EXERCISE SUBSTRATE UTILIZATION--THE CROSSOVER CONCEPT

运动基质的利用——交叉概念

• 批准号: 2082439
• 负责人: GEORGE Austin BROOKS
• 金额: $ 31.06万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-07-15 至 1997-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2082439
• 关键词: EXERCISE; SUBSTRATE; UTILIZATION; CROSSOVER; CONCEPT

Our overall objective is to identify and understand the factors which control the balance of energy derived from endogenous carbohydrate (CHO) and lipid utilization during sustained, submaximal exercise. The theoretical basis of our approach is the "crossover" concept which we develop fully in our text. Simply put, we believe that during rest and mild to moderate intensity exercise, lipids provide the greatest proportion of energy for exercise. However, as the exercise increases from moderate to hard to maximal, the balance of substrate utilization switches, or 'crosses over' from lipid to carbohydrate. The "Crossover Point" is identified as the power output at which carbohydrate-derived fuels predominate over lipids as energy sources with further increases in power eliciting proportional increments in carbohydrate utilization and decrements in lipid utilization. We further believe that while prior exercise (endurance training) enhances the ability to utilize lipids during mild to moderate intensity exercise, crossover to carbohydrate dependence inevitably occurs in the transition from moderate intensity to hard exercise, crossover to carbohydrate dependence inevitably occurs in the transition from moderate intensity to hard exercise, even in the trained state. In pursuit of our overall objective, we propose to explore five specific aims. These are to: (1) describe the effects of exercise intensity on the balance of energy derived from glucose and free fatty acid (FFA) utilization, (2) described the effects of endurance training on this balance, (3) explore the role of the sympathetic nervous system (SNS), specifically epinephrine, in controlling this balance during exercise, (4) evaluate the role of lactate as a metabolic intermediate, and (5) evaluate the possibility that women may differ from men in their metabolic response to exercise and exercise training. To address these aims, we propose to study men and women at rest and during exercises of give absolute and relative intensities, both before and after long-term training. On men, we plan to also to utilize short- term endurance training, as well as beta-adrenergic blockade in an attempt to dissect sympathetic from other training-induced adaptations on the balance of substrate supply during exercise. Techniques of indirect calorimetry, primed-continuous stable isotope infusion, muscle biopsies and measurements of leg arterial-venous difference [(a-v)] and blood flow as well as response of glucoregulatory hormones will be used to address the above indicated specific aims.

我们的总体目标是识别和理解哪些因素 控制来自内源性碳水化合物（CHO）的能量的平衡 和持续下次运动过程中的脂质利用。 这 我们方法的理论基础是我们的“交叉”概念 在我们的文本中充分发展。 简而言之，我们相信在休息期间 轻度至中度强度运动，脂质提供最大的 锻炼能量的比例。 但是，随着练习的增加 从中等到最大，底物利用率的平衡 开关或从脂质到碳水化合物“交叉”。 “跨界” 点“被确定为碳水化合物衍生的功率输出 燃料以脂质为主，作为能源，进一步增加 在碳水化合物利用率中提出比例增量的功率 并减少脂质利用率。 我们进一步相信，虽然之前 运动（耐力训练）增强了使用脂质的能力 在轻度至中度强度锻炼中，交叉到碳水化合物 依赖性不可避免地发生在中等强度的过渡中 为了努力锻炼，不可避免地会发生交叉依赖碳水化合物的依赖性 在从中等强度到艰苦锻炼的过渡中，即使在 受过训练的状态。 为了追求我们的整体目标，我们建议探索五个特定的特定目标 目标。 这些是：（1）描述运动强度对 来自葡萄糖和游离脂肪酸（FFA）的能量平衡 利用率，（2）描述了耐力训练对此的影响 平衡，（3）探索交感神经系统（SNS）的作用， 特别是肾上腺素，在锻炼过程中控制这种平衡时， （4）评估乳酸作为代谢中间体的作用，（5） 评估女性可能与男性有所不同的可能性 对运动和运动训练的代谢反应。 为了解决这些目标，我们建议在休息和女性中研究男人和女人 在练习绝对强度和相对强度的过程中 经过长期培训。 关于男人，我们计划还要利用短暂的 任期耐力培训以及β-肾上腺素能封锁 试图从其他训练引起的适应中解剖同情 在运动过程中的基板供应平衡。 技术的技术 间接量热法，底漆连续稳定的同位素输注，肌肉 活检和腿部动脉差异的测量[（A-V）]和 血流以及葡萄糖调节激素的反应将被使用 解决上述指示的特定目标。