I haven't been feeling well for the last couple of days, I had an infection somewhere in my jaw that showed itself physically as toothache, but on an emergency visit to the dentist it appeared there was nothing amiss. Still, she drilled out a couple of my fillings and put something in to combat any infection, then closed them up. Still, it was painful, and I couldn't sleep well so was tired, and it was just work and rest. The only respite seemed to come from cycling to work, which was probably the endorphins kicking in.
Endorphins are chemicals generally produced by the brain, known as neurotransmitters. There are at least 20 different endorphins, each having a different role. With exercise, endorphins are released which make you feel better, and prolonged exercise can be strong enough to release enough to create a mild euphoria, the so called "runners high", which goes some way to explain the good feelings of Parish walkers despite the pain. Exercise endorphin release is different for everyone, and it has also been theorized that it increases with age, another possible reason why so many Parish walk finishers are in the so called "veteran" walkers group. Endorphins are also responsible for decreased feelings of pain, acting as they do on the opiate receptors of the brain and the nervous system in much the same way as morphine, although without the addictions. This goes some way to explaining my pain reduction when cycling to and from work.
As well as exercise, endorphins are released during times of stress, which is what happens during severe injury when no pain is felt. People who are injured in stressful situations often feel no pain, allowing them to get out of further danger, or help others. The pain only kicks in when the situation causing the stress is over and the endorphin levels reduce.
Whatever, exercise creates endorphins, which make you feel good. Eventually the body gets used to these feelings, making you want to exercise more. The bodies own mechanism for keeping us fit and healthy? Possibly, but it seems to work, exercise makes you healthy and happy, and more able to deal with stress.
Endorphins are also released by eating spicy food, and also chocolate, making them addictive by chemical means, meaning you have an excuse when you decide to go out for another curry or reach for that last Quality Street!