The Effects of 8 Weeks of Lower Limb Heat Therapy, Moderate-intensity Cycling Exercise, or Both on Vascular Function in Young, Healthy Males and Females
概览
- 阶段
- 不适用
- 干预措施
- 未指定
- 疾病 / 适应症
- Endothelial Dysfunction
- 发起方
- McMaster University
- 入组人数
- 60
- 试验地点
- 1
- 主要终点
- Brachial artery endothelial function
- 状态
- 已完成
- 最后更新
- 3年前
概览
简要总结
This study will explore the effects of 8 weeks of local leg heat therapy, exercise training, or both on measures of vascular function, cardiorespiratory fitness, and muscle strength in young, healthy individuals. Participants will be allocated into either a control group that will maintain their regular physical activity habits; or into one of three training groups: heat therapy will involve lower limb warm water immersion, exercise training will involve moderate-intensity cycling, and combined training will involve both performed in sequential order.
详细描述
A between-groups interventional design will be used in a cohort of 80 young, healthy males and females 18-35 years old. Interested individuals will be invited to the lab for a screening and familiarization visit (1 hr), in which participants will be introduced to various lab testing protocols to ensure proper performance and tolerance during experimental data collection sessions. Participants will be randomized into one of four groups for an 8-week intervention period: (1) no training (CON), (2) lower limb heat therapy (HEAT), (3) moderate intensity cycling training (EX), or (4) combined training (HEATEX). CON will involve maintenance of regular physical activity habits. HEAT will involve 45 minutes of lower limb hot water immersion (42 °C) using a custom-made heating apparatus 3x/week. EX will involve of 45 minutes of cycling on an ergometer at 40-59% VO2reserve 3x/week. HEATEX will require participants to perform 3x/week of exercise training and heat therapy consecutively and in that order, such that each session is 90 minutes in duration. In total, all groups except CON will be expected to complete 24 intervention sessions. Vascular function will be characterized by measures of endothelial function, arterial stiffness, arterial structure, central hemodynamics, arterial blood flow and shear, and endothelial cell nitric oxide production. Muscle and metabolic adaptations will be characterized by measures of cardiorespiratory fitness, body composition, muscle strength and thickness, and fasting glucose and insulin. Inflammatory profile will be characterized by concentrations of interleukins, heat shock proteins, and cortisol. Thermal physiological adaptations will be characterized by measures of core and skin temperature and sweat rate. Perceptual responses will be characterized by measures of thermal comfort and sensation, calmness, alertness, mood, affect, and ratings of perceived exertion. Intervention adherence will be tracked throughout the intervention period. For the acute investigation (3-hr visit), outcome measures will be assessed before and immediately following the first and last training session. For the chronic investigation (2-hr visit), outcome measures will be assessed at weeks 0, 2, 4, 6, and 8 of the intervention period.
研究者
入排标准
入选标准
- •Apparently healthy (i.e., no cardiovascular, musculoskeletal, or metabolic disease)
- •18-35 years old
- •Recreationally and/or physically active
排除标准
- •History of cardiovascular, musculoskeletal, or metabolic disease
- •Regular smoking and/or vasoactive drug use
结局指标
主要结局
Brachial artery endothelial function
时间窗: Change in endothelial function from week 0 to 8
Flow-mediated dilation (FMD) is a measure of the ability of the artery to dilate in response to elevated shear stress, and represents endothelial function. For this technique, a pressure cuff will be wrapped around the forearm and then inflated to \~200 mmHg for 5 minutes to occlude blood flow through the artery site. Doppler ultrasound (Vivid q, GE Medical Systems, Horten, Norway) and a 12 MHz linear array probe will be used to measure artery diameter before cuff inflation (rest), before cuff deflation (ischemia), and for three minutes after cuff deflation (reactive hyperemia). Images of the BA will be collected in Duplex mode and obtained proximal to the antecubital fossa. FMD will be calculated using this formula: FMD% = ((peak diameter-baseline diameter)/baseline diameter) × 100%.
Arterial stiffness
时间窗: Change in arterial stiffness from week 0 to 8
Pulse wave velocity (PWV) is a measure of the speed at which a pulse travels between two superficial artery sites, and represents arterial stiffness. For this outcome, applanation tonometers (i.e., micromanometer-tipped probes) (SPT-301, Millar Instruments, Houston, Texas, USA) will be used to detect and transmit pulse pressure wave forms at the carotid, femoral, and dorsalis pedis or tibialis posterior arteries. PWV will be calculated between the carotid-femoral arteries and femoral-foot arteries to quantify central and peripheral arterial stiffness, respectively, using this general formula: PWV = distance/pulse transit time.
次要结局
- Cardiorespiratory fitness(Change in cardiorespiratory fitness from week 0 to 8)
- Body composition(Change in body composition from week 0 to 8)
- Muscle strength(Change in muscle strength from week 0 to 8)
- Metabolic blood markers(Change in metabolic markers from week 0 to 8)
- Core temperature(Change in core temperature from week 0 to 8)
- Endothelial cell nitric oxide production markers(Change in endothelial nitric oxide production from week 0 to 8)
- Heat shock protein mRNA and content(Change in heat shock proteins from week 0 to 8)