Let's assume you've been having trouble with muscle pulls or strains on the bench and every time you try a personal record you can't "gut it out" because in the back of your mind you're expecting that damn pull to hit you once again. So how can you continue to train and grow in such a situation?
Or perhaps it's your knees in the Squat. Pain within the kneecaps; a kind of "grinding" at certain points within the knee when you're either maxing out or repping out. Now if you can't rep out or do max training singles or doubles . . . HOW can you continue to train and gain?
Try this for six months and see what it does for you.
For the Bench . . . change grips, sometimes going from wide to medium, or from medium to close. This may enable you to work out without re-injury . . . but how do you continue to GAIN? You can't use heavy singles or doubles because of the risk of re-injury . . . so . . . you do this:
Take a weight 90% of your limit for 2 reps and make this your working weight. Let's say you can bench 350 for 2 reps. Take 90% of 350, which is 315. Now, after a thorough warmup and safe weight jumps up to this weight do 315 for 5 singles. You progress from week to week by going from 315 for 5 singles to 315 for 10 singles. When you make that 315 for 10 singles, jump the weight up to 325 on your next heavy workout day. In a matter of a year you could be doing 400 for 5 singles, instead of "forcing" up your max in the normal fashion.
This kind of training is result producing and safe. The only drawback is that it takes TRAINING TIME . . . due to all the sets of heavy single repetitions and the rests involved between them. But if you can't max out or rep out because of the tendency for injury or re-injury, what else can you do? To put it simply, it's safer to do 350 for 10 singles than to try 400 for a single if you are injury prone.
Yet, if you can get 350 for 8-10 singles, it's almost certain that you can bench 400 x 1. So you continue on this way and maybe a year later you can get 400 for 5 or 8 singles . . . then you know you're closing in on a 450 max!
This method is also good if you train alone because it is relatively safe, because you're neither forcing reps or max poundages. Instead, you're doing many attempts at a medium-heavy weight. There's very little chance of injury. The only trouble is . . . like I said before . . . it takes time.
On the other training day, do sets of 10 reps with light weight for a pump and base the workout around assistance movements which don't aggravate the areas which tend to get injured.
For the Squat, Deszo Ban uses two methods to get around his injured knees. One day he'll use a weight he's good for one triple with, but he'll use it for singles, increasing sets of ones as time goes by. On the other squat day, he'll take a weight which he can squat 10 reps with and instead do sets of 5's. Once again he'll increase sets of 5's with this weight as time goes by. Last year he was getting 485 x 10 sets of 3's. He couldn't max out or rep out because of very painful knees but he could continue to train and gain by using this method.
So, if you're injury prone, or train alone and want a training method which will allow you to continue to train without further injury . . . and with safety . . . try this method.