Do triathletes need to do "cardio strength" training.

I think they are all effective including P90x and Tabata, crossfit, Insanity,etc.. Really it comes down to goals, age,weight,time of year, time available to train.

I do heavy workouts because that's how I like to lift, but the extra muscle does not help my race speed on the run.  It also slows me down on bike climbs.  I am a faster swimmer...but I don't know where the threshold is for gaining speed vs the weight I lift.  I could probably get the same gains at 2/3 the weight I move in my arm, back and shoulder routines.

I like to increase and improve in everything I do.  So when I lift, i end up pushing the limits.

The biggest advantage I find from the weight training is in the diminished frequency of injuries.  I rarely hurt myself ...outside the old, serious injuries of the past which I have to manage carefully.

I think cycling through different kinds of training for different times of year is appropriate.  Right now in the dead of the off season I lift heavy Olympic type stuff.  Heavy deads, heavy bench, Clean and press, etc.  I like to move my max weight and power out.  The month to month and a half prior to my first race I'll move in to the 10-15 rep range and once the season starts I'll keep weight workouts in a crossfit style.  I'm of the opinion with how flawed studies tend to be on this it's better to just keep yourself as well rounded developmentally as possible. 

Those types of workouts have actually been around for a while, but the names change. Crossfit, of course, is fairly new and while those activities were adopted by a select few, it's going mainstream now. I mix up my weight training now (I used to only life heavy before I started triathlon). I've found that the "cardio strength" training can work wonders pushing my anaerobic threshold when I let it. What I like about it also is that since I've been lifting for so long I probably have a lower chance of injury pushing AT doing weights then I do sbr.  I'll still do some sbr, but I think some of the benefits will transfer over.