Overworking Masticatory muscles

I went to the eating house I wrote about here with colleagues of my temporary job again.
Today I ordered the menu which was labeled in front of me, a set meal of a beefsteak. While I was waiting I was with some kind of anxiety since I've heard both good and bad reputations about it, so I got reliefed to see that it looked alright, at least not overcooked as an article I read once on the Internet.
Actually it was really nice but one thing... I found that my jaw got tired from chewing at the very end of the meal. The meat wasn't so tough as it sounds here but anyway not so soft as well and the amount of 200g really worked...
Altoghether we had a nice dinner and nice time together.