What and why of set/rep schemes: can someone explain?

[Chris Correia]

During the past five months, I've followed a program (Mike Mejia's Homegrown Muscle from Mens Health) that has varied exercises and set/rep schemes. Although I've read and had explained to me some of the usual "heavy weights/low reps/more strength" explanations, I'm curious about a couple of things.

The lowest rep work I've done has been on a traditional 5X5 scheme, where the weight used is my 5 or 6 rep max, and, then reps typically decrease each set after the first set or two (e.g. 5-5-4-4-3). BUT, in that scheme, I stayed with 5 reps until I could do 5 reps on all sets, before increasing weight. Why would one do that rather than increase reps on all sets all the time, until, say reps looked like 7-6-5-5-4, and then increase weight? What benefit is gained, what is the purpose? Is this a standard protocol for even lower rep work as well?

However, when doing higher rep sets, say 8 reps for 3 sets, does not one generally do their max/near max number of reps on each set, until able to do AT LEAST 8 reps on all 3 sets, resulting in, perhaps, sets of 10-9-8? (This is what I've generally done.) Why not stay with 8 reps there on all three sets, like in the 5X5 scheme?

I'm currently doing a routine where I have some 5X5 work on exercises like power cleans, where I am told to use a lighter weight, so I'm going for higher speed, and doing a full 5 reps on all 5 sets, for athletic-related purposes. Then, it has some exercises done as 4X6, which I understand are to be done like the heavier 5X5's, noted earlier.

I'm just curious about the exact why's of some of this, particularly the difference between the way reps are done across sets in the heavier work (5X5) versus the lighter work (3 X 8 or 10).

[Chris Correia]

Might it be something to do with CNS overload when working with heavier weights/lower reps? Safety?
Just a neat idea?

Might anyone have a link or two for me?

Just thought I'd try again.

[Buk]

I will try to a add few Opinions in a stream on consciousness kind of way.

Power, rest, recovery, and fatigue.

When doing power exercises such as cleans or squat jumps you are not so much working to fatigue as performance decline. This is easier to measure as a whole rather than rep by rep. Evaluate the set when you are done, and make adjustments for the next workout.

Look at your rest periods. When working at a higher intensity, I usually lengthen my rest a bit and my rep numbers are more consistent than when I am lifting sets of 10 with a shorter rest.

Why go to absolute positive failure on your 3rd set to get 6 if it will keep you from getting 5 on your 5th set? If you are lifting 7-6-5-5-4 what is your failure level for each set? I am sure that you would be able to get 5x5 with the same weight. You will push your muscles through less failure work that and that will help keep your recovery down. 5 sets to failure is a lot of stress to do every workout. Better to save a bit the first set and push it on the last set.

You want to do sets of 5 and increase the weight, don't do sets of 7, it will fatigue your muscles and keep you from hitting your target volume.

Rest so you can lift at full intensity, but don't over fatigue your muscles early in the workout, or on every set, or your recovery will hold you back next time.

[coalminer]

I will throw my 2 cents in...

I always treat higher rep sets as more speed work where I want to complete all of the sets and reps without approaching failure, I'm pretty sure if I did a true 10 rep max my workout would be shot for the rest of the day.

I can think of several reasons for sticking to 5x5 without increasing the reps. The sets you don't go to failure on are easier on your CNS, you can see if your improving from one workout to the next, and it gives you a goal to shoot for.

I don't think you should lift at or near failure all the time, too taxing.

As far as the power cleans, I think these are pretty CNS intensive, so I never go to failure and rarely do more reps than 6. Part of this though is to make sure I keep my form.

Just my thoughts...