Here was an interesting article from the sometimes good, sometimes bad T-Nation earlier this week that I enjoyed.
http://www.t-nation.com/free_online_article/most_recent/unilateral_movements_make_you_weak
Arguing that the Split squat is a single leg exercise is and always has been rubbish, but also his argument is pretty absolutist in comparing pistols etc versus barbell squats.
why is it rubbish? it's unilateral in the sense that only one leg is performing hip extension.. so even though there's two legs "on something" (one on ground, one on bench), they both have very different roles, the majority of movement comes from one limb.. i see your point though.. and ya, unilaterals/stepups would be considered far more unilateral.. weighted pistols etc, i'm not a fan.
I would also argue that getting strong on certain single leg exercises such as step ups and walking lunges (especially UPHILL walking lunges - but that does require a hill and the ability to carry your really heavy shit to a hill, and in some cases, a portable pair of squat stands to get some decent weight to walk up hill with onto the bar - unless you ar ehappe to clean it off the ground...but I digress) are extremely beneficial for running and jumping athletes, who were admittedly not really mentioned in the article.
it's a powerlifter/olylifter/bodybuilding vibe article, so, from a performance standpoint it does a disservice. Getting strong on bilateral movements is very important for athletes, you can recruit far more mass in each rep, cause significantly more fatigue/supercompensation, etc. Because the weight can be so much more (eventually), it really helps you tap more into the 'innate reserves', or the potential motor activity that is hidden/protected except in the most life threatening cases.. You can't achieve that using weighted pistols. You can achieve it to a point on unilaterals, but heavy bilateral training is far more effective, and shock/real plyos/BIG ADA can even be more effective.
You don't get scared/elevated HR/super aroused mentally before doing pistols, you do however achieve that before unilateral lunges, and even more so before heavy squatting.. that is a VERY important factor regarding tapping into protected motor potential.
Also, I have had back trouble recently and have not been able to squat or deadlift (ironically I was installing a new, very expensive, power rack into my gym when I injured myself - I haven't squatted on it at all ) and have been doing nothing but dumbell lunges and weighted step ups for about 6 weeks now. It will be interestign to see how much my squat has dropped off when I get back to it (and I am expecting a drop off - ass the author of the article noted - for weighted exercises the transfer doesn't necessarily go the other way).
damn that sucks man..
it'll still have transfer.. regardless, if you gain strength/mass unilaterally, it will transfer, it's just that squat/lunge is such a different movement that of course it won't transfer perfectly, that's why the article bugs me, of course you're going to have to re-learn the squat a bit, but of course it will transfer... For example, if you weren't hurt, and focused on doing some massive unilaterals, barbell walking lunge, barbell bss, barbell stepup, and you did this for 12 weeks, comparing a pre-test squat 1RM vs post-test, there'd be no doubt that post-test squat would be way higher.
But overall the article is ok.
peace man, thanks for teh post!