Originally Posted by Magdlyn
The burn is caused by lactic acid building up in your muscles.
The pleasure is your body's natural opiates, endorphins, being released in response to the pain of the workout. This is also known as a "runner's high." It generally occurs 20 minutes into a workout. This is why exercise can become addicting. Our body starts to crave that high.
Also, it's a large part of the reason some people are into spankings and floggings and other painful practices in the BDSM world. The pain of the impact changes to pleasure as endorphins are released.
Thank you for explaining more about this subject!~ I wanted to know more about what exactly happens during this.~
I love science!~ ^_^