For anyone interested this is the article:
http://gubernatrix.co.uk/2010/08/does-lifting-more-always-mean-you-get-stronger/
(it's someone on here's friend's site I think)
I've read about this previously, but I can't remember where. To sum up for the lazy
, it's about training at the best % of 1RM weights for optimal strength progression. This is around 70% to 80%. Before anyone gets excited, this probably will not apply to training with these weights for high reps or to failure. This is about sub maximal loads.
Reading it reminded me of a guy I got chatting to in the gym a couple of months ago. I was sharing a bench with him and gave him some help with his form (and also his friend who was just starting out, which was fairly lucky as the "more experienced" guy was begining to get pains in his shoulder...). I tried several things with him to help him get things firing properly, including dropping the weight down considerably. I think he was doing 90kg for 3-4, and I dropped him down to 60 or 70kg. He said that he'd been stuck at just under 100kg for a while now, so I suggested that he reduce the weights and gradually ramp them up over the next few weeks using sensible rep ranges and making sure his form was spot on. Of course, he decided that he would just keep hammering away at 90kg.
Not to say the it's the only, or even the best, way to gain strength, but 5x5 type training with progressive sub maximal loads is fanstastic. My powerlifting routine works similarly, with the majority of the strength being built around the 6x5, 6x6, 5x5, and 4x4 sessions.
Benny, whether you do 5x5 or 5x3 will be mostly dependant on how much you're doing on the day. The higher volume obviously suits A/B day splits with fewer exercises per day. To make things more complicated, you *could* do a pyramided 5x5, but I wouldn't bother.