threshold triggering the production of happy hormones 

?RGP came to town giving an invited lecture, staying 3-day hanging around, relaxing and chatting. One point came to mind.

What made you running 20 miles daily? I asked.

It all started to pass a threshold, triggering the production of happy hormones such as testosterone or oxytocin.  So, you're thrilled to get that like having sex. He said. 

What? Like having sex? How can you trigger that? I's curious. 

Magic of threshold: You can run 20 miles daily for three months, which trigger that threshold. He explained. 

Wow!  run 20 miles daily for three months? It's harder than having sex! I realized.

He smiled: Well, it's different though.
 

**

Oxytocin is a neuropeptide produced in the hypothalamus and secreted by the pituitary gland. Oxytocin is released during sex, childbirth and lactation to aid reproductive functions. This neuropeptide exerts multiple psychological effects, influencing social behavior and emotion.

Oxytocin is a powerful hormone that acts as a neurotransmitter in the brain. ... When we hug or kiss a loved one, oxytocin levels increase; hence, oxytocin is often called "the love hormone." In fact, the hormone plays a huge role in all pair bonding.

oxytocin. /??ks??t??s?n/ noun. a polypeptide hormone, secreted by the pituitary gland, that stimulates contractions of the uterus or oviduct and ejection of milk in mammals; alphahypophame: used therapeutically for aiding childbirth.

Define oxytocin: a pituitary octapeptide hormone C43H66N12O12S2 that stimulates especially the contraction of uterine muscle and the secretion of milk.

Oxytocin released into the bloodstream affects the uterus and lactation, but its release into defined regions of the brain also affects emotional, ...