO2max. During the main experimental visit, they will complete the same measurements in the fasted state, with venous blood samples collected immediately before and after exercise. They will subsequently consume an ad libitum meal, and one hour later, resting metabolic rate measurement and the cycling exercise test will be repeated in the fed state.
干预措施: Acute Moderate-Intensity Cycling Exercise (Behavioral)
High Aerobic Fitness: Fasted and Fed Conditions
Participants with a VO2max greater than 55 mL/kg/min who regularly perform endurance training will be assigned to this arm. Participants will complete two repeatability visits under overnight-fasted conditions, including resting metabolic rate measurement followed by 30 minutes of cycling at 65% of VO2max. During the main experimental visit, they will complete the same measurements in the fasted state, with venous blood samples collected immediately before and after exercise. They will subsequently consume an ad libitum meal, and one hour later, resting metabolic rate measurement and the cycling exercise test will be repeated in the fed state.
干预措施: Ad Libitum Mixed Meal (Other)
Low Aerobic Fitness: Fasted Condition
Participants with a VO2max lower than 45 mL/kg/min who are sedentary or physically inactive will be assigned to this arm. Participants will complete the fasted experimental condition only. Following an overnight fast, resting metabolic rate will be measured and a venous blood sample will be collected immediately before 30 minutes of cycling at 65% of VO2max. A second venous blood sample will be collected immediately after exercise. Participants in this arm will not complete the repeatability visits or the fed experimental condition.
干预措施: Acute Moderate-Intensity Cycling Exercise (Behavioral)
结局指标
主要结局
Change in PBMC Mitochondrial Oxygen Consumption Rate From Pre- to Post-Exercise
时间窗: Immediately before and immediately after the fasted 30-minute cycling test at 65% of VO2max.
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.
Change in PBMC Proton Efflux Rate From Pre- to Post-Exercise
时间窗: Immediately before and immediately after the fasted 30-minute cycling test at 65% of VO2max.
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.
Fat Oxidation Rate During Submaximal Exercise
时间窗: During each 30-minute submaximal cycling test performed at 65% of VO2max.
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.
Carbohydrate Oxidation Rate During Submaximal Exercise
时间窗: During each 30-minute submaximal cycling test performed at 65% of VO2max.
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.
次要结局
- Resting Fat Oxidation Rate(During the resting metabolic assessment before the fasted and fed exercise conditions.)
- Resting Carbohydrate Oxidation Rate(During the resting metabolic assessment before the fasted and fed exercise conditions.)
- PBMC Glycolytic Proton Efflux Rate (glycoPER)(Immediately before and immediately after the fasted 30-minute cycling test at 65% of VO2max.)
- Resting Metabolic Rate(Before fasted exercise in both groups and 1 hour after the meal before fed exercise in the high-fitness group.)
研究者
Suleyman Bulut
Assistant Professor
Hacettepe University