ANATOMY

Detailed explanation-1: -When the muscles start to work, they need more oxygen so the respiratory system responds by getting more oxygen into the lungs. The blood carries greater amounts of oxygen and the heart responds to pump more oxygenated blood around the body. Immediate effects can be visible in hot, sweaty and red skin.

Detailed explanation-2: -As we start exercising heart rate increases and beats with greater force. Exercise makes the body work harder and therefore muscles require more oxygen to continue to work effectively. Heart rate is increase by the body releasing adrenaline – the hormone that signals the heart to pump faster and harder.

Detailed explanation-3: -When you are exercising, your muscles need extra oxygen-some three times as much as resting muscles. This need means that your heart starts pumping faster, which makes for a quicker pulse.

Detailed explanation-4: -Vigorous-intensity aerobic activity will cause your heart rate to increase significantly. You will find yourself breathing hard and fast, and find it hard to hold a conversation with someone. Examples of vigorous-intensity physical activity include: Jogging or running.