After a good distance of running, you might have felt a sensation of happiness. That is the runner's high and some chemicals in your body cause it. Hosted by: Michael Aranda ---------- Support SciShow by becoming a patron on Patreon: https://www.patreon.com/scishow ---------- Dooblydoo thanks go to the following Patreon supporters—we couldn't make SciShow without them! Shoutout to Kevin Bealer, Mark Terrio-Cameron, KatieMarie Magnone, Patrick Merrithew, Charles Southerland, Fatima Iqbal, Sultan Alkhulaifi, Tim Curwick, Scott Satovsky Jr, Philippe von Bergen, Bella Nash, Chris Peters, Patrick D. Ashmore, Piya Shedden, Charles George ---------- Looking for SciShow elsewhere on the internet? Facebook: http://www.facebook.com/scishow Twitter: http://www.twitter.com/scishow Tumblr: http://scishow.tumblr.com Instagram: http://instagram.com/thescishow ---------- Sources: http://www.pnas.org/content/112/42/13105.full http://jeb.biologists.org/content/215/8/1331?sid%3D739917de-aaf2-469d-9f3a-ab04329720b7= http://www.sciencedirect.com/science/article/pii/S0306453011002873 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3104618/ Image Sources: https://commons.wikimedia.org/wiki/File:Anandamide_skeletal.svg https://commons.wikimedia.org/wiki/File:Beta-endorphin_1-9.png