Training your muscles to adapt to a stressor being exercise is a balance of stimulation and recovery. Having said that it comes down to should you train to failure with a HIT type routine or do volume? I think you need both. You have to have periods where you train for strength but that leads to burn out. Then you can go to volume where it becomes a paced endurance type workout.
Lets take a body part like chest. During your power cycle you are going to failure and really pushing yourself. A work out could look like this. No warm ups are listed. Do what you need without compromising your strength for the work sets. Bench 2 x 6; incline 2 x 6 and flies 2 x 10. Those are work sets. Take you time between sets so you can give a good effort for that second set.
When you burn out training with low sets to failure then it's volume time. Bench 5 x 10, incline 5 x 10 and flies 5 x10. The only sets that should approach failure should be your forth or fifth set. Use a weight light enough so the rest time between sets is quick.
There should also be a third cycle where you train just to have fun with new exercises and machines.
The problem with high intensity workouts for an experienced trainer is burn out. If you have many years under your belt how much stronger can you get? Hit leads to burn out then to many training days will be lost.
