Biology and Medicine

Physiological Responses to Physical Activity: Acute and Chronic Effect

Claudia Schunn^* Department of Medicine, University of California Santa Cruz, Santa Cruz, United States of America
^*Correspondence: Claudia Schunn, Department of Medicine, University of California Santa Cruz, Santa Cruz, United States of America, Email:

Received: 23-Oct-2024, Manuscript No. BLM-24-27596; Editor assigned: 25-Oct-2024, Pre QC No. BLM-24-27596 (PQ); Reviewed: 08-Nov-2024, QC No. BLM-24-27596; Revised: 15-Nov-2024, Manuscript No. BLM-24-27596 (R); Published: 22-Nov-2024, DOI: 10.35248/0974-8369.24.16.748

Description

Physical activity induces a wide range of physiological responses in the body. These responses can be categorized into acute effects, which occur immediately during or shortly after exercise and chronic effects, which develop over time with consistent exercise. Both types of responses are essential for understanding how the body adapts to different forms of physical exertion and how regular exercise promotes long-term health and fitness. Acute responses to exercise refer to the immediate changes the body undergoes during and immediately after a single bout of physical activity. These responses are largely compelled by the body's need to meet the increased demands for energy, oxygen and waste removal during exercise. Key systems that respond acutely to exercise include the cardiovascular, respiratory, muscular and endocrine systems.

When exercise begins, the cardiovascular system responds by increasing heart rate, stroke volume and cardiac output. These adjustments are necessary to deliver more oxygenated blood to the working muscles. The heart rate increases proportionally with exercise intensity and stroke volume increases as the heart pumps more blood per beat. The combined effect is an increase in cardiac output, which is the volume of blood the heart pumps per minute. Furthermore, vasodilation occurs in the muscles, increasing blood flow to areas with the greatest demand for oxygen. At the same time, vasoconstriction happens in less active areas of the body, redirecting blood flow to the muscles, heart and lungs. In response to physical activity, the respiratory system increases ventilation (the volume of air breathed in and out). During intense exercise, the oxygen demand may exceed the capacity of the lungs to extract oxygen from the air, leading to an increase in breathing rate to compensate. This is a vital response for maintaining aerobic energy production and preventing a buildup of metabolic byproducts such as lactic acid. Muscle activity is the core of exercise. When muscles contract they require increased energy, which is primarily provided by the breakdown of glucose and fatty acids. This process produces ATP (Adenosine Triphosphate), the energy currency of the cell. The increase in ATP demand leads to a greater utilization of both aerobic and anaerobic metabolic pathways, depending on the intensity and duration of the exercise. During exercise, muscles experience an increase in temperature due to the higher rate of energy expenditure. This increased temperature helps improve muscle flexibility and efficiency, but it also necessitates mechanisms to dissipate heat, such as increased blood flow to the skin and sweating.

The endocrine system responds to exercise by releasing hormones that help regulate metabolism and energy production. For instance, cortisol levels rise during exercise to help increase blood sugar levels, while epinephrine (adrenaline) and norepinephrine (noradrenaline) increase heart rate, blood pressure and the availability of energy substrates like glucose and fatty acids. Additionally, insulin secretion decreases during exercise, which helps mobilize energy stores from muscles and fat tissue. Chronic responses to exercise involve long-term adaptations that occur after repeated bouts of physical activity over weeks, months or even years. These adaptations allow the body to function more efficiently, improve physical performance and enhance overall health. Chronic exercise leads to changes in almost every physiological system in the body. Regular physical activity leads to improved cardiovascular function. One of the most significant adaptations is an increase in stroke volume, which means the heart can pump more blood per beat. This is due to an increase in the size of the heart’s chambers and the efficiency of the myocardium (heart muscle). Over time, cardiac output at rest and during submaximal exercise may improve, meaning that the heart does not need to work as hard to deliver oxygen to the muscles. Additionally, regular exercise leads to improved endothelial function and vasodilation. This helps to maintain healthy blood pressure and improves circulation, reducing the risk of hypertension and cardiovascular diseases.