So, I play a fair amount of squash. I try and play 3-4 times a week and I would generally play for 40 minutes x 2 each session, and in some instances I might play for over 1.5 hours. I can't recall the last time I had sore muscles. 

Last night I played in a tournament, and with due respect to my opponent, it was a comfortable victory to me, with me beating him 3-0 and only one of those games being close-ish. At the end of the match I was barely sweating. 

Today I have sore legs and my chest muscles around my right arm are moderately sore. 

Why would that be?

I wondered it was stress, but then other than a little before the game, I wouldn't say I found the occasion nearly as stressful as I might have found previous tournaments. 

I wouldn't say I am very fit, but I would say my body is used to playing squash. Even with a recent 3 week break from squash, my two hour return didn't result in sore musles. 

I am just curious.