The word "sesh" is short for "session" and is commonly used to refer to a casual gathering or event where people come together to hang out, chat, or engage in a specific activity. Full definition
haha Just the other day my friend & I were bored in Walmart and went around having a mini photo sesh with various items in various parts of the store haha (glitterinc.com)
For example, I got an amazing full body workout with today's 10 minute sweat sesh in a hotel room, using the small space I had available — and you could do this anywhere you happen to be! (thebettyrocker.com)
I have recently started to exercise more and love putting on my headphones, and having a sweat sesh on the elliptical. (kaleandchocolate.com)