For the past 5 months or so, I have been pushing hard on 5 main barbell lifts, my schedule looks something like this:
Monday - SQUAT
Tuesday - OVERHEAD PRESS
Wednesday - DEADLIFT
Thursday - BENCH PRESS
Friday - ROW
I am doing 1-5 sets of 3-5 reps. It varies from week to week depending on how I feel and what I did the week before. I try to make a personal record each week for that number of sets and reps.
I am keeping up my regular full body workouts, though they are scaled back a bit. And I will skip over squats on the whole body workout, for example if I already did them for PR. I am also adding in additional glute work at the beginning and end of each workout.
I have seen GREAT gains in these last few months.
On squats I went from 65 lbs to 135 lbs for 5 sets of 5 reps.
On bench press, I went from 45 lbs to 100 lbs for 5 sets of 5 reps.
On rows, I went from 65 lbs to 100 lbs for 5 sets of 5 reps.
On overhead press, I went from 45 lbs to 70 lbs for 3 sets of 5 reps.
On deadlifts I went from 95 lbs to 165 lbs for 5 reps.
And I am still improving and hitting new PR's every session.
My point is that if you are not gaining strength, then you are leaving some change on the table. Sure it is somewhat annoying to track, but it is rewarding.
Start pushing yourself in the gym, but remember that health is the ultimate priority. Train smart but train hard.