Just started WBB II. Did my first day of leg work. Holy Cow Batman !!! Those sets of 15 and 20 and 25 reps could kill ya. I was (on my first day) experimenting with the weights to see what I could do for that many reps. Even on sets where I did not get to muscle failure, I was huffing and puffing like I was going to pass out. On the squats, I had to rest (without putting the bar down) for a few seconds at about 16 reps. For those who think they're tough stuff doing 3 sets of 6-8 at heavy weights, it's nothing like doing 20 or 25 reps at a lighter weight !!! Those last reps are torture (and the set seems to last forever).
The question: Why? What is better about doing one set of 20, as opposed to two sets of 10? Is there a physiological difference? Is this just based on past experience? Is it meant to shock the system (it does)?