Role of the Cardiovascular System and the Brain in Determining Individual Tolerance to Exercise

心血管系统和大脑在决定个体运动耐受性中的作用

• 批准号: RGPIN-2016-05078
• 负责人: Tschakovsky, Michael
• 金额: $ 2.55万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=615483
• 关键词: Role; Cardiovascular; System; Brain; Determining

How easy exercise feels for an individual can determine their willingness to participate in physical activity (tolerance for exercise). Being physically active is an important part of quality of life for Canadians. Understanding what contributes to an individual’s exercise tolerance is therefore important to establish. It is known that when a person exercises in environments where there is a reduced amount of oxygen, such as at altitude, exercise feels more difficult. This is explained by the fact that the supply of oxygen provided to muscle during exercise can determine how well the muscle functions. This supply depends on the small blood vessels inside exercising muscle widening to allow more blood flow, and the heart increasing its output of blood to the body. The current view is that if you are a young and healthy adult in normal oxygen environments your oxygen delivery is tightly matched to the demands of the exercising muscles and therefore is not determining your exercise tolerance. This view is based on research studies where the average response of a group is used to understand how this matching works when a person is exercising. However, in my laboratory we have recently discovered that a healthy young individual’s heart and blood vessel response might be inherently better or worse than another's at this matching. Not only that, but this might actually be a reason why one person feels a certain amount of exercise as more difficult than another person. However there is currently a very poor understanding of this individual difference phenomenon. Therefore, the specific objectives of this proposal I and my HQP will pursue are to A) Establish the existence of individual differences in exercising muscle blood vessel and heart responses to sustainable exercise, B) Demonstrate that these differences are closely linked to the oxygen levels in the muscle, C) Demonstrate that they contribute to exercise tolerance differences between individuals, D) Identify what mechanisms are different across individuals that explain this. Another possible contributor to how difficult (or not) exercise feels is how the brain senses the exertion of exercise. Research into which areas of the brain are involved in the perception of exertion and how this perception can be modified is only really beginning. A big problem for researchers has been that the best technique to monitor activity of the brain and identify how much and where this activity is (magnetic resonance imaging (MRI)) requires the head to be very still. This has required researchers to look at the brain immediately after, rather than during, exercise. We are developing a way of exercising that will overcome this problem. With this approach I and my HQP will pursue these specific objectives A) Map the brain responses during exercise that are related to perception of effort and B) Identify how the brain responses change when perceived exertion is made to increase or decrease.

一个人对运动的感受有多容易可以决定他们参与体育活动的意愿（对运动的耐受性）。身体活动是加拿大人生活质量的重要组成部分。因此，了解影响个人运动耐量的因素非常重要。众所周知，当一个人在氧气含量减少的环境中（例如在高海拔地区）锻炼时，锻炼会感觉更加困难。这是因为运动期间向肌肉提供的氧气供应可以决定肌肉功能的好坏。这种供应取决于内部小血管的运动，肌肉扩张以允许更多的血液流动，以及心脏增加向身体输出的血液。 目前的观点是，如果您是处于正常氧气环境中的年轻健康成年人，您的氧气输送量与运动肌肉的需求紧密匹配，因此不会决定您的运动耐量。这种观点基于研究，其中群体的平均反应被用来理解当一个人锻炼时这种匹配是如何发挥作用的。然而，在我的实验室中，我们最近发现，在这种匹配中，一个健康的年轻人的心脏和血管反应可能本质上比另一个人更好或更差。不仅如此，这实际上可能是一个人感觉一定量的运动比另一个人更困难的原因。然而，目前人们对这种个体差异现象的认识还很差。因此，我和我的 HQP 将追求的该提案的具体目标是 A) 确定运动中肌肉血管和心脏对可持续运动的反应存在个体差异，B) 证明这些差异与肌肉中的氧含量密切相关，C) 证明它们导致个体之间的运动耐量差异，D) 确定个体之间有哪些不同的机制可以解释这一点。 影响锻炼感觉有多困难（或不困难）的另一个可能因素是大脑如何感知锻炼的强度。关于大脑的哪些区域参与对用力的感知以及如何改变这种感知的研究才刚刚开始。研究人员面临的一个大问题是，监测大脑活动并确定活动强度和位置的最佳技术（磁共振成像 (MRI)）需要头部保持静止状态。这要求研究人员在运动后立即观察大脑，而不是运动期间。我们正在开发一种锻炼方法来克服这个问题。通过这种方法，我和我的 HQP 将追求以下具体目标：A）绘制运动期间与努力感知相关的大脑反应；B）确定当感知努力增加或减少时大脑反应如何变化。