I'm sensing a groundswell in the fitness world...sort of like one of those "great disturbances in the force" that Jedis get from time to time.  Mike Boyle sent out a piece he wrote on circuit training today; this afternoon I got a review request for a book called "Hardcore Circuit Training For Men" (I'm somewhat wary of the term "hardcore" and "for men" in the same title, but I'll reserve judgment). 

Anyway:  circuit training isn't new, of course.  As Boyle notes, it was making the rounds fifty or sixty years ago.  But ever since I took up strength training, I've wondered about these huge pauses we're supposed to take between sets.  Some protocols call for 3-5 minutes between sets--meaning you squeeze in just fifteen sets in an hour of lifiting! 

It isn't that I doubt the concepts behind these lifting systems--it's that they seem...boring.  I know they're not boring if you like to load up the Olympic bar with enough weight to bend it and slam out three nose-bleeding reps at a time, but, due respect, that's not my speed, and it's not the speed of most people I train. 

Now--Eric Cressey posed an pointed question in a recent TMuscle piece on squatting:  "Is any exercise truly functional?" he asked.  Meaning, life is life, sport is sport, and exercises are exercises.  If it's an exercise, by definition, it's not really sport:  it's a variation on a theme, but it's not the sport itself. 

The same could be said of exercise in general.  Everyone can argue for the "functionality" of his or her training program; it just depends on which particular function you are trying to refine.  Big LIfter Man could say he wants to be able to move refrigerators by himself.  Long Distance Runner Man could say he wants to be able to get from point A in Indiana to point B in Idaho without the aid of a motor vehicle.  And both of them could make an aesthetic argument for the merits of the particular type of physique their activity builds. 

Personally I want to get better at working intensely over an extended period of time.  I want to be a guy who can move furniture for a few hours and not crap out after 20 minutes.  Or play an afternoon rough-and-tumble game with my kids and not worry about them outlasting me.  Or--in my latest passion--get through an aikido class without fatigue interfering with the workout. 

For these purposes, a kind of circuit training serves me well, and that's what I'm practicing at the moment. 

My feeling is that when sprints were "discovered" a few years ago, people realized that there was a whole new level of fatigue and exhaustion one could generate by working the whole body at maximum intensity for brief intervals, and that that kind of full-body blitz was missing, for all intents and purposes, from the average person's steady diet of isolation exercises and low-intensity cardio training.  Nowadays, whether they settle on sprints, circuit training, or another form of intense training, 'hardcore' types are seeking that same kind of thorough workout--something that makes them feel wrung-out in the short term, but very quickly, alert and energized. 

I admit that I have a bias in this--it works for me and it's worked for clients--but given what most people are seeking in the gym--not "I want to be huge" or "I want to lift Volkswagens" or "I want to run to Miami" but "I want to be lean, strong, and athletic, and have boundless energy"--I'd say circuits are a pretty darn good fit.