When we exercise, endorphin is released in the body. Endorphin produces a positive feeling. Due to the release of this chemical, we feel like as if our pain has reduced and hence endorphin fall into the category of analgesics. Endorphin is released by several parts of the body including the brain and spinal cord and bind to the neuron receptor in the same way as a pain medicine does.
Hence, while doing exercise it is the endorphin which is released in the body to make us feel good.
