How does exercise affect the body

After exercise, you’ll find your body experiences immediate and more gradual effects. The minute you start training, you’ll notice more frequent muscle contraction, raised body temperature and pulse, and deeper breathing known as tidal volume. Longer-term effects occur as the body adapts to regular exercise, including your heart getting larger, bones becoming denser and the vital capacity of your breath deepening.

Bones, Joints and Muscles

Immediate effects when first exercising:

Muscles contract more often
Blood flow to muscles increases
Muscle temperature rises
Little effect on bones and joints

Effects of regular training:

Muscles increase in size (hypertrophy)
Muscular endurance improves
Muscles, tendons and ligaments around joints get stronger
Joints become more stable and flexibility at joints increases Bone width and density increases

A gymnast bent backwards.
(Flexibility at joints increases with regular training)

The Cardiovascular System ( Heart)

Immediate effects when first exercising:
Heart contracts more often – increased heart rate.
Heart contracts more powerfully – increased stroke volume, which is the volume of blood pumped from heart with each beat. Blood diverted to muscles, eg it is diverted from the digestive system to the muscles. Blood temperature rises.

Blood vessels near skin open to allow heat to be lost.
Effects of regular training:
Heart muscle increases in size and strength.
Cardiac output increases. Cardiac means relating to the heart so this is the amount of blood that the heart pumps out to the body. Lower resting heart rate, quicker recovery from exercise.
Reduced risk of heart disease.
Increased number of capillaries in muscles.
Increased volume of blood and red blood cells.

The Respiratory System (Lungs)
Immediate effects when first exercising:
Increased rate of breathing
Increased depth of breathing – rise in tidal volume

Effects of regular training:
As you exercise, your muscles warm up, and you feel sweat forming on your brow. Even your breath feels hot. Two ways your body regulates body temperature are perspiration and respiration. Your muscles need a steady flow of energy to keep working. Heat is created when your muscles make energy. Your body works hard to regulate this temperature change and keep you within a safe range. Increased strength of diaphragm and intercostal muscles.

Greater number of alveoli.
Increased ability of the lungs to extract oxygen from the air. Increased vital capacity.
Increased amount of oxygen delivered to, and carbon dioxide removed from, the body.

Body Temperature
Temperature Regulation:
Your hypothalamus is a cone-shaped area in your brain. It secretes hormones that regulate many of your body systems. One of these systems is your body temperature. The hypothalamus works as a thermostat for your body. Receptors in your body continually send messages to the hypothalamus about your temperature. Adjustments are made to keep your body temperature between 97.5 and 99.5 degrees Fahrenheit. Exercise and Body Temperature:

Your muscles quickly deplete stored energy when you start exercising. To make more energy, muscles combine oxygen with ATP. This process creates heat energy as a byproduct. Extra heat raises your body temperature, so your body needs to eliminate heat as quickly as possible. Temperature sensors tell the hypothalamus your body temperature is increasing, and something needs to lower it. During exercise, extra blood flows to your muscles to keep them going. When your body temperature starts to elevate, extra blood flows to your skin, so evaporation, or sweat, can help cool you off. Blood flow diverted from other organs, such as the kidney and liver, allows more blood to flow to your skin surface. Some of the extra heat picked up in the circulatory system is eliminated by respiration as you breathe out heated air.