Right, it was water, some from sweating and some from burning glycogen which is stored with water. And actually 8 pounds isn’t all that extreme, oddly enough.
For reference here’s a runner’s forum where they’re talking about weight loss during marathons and other long runs. 8 pounds is about the norm. One guy mentions 15 pounds was considered the safe upper limit during his high school football practices.
https://www.letsrun.com/forum/flat_read.php?thread=3319287
Boy, my wife, who is an RN, was really pissed at me when I told her I lost that much weight in one game.
And I wasn’t skating like the guys playing out...those guys really DO get gassed. My thing was having to pick myself up of the ice with all that waterlogged goalie gear on, over and over and over again...I recall I was a bit shell shocked there.
My best friend used to play on my team years ago, and he said of all the things he has done, nothing gets him as gassed as playing an intense shift of ice hockey. Heh, he used to get pissed hearing people shooting the breeze on the bench after coming off the ice-I guess SOME people skate harder than others...
I used to give people stress tests years ago, and some people couldn’t walk on a treadmill. Before they had drugs to make their heart think it was under stress, you had to exercise them with an arm-ergometer (a bicycle pedal setup they “pedaled” with their arms) or you could have them step up and down off of a step made for that purpose.
It doesn’t sound like much, but you can actually get people’s heart rate up just by having them step up and back down repeatedly!