On one hand, HIIT is quick to perform and may be more interesting for certain people, but on the other hand, it also requires more recovery and may interfere more with weight training. There is a physiological similarity which supports that doing too much HIIT may be wasteful. It is advisable to maintain a ceiling of 1-2 HIIT sessions per week and to deploy them as a last resort especially if it’s your favoured form of cardio.