When a trainer tells you cardio/HIIT will increase cortisol levels, that should immediately tell you that their training approach is flawed.....
Part 1 of 2 Blogs to refute the #BS surrounding cardio/VO2 Max training, whilst highlighting why it's ESSENTIAL you include cardio based training into your fitness regime.
There are no if's but's or maybe's. You CAN'T increase your VO2 Max with weight training, and you CAN'T remove stubborn fat from the body from resistance training alone.
Understand our cells survive through their most basic need, oxygen. We have adapted many thousands of times over in order to best meet our most basic survival need. We crave cellular efficiency. That is achieved through maximising oxygen transportation capacity. This allows for more oxygen to be drawn from the air we breath thus available in our skeletal muscle. We will adapt at speed to ensure we can meet this demand so that we push back the need for suffering. VO2 Max training increases cellular oxygen efficiency. We need oxygen to survive. Period.