I am in my 6th month of pregnancy right now and would kill for a fartlek. Sounds strange, but I would love mile repeats, 3x15 intervals on the bike and a hard, hard swim that leaves my ears throbbing. (always a sign, for me, that I swam hard.) I am dying to soak my shirt, front and back and have my legs dripping with sweat and to hang my head, hands on my knees, with exhaustion.
Really don't want a drink, don't want to eat sushi, don't want any of those other pregnancy taboos. (although I do miss goat cheese).
What I want is pure, physical exhaustion from an awesome workout. A definite pregnancy no-no.
Although, this kicking in my belly is pretty cool, too. A suitable substitute until August. :)