Running, worse? Good luck with it you crazy lady. The thing I particularly like about the exercise bike is you get to do it sitting down. Have you got a buggy that lends itself to jogging?
Also, an hour and a half of tattooing is probably something relatively small or simple. My brother's most recent one, he had four full afternoon sessions before it was finished.
I felt pretty high during childbirth too, but I think that was to do with the drugs they gave me. 
As for night feeds at this age, it's more that as a general rule babies can theoretically cope overnight without a feed, whereas when they're tiny their stomachs hold so little they need topping up more often. If there's one thing being here has taught me though, it's that babies don't follow the rulebook!
Very nice tattoo, Plonky! I feel I should point out though, you've just linked us all to your full name and date of birth. Anyone feel like playing some Identity Theft?