Type 1:HIIT (High-intensity interval training): has a very high calorie burn per minute and benefit of EPOC (excess post-exercise oxygen consumption) but is very fatiguing and has a higher risk of injury.
An example is 20:10 sec work/rest airbike
Type 2: MISS (Moderate intensity steady state) has a moderate calorie burn and is great for cardiovascular fitness but interferes with muscle gain and adds fatigue.
An example is our Wednesday and Friday session (60:30 work rest)
Type 3: LISS (Low-Intensity Steady state) Adds little fatigued and has a low chance of injury however also a low calorie burn per minute
An example is a 10km jog
So the question of what is best?
At Big 5 we tend to use HIIT during finishers for the benefit of high calories and EPOC and to balance out the extra fatigue we emphasize the importance of proper recovery and rest. For total training outside of our sessions and for anyone doing their own thing, try to include a mixture of all three. HIIT works really well when done at the end of your normal weight session around 3 times a week, We include MISS once a week in its own 45 min session. LISS is something that can be done as more of a recovery once a week.
Ps: Thanks Renaissance Periodization for the pic