I'm reading the BFL book again (read it before but never actually DONE it), and I love the idea of HIIT for good, hard cardio.

My question is - is it possible to do HIIT in the pool? I have recently started swimming and while I'm not great with my technique, when I push myself, I definitely end up breathing harder and if I were able to tell if I was sweating, I think I would be! Can I use swimming as HIIT once a week or so, or is it really only effective in running, biking, etc? Sounds like a dumb question, I know, but I can't find anything that says swimming would be OK for this type of cardio.

Thanks for any input!

You can certainly do it in the pool. Swimmers use it for training all the time. The big pace clocks on the wall really help with this as well.