Muscle and Body Temperature Responses During Uphill and Downhill Running
试验速览
- 阶段
- 不适用
- 状态
- 撤回
- 入组人数
- 44
- 主要终点
- Perceived muscle pain (arm 3)
研究概览
简要总结
In animal models of thermoregulation (how the body regulates heat), heat-sensitive nerve cells that help regulate body temperature have been identified throughout the body (e.g. in muscles, viscera, and blood vessels, among others); however, in human thermoregulation models, only two locations are generally recognized: the core (brain) and the skin. The limited number of recognized locations in humans are likely due to the difficulty in testing these locations in humans, as these locations are typically identified in animals by sedating them, surgically opening them up, stimulating the area of interest with a hot or cold probe, and then measure thermoregulatory responses.
Based on the literature, the researchers believe that by having participants run at the same energy expenditure but at three different inclines (uphill, downhill and flat) on a treadmill, the researchers can independently alter muscle temperature, while keeping core and skin temperature the same. Additionally, recent studies have suggested that temperature has a greater role at regulating blood flow through muscle tissue than previously recognized. Because of this, the researchers aim to have a second arm of the study to see whether these differences in muscle temperature result in differences in post-exercise blood flow to the muscle.
Finally, downhill running is often used to study exercise-induced muscle damage, due to the greater breaking forces compared to flat land running. Because of this, a third study aim will be to examine the association between fitness level, body morphology and sex on exercise-induced muscle damage.
详细描述
Primary aim: To alter muscle temperature independently from core and skin temperature, to investigate the existence of temperature sensitive nerve cells in human muscle tissue.
In animal models of thermoregulatory control, multiple loci of thermal sensation have been identified, including in the muscle, veins in the skin and abdomen, spinal column, upper airway, abdominal wall, lower esophagus, stomach, and small intestine. In contrast to these animal models, in human models of thermoregulatory control, typically, only thermal inputs from the brain (usually represented as "core" temperature, with proxy measures taken at the esophagus, rectum, intestine, or aural canal) are considered, along with further inputs from the skin that modify the central brain signaling.
The limited number of recognized thermally sensitive locations in humans are likely not due to a truly small number of thermally sensitive loci, but rather, due to the difficulty in testing these locations in humans. Indeed, the typical model for identifying thermally sensitive locations in animals is to sedate them, surgically open them up, stimulate the area of interest with a hot or cold probe, and then measure thermoregulatory responses; a protocol that is clearly unacceptable in humans.
Supporting the idea that the lack of recognized thermally sensitive locations is due to testing limitations, rather than an actual non-existence of physical locations, the principal researcher on the current application (Dr. Morris) previously conducted a series of studies providing evidence for the existence of thermoreceptors in the human abdomen. Indeed, recent reviews regarding human thermoregulatory control have updated the number of thermally sensitive sites to include the abdomen.
In the present study proposal, the investigators believe to have identified a protocol which would identify another thermally-sensitive location: human skeletal muscle.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Basic Science
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 45 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •All participants must be healthy with no history of respiratory, metabolic, cardiovascular, blood pressure disease, or of diabetes and must not currently be on any medication related to these or any other conditions. Additionally, due to the potential dangers of elevated body temperatures to the unborn fetus, all female participants must not be pregnant and agree to not to attempt to become pregnant throughout their involvement in the study.
排除标准
- •Unhealthy, history of respiratory, metabolic, cardiovascular, blood pressure disease, or of diabetes, currently taking medications related to these or that have the possibility of impairing cardiovascular or thermoregulatory function. Any participants that are pregnant.
结局指标
主要结局
Perceived muscle pain (arm 3)
时间窗: Assessed 48 hours after the completing exercise
Self-reported on a 100 mm likert scale ranging from "no pain or discomfort" to "maximal pain and discomfort"
Muscle temperature
时间窗: Immediately after completing the intervention
Measured at 4 locations: vastus lateralis, bicep femoris, lateral gastrocnemius and deltoid
Whole-body sweat rate (arm 1)
时间窗: Immediately after completing the intervention
Measured pre and post exercise with a platform scale (accurate to 1 g)
Femoral blood flow (arm 2)
时间窗: 1 hour after completing the intervention
Measured using Ultrasound Doppler
Core temperature
时间窗: Immediately after completing the intervention
Measured by rectal and esophageal temperature
Skin temperature
时间窗: Immediately after completing the intervention
Measured at 8 sites using the ISO 9886 weighting system
Blood pressure (arm 2)
时间窗: 1 hour after completing the intervention
Measured using a standard blood pressure cuff and finger photoplethysmography
Plasma creatinine levels (arm 3)
时间窗: Assessed 48 hours after the completing exercise
Measured from blood taken from an ante cubital vein
Maximal voluntary contraction (arm 3)
时间窗: Assessed 48 hours after the completing exercise
The maximal force (in N) generated by the right leg during an isometric leg extension, with the knee at 90 degrees
次要结局
- Oxygen consumption(Average oxygen consumption over the 60 min of exercise)
- Local sweat rate(Average local sweat rate over the 60 min of exercise)
- Perceived exertion(Average perceived exertion over the 60 min of exercise)
- Skin blood flow(Average skin blood flow over the 60 min of exercise)
- Heart rate(Average heart rate over the 60 min of exercise)
- Thermal comfort(Average thermal comfort over the 60 min of exercise)