If you don't feel ready then don't do it my breathing after week one was still horrible but i figured i would try week 2 day 1 just to see what would happen and I did it. Oh yes I was huffing and puffin when I was done with each 90 sec. I was pleasently suprised. Just don't give up on yourself. If you feel you need to repeat week 1 then do it. But please don't do it just because your afraid to fail. We will always fail once in a while. We pick ourself es up and do it again