Your temperature rises. Muscles need energy in order to workout, so your body burns calories from the fats and carbohydrates that you eat in a series of chemical reactions that produce heat.
Your heart gets stronger. Exercise increases your heart rate and helps pump more blood through your system, which is also what raises your core temperature. Regular exercise makes your heart stronger and more efficient. Over time it reduces your resting heart rate by 5-25 beats per minute.
Endorphins are released. When you exercise, your body releases chemicals called endorphins. Endorphins then interact with the receptors in your brain to reduce your perception of pain. Endorphins also trigger a happy feeling within your body that are accompanied by a more positive outlook on life.
Brain function improves. Getting your heart rate up improves blood flow to the brain, which helps your brain immediately function better. Studies found that exercising increases the size of the hippocampus, which is associated with memory and learning. Therefore, regular exercise helps prevent the onset of dementia and Alzheimer’s.

[/quote][quote=Kaffy2001]Your temperature rises. Muscles need energy in order to workout, so your body burns calories from the fats and carbohydrates that you eat in a series of chemical reactions that produce heat.
Your heart gets stronger. Exercise increases your heart rate and helps pump more blood through your system, which is also what raises your core temperature. Regular exercise makes your heart stronger and more efficient. Over time it reduces your resting heart rate by 5-25 beats per minute.
Endorphins are released. When you exercise, your body releases chemicals called endorphins. Endorphins then interact with the receptors in your brain to reduce your perception of pain. Endorphins also trigger a happy feeling within your body that are accompanied by a more positive outlook on life.
Brain function improves. Getting your heart rate up improves blood flow to the brain, which helps your brain immediately function better. Studies found that exercising increases the size of the hippocampus, which is associated with memory and learning. Therefore, regular exercise helps prevent the onset of dementia and Alzheimer’s.

every human needs it

That's fantastic