I have an intense longing to return to Hawaii.
Piercing
well if you have a knife cut and one would say it was intense: it would be severe bleeding
Cardio is basically eveyrthing that gets you breathing hard and your heart rate up. Intense cardio is anything that will get your heart rate and breathing really up there.
ACT fluoride rinse is great for your teeth because it helps with sensitivity and preventing cavities. Not intense at all =)