High Intensity Cortisol Monkeys
If your training goal is to destroy your hormones, bring on adrenal fatigue, and wreck your body with high volume, high-speed low-quality movements, you should find your closest "so-called HIT class" and eat a low-calorie diet. If your goals are to build strength, increase mobility, prevent injury, improve hormone balance, build lean muscle, shift some body fat, increase energy levels, and improve your quality of life, you should start training and eating smarter than the average cortisol monkey.
On training frequency
Many of the people who come to me for a consultation or physical assessment lament being stuck in a plateau in their training. They use the the gerund "plateauing" as an action, when it is in reality a lack of action: it's going nowhere.
There are usually three causes to the lack of progress: a monotonous or unsuitable programme, undertraining and overtraining. Our role as coaches is not only to ensure programmes change often enough to continually generate adaptation, but especially to understand the individual we're coaching and manipulate frequency of training to obtain optimal results.