Preface: this entire approach focuses on strength gains above all else. It ignores physique entirely. It’s pure Russian powerlifting training. It also thinks in terms of elite athletes, and performance.

From Pavels perspective, the percentage is relative. Meaning, if you are using weight where you reach lactic acid saturation (failure) at 8 reps, train at 75% of the rep count as a baseline. So around 5 or 6. If you are doing 6 rep max, train at 4. Etc.

Using a month as a time increment for gains, the main concept, as I understand it, is to create a difficult, and varying demand requirement for the muscles for the first two weeks of the month. Which according to Pavel, is the maximum time your endocrine system can handle those kinds of demands in a month period. Then for the rest of the month, you just do a standard 75% set, for 2 or 3 sets. The last two weeks are less intense, and are setting the weight as a new norm for your body.

Then the next month, you add 10lbs., and repeat. If your body isn’t ready for the new weight, do 5lbs, or do another month at the same weight. It’s not like you’re losing anything.
You start the next month by doing max reps. So if 8 reps is max, do 8 reps. So the first work out of the month is an ass kicker for each muscle group.  Then for the next two weeks, the variation period is varied through lifting intensity, speed of the lift (this is actually very effective) , and maybe an extra rep, or one less, changing rest periods between sets, (which again according to Pavel should be twice as long as the western norm), all done around the 75% of max reps principle.

There are lots of schools of thought about all this, but a lot of the strength guys swear by it. But the strength dudes are a different breed that the body builders.

When I did stuff like this, I would rest extra the last few days of the month, eat more, and sleep more if I could, then attack.