The regulation of integrative responses to exercise

研究目标我的研究项目的首要目标是了解人类对耐力运动的适应性。具体来说，我感兴趣的是描述将运动压力转化为改善骨骼肌和血液功能的系统。我也对了解骨骼肌和血液对相关运动和环境刺激的反应感兴趣。背景与休息相比，运动肌肉的能量消耗显著增加。为了产生这种能量，人类必须从环境中吸收额外的氧气，并将其输送到肌肉中，以燃烧更多的燃料（脂肪和糖）。通过定期训练，人类能够以更大的强度和更长的时间进行锻炼。这种增强的健康很大程度上是由于肌肉中燃烧燃料的线粒体密度增加和携带氧气的红细胞体积增加。这些适应发生的过程是复杂的，但都是由每次锻炼后出现的简短“信号”启动的。这些信号引起器官的逐渐变化，随着时间的推移，改善其功能。骨骼肌和血液在运动和环境刺激下发生变化的能力是显著的，但尚未完全了解。我的研究项目的长期目标是了解调节骨骼肌和血液对运动和氧气供应减少的适应性的系统。短期目标建立在我最近的进展基础上，重点是理解(1)单次锻炼后导致线粒体密度和红细胞体积增加的信号；(2)在多次锻炼后，线粒体密度和红细胞体积方面发生的适应。为了解决这些问题，我控制了运动的强度、持续时间、频率和模式，以及参与者呼吸的氧气浓度。所有的研究都将在人类志愿者中进行，并将骑自行车作为运动刺激。由于男性和女性都将被纳入骨骼肌研究，性别对线粒体密度的影响也可以确定。这项研究将产生关于人类适应运动过程的知识，并为培养未来的科学领袖提供机会。我们目前还不完全了解控制骨骼肌和血液对运动或环境刺激的反应能力的系统。这些研究将有助于回答这些问题，并建立新的框架来回答未来的问题。受训者将领导拟议的研究，并发展技术和所需技能，为他们在科学领域的高级职业生涯做好准备。我们的实验将为应用运动生理学和运动处方的创新方法提供基础。

RESEARCH GOALSThe overarching goal of my research program is to understand human adaptations to endurance exercise. Specifically, I am interested in characterizing the systems that convert the stress of exercise into improved skeletal muscle and blood function. I am also interested in understanding the responsiveness of skeletal muscle and blood to relevant exercise and environmental stimuli. BACKGROUNDEnergy expenditure is dramatically increased in exercising muscles compared to rest. To produce this energy, humans must take in additional oxygen from the environment and deliver it to their muscles to burn more fuel (fats and sugars). With regular training, humans are able to exercise at greater intensities and for longer durations. This increased fitness is largely the result of a greater density of fuel-burning mitochondria in the muscles and an increased oxygen-carrying red blood cell volume. The process through which these adaptations occur is complex, but is initiated by brief “signals” that occur in response to each bout of exercise. These signals provoke incremental changes in the organ that, over time, improve its function. The capacity for skeletal muscle and blood to change in response to exercise and environmental stimuli is remarkable, but it is not fully understood. The LONG-TERM OBJECTIVE of my research program is to understand the systems that regulate adaptations in skeletal muscle and blood in response to exercise and reduced oxygen availability. The SHORT-TERM OBJECTIVES build upon my recent progress and are focused on understanding (1) the signals that lead to increased mitochondrial density and red blood cell volume following a single exercise session; and (2) the adaptations that occur with respect to mitochondrial density and red blood cell volume following many exercise sessions. To address these questions, I manipulate the intensity, duration, frequency, and mode of exercise as well as the concentration of oxygen that participants breathe. All studies will be performed in human volunteers and will use cycling as the exercise stimulus. As both men and women will be included in skeletal muscle studies, the influence of sex on mitochondrial density can be determined as well.SIGNIFICANCEThis research will generate knowledge regarding the processes through which humans adapt to exercise, and provide opportunities to train future science leaders. We currently do not fully understand the systems controlling the capacities of skeletal muscle and blood to respond to exercise or environmental stimuli. These studies will help answer these questions and establish new frameworks to answer future questions. Trainees will lead the proposed studies and develop technical and desirable skills that will prepare them for advanced careers in science. Our experiments will provide the foundation for innovative approaches to applied exercise physiology and exercise prescription.