Things I learnt though? If you can't really do lunges or squats, you'll get given lots of push ups to do. 4 lots of 3x30 second sets make for sore, sore arms the next day. And the day after.
I love the pain and the accomplishment of still being sore. Even though I whine like a little bitch, I wouldn't change it for a thing.
Not being able to move my arms too much after that meant I could then sit on the exercise bike for 25 mins reading 50 Shades of Grey, along with the other 75% of the female population. Awesome :-D