Vo2Max intervals progressions , why ?
Hi there, while doing Vo2Max sessions these day. I came to ask myself, why would i do 5x3 and then switch to 4x4 and then try doing 4x5 and eventually 5x5. why can't i keep simply doing 4x4 all the time and increase NP per interval if it allows. What are the benefits of Vo2Max progressions and how 4x4 is better than 5x5 ? I do understand that 5x5 yields 25 total mins, but with 4x4 I can output higher NP per intervals. Also, at the beginning it was hard even doing 5x3, but now it is survivable to do 4x4, so i see that there are some adaptations happened. Is it really as simple as the longer at the max O2 intake the better ? And if so, how do you recognize/feel you are at the max o2 intake and don't go harder in order not to blow up?