Related Experiment Video
Updated: Aug 12, 2026
12:37
Surgical Placement of Catheters for Long-term Cardiovascular Exercise Testing in Swine
Published on: February 9, 2016
Cardiac dimensions and performance after either arm or leg endurance training
Medicine and Science in Sports and Exercise
|January 1, 1981
Summary
Short-term endurance training improves cardiac function, enhancing exercise performance even in untrained limbs. This cardiac improvement is partly independent of autonomic nervous system control and muscle adaptations.
Area of Science:
- Exercise Physiology
- Cardiovascular Physiology
- Sports Science
Background:
- Previous research demonstrated improved exercise performance in untrained limbs following unilateral arm or leg endurance training.
- Short-term endurance training's effects on cardiac function, particularly during exercise, require further elucidation.
Purpose of the Study:
- To investigate the impact of short-term unilateral endurance training on cardiac function at rest and during exercise.
- To differentiate between autonomic and non-autonomic contributions to training-induced cardiac adaptations.
Main Methods:
- Ten healthy men underwent 11 weeks of either arm or leg endurance training.
- Echocardiography and systolic time intervals (STIs) were used to assess cardiac function at rest and during trained/untrained limb exercise.
- Studies were repeated following autonomic blockade (atropine and propranolol).
Main Results:
- Training minimally affected resting cardiac size or performance, but leg training increased cardiac mass post-blockade.
- Resting left ventricular ejection time (LVET) was prolonged in the combined training groups post-blockade.
- During submaximal exercise, LVET increased significantly with and without autonomic blockade, suggesting enhanced stroke volume.
Conclusions:
- Short-term endurance training improves cardiac function during exercise, leading to enhanced performance.
- These cardiac improvements appear to be partially independent of autonomic nervous system adjustments and trained skeletal muscle adaptations.
- Findings suggest a direct effect of training on the heart's contractile function or efficiency.
Related Concept Videos
01:27Exercise and Muscle Performance
Exercise induces a range of adaptations in muscle tissue, depending on the type and duration of activity. Such physical training can be broadly categorized into two types: endurance exercises and resistance exercises.
Endurance exercises
Endurance exercises involve running, swimming, or cycling, which require repetitive movements with low force output. When a person engages in endurance exercise, a few noticeable changes occur in their skeletal muscles. For instance, the number of capillaries...
Endurance exercises
Endurance exercises involve running, swimming, or cycling, which require repetitive movements with low force output. When a person engages in endurance exercise, a few noticeable changes occur in their skeletal muscles. For instance, the number of capillaries...
01:29Pathophysiology of Cardiac Performance
Typical heart performance is influenced by heart rate, rhythm, myocardial contraction, and metabolism or blood flow. The cardiac muscle exhibits distinct electrophysiological features, including pacemaker activity and calcium channel control, which play a vital role in the heart's response to various drugs. The autonomic nervous system, comprising the sympathetic and parasympathetic branches, regulates heart rate. Sympathetic activation increases heart rate, while parasympathetic activation...
01:11Cardiac Output and Stroke Volume
Cardiac output (CO) is an integral aspect of human physiology, reflecting the heart's efficiency and responsiveness to the body's needs. It represents the volume of blood that the left or right ventricle ejects into the aorta or pulmonary trunk each minute. The CO is calculated by multiplying the heart rate (HR)—the number of heartbeats per minute—by the stroke volume (SV)—the amount of blood pumped out with each heartbeat.
In an average resting adult male, the typical cardiac output averages...
In an average resting adult male, the typical cardiac output averages...
01:17Exercise and Cardiac Output
Regular physical activity is essential for maintaining cardiovascular health, with aerobic exercises being particularly effective. According to the American Heart Association, 150 minutes of moderate to intense aerobic exercise per week is recommended for a healthy heart. Aerobic activities may include brisk walking, running, bicycling, cross-country skiing, and swimming, ideally performed three to five times per week.
Sustained exercise increases the muscles' oxygen demand, which can be met...
Sustained exercise increases the muscles' oxygen demand, which can be met...
01:20Exercise and Cardiovascular Response
Exercise significantly impacts cardiovascular response, which is crucial for understanding patient health and designing effective treatment plans.
Light to moderate physical activity initiates a series of interconnected responses in the body. The heart rate modestly increases in anticipation of the workout, followed by widespread vasodilation as oxygen consumption by skeletal muscles increases. This results in decreased peripheral resistance, increased capillary blood flow, and accelerated...
Light to moderate physical activity initiates a series of interconnected responses in the body. The heart rate modestly increases in anticipation of the workout, followed by widespread vasodilation as oxygen consumption by skeletal muscles increases. This results in decreased peripheral resistance, increased capillary blood flow, and accelerated...
01:22Cardiac Output II: Effect of Stroke Volume on Cardiac Output
Cardiac output (CO), the amount of blood the heart pumps per minute, is a parameter in cardiovascular physiology determined by stroke volume and heart rate. Stroke volume, the amount of blood pushed from one of the ventricles per heartbeat, is influenced by preload, afterload, and contractility.
Preload
Preload refers to the initial elongation of the cardiac myocytes before contraction and is related to the volume of blood filling the heart at the end of diastole, or end-diastolic volume. The...
Preload
Preload refers to the initial elongation of the cardiac myocytes before contraction and is related to the volume of blood filling the heart at the end of diastole, or end-diastolic volume. The...