What happens inside your body when you exercise?

Have you ever wondered what happens to your body during a workout at the gym? Whether a person engages in exercise for weight loss, to stay healthy or simply for fun, exercise does change the body. Although we know that exercise is the key to hopefully a long and healthy existence, most of us don’t realise exactly what is going on behind the scenes. Here are some of those things:


We need energy to move our muscles and for this, we call on the sugar that is stored from food we’ve consumed, in the form of glycogen. This helps the muscles to contract and move. The body only has small stores of this energy, so is forced to take in more oxygen to make additional adenosine triphosphate. Without enough oxygen, lactic acid forms.

Very small tears occur in the muscles and this assists them to grow bigger and tougher when they heal. The soreness we feel after a workout is this process occurring and usually lasts a couple of days.

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During exercise, the heart rate increases as it circulates more oxygen around the body through blood. A heart will become more efficient at this process the more exercise a person does, meaning they can start to workout for longer periods and at a higher rate. Try a workout at a Gym Dublin like https://southsidegym.ie/


A body can use up to 15 times more oxygen when exercising. This is why exercise makes people breathe heavier and harder. A person’s breathing rate will go up until the muscles around the lungs cannot physically move any quicker. This maximum capacity is called VO and the higher a person’s VO max, the fitter they are.


This muscle can become fatigued from all the heavy breathing involved in exercise. As it grows tired, a spasm can occur and this is what some people believe causes the painful condition of getting a stitch. To help with stitch, deep breathing and stretching can lessen the discomfort during a workout.


The increase in blood flow during exercise has some great benefits for the brain. The blood flow makes the brain cells begin to function at a higher level, making people feel more alert as they workout and having greater concentration and focus afterwards.

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This isn’t the only benefit for the brain. Working out also triggers the chemical neurotransmitters in the brain to release endorphins. This is the feel-good chemical that gives people a high as they exercise. There is also a release of dopamine and glutamate which helps us to keep moving and a clever substance called gamma-aminobutyric acid that acts as a prohibitor for slowing things down. This is what helps a person to keep their movements controlled, regulated and smooth.

A boost in serotonin levels is yet another positive result of exercise on the brain. Serotonin is a neurotransmitter that helps to balance the mood, as well as ward off depression.