Hi Samovar, you're welcome.
Yes, you do need to think again. Because you're second answer, as it stands, prevents you getting the 3rd answer (on alphabetic grounds), which is one of the crucial answers of the puzzle, being one of the 2 thematic locations.
So, for the 2nd clue think in terms of different types of exercise (demanding an oxygen debt or not), or different types of microbes. The last 4 letters are loosely defined as a 'cover' but more accurately, an item of clothing...