so ive been doing hiit almost everyday for the past month or so, and initially i noticed results pretty quickly but for the past week it seems that im not getting any results Could it be the way i do hiit? I generally just run flat out for 30 seconds and just walk around until i feel up for another sprint (the rest intervals usually start at 30 seconds and become longer, sometimes up to 2mins or so -- cause im weaksauce). I usually do 6 cycles. Is it really important to keep the rest cycles at 30 seconds? If I try to keep the 30 second rest interval i think ill only be able to do 3/4 cycles before i collapse or something ive read that im supposed to keep a certain heart rate while doing the rest intervals -and im generally just walking around as opposed to light jogging. could this be making that much of a difference? also some sites suggest that starting out at 75% and increasing the intensity every cycle -- while i just start at 100% and try to keep it at 100% any help?