What kind of weight training are you doing?
I mean, do you do total body workouts like MIS al the time? Do you do split workouts where you work chest and back one day, shoulders, tris and bis another? Or are you training just one body part per day?
If you have been doing total body workouts for the last 7 months, maybe you need the change of doing the split training? It might help you to break past this plateau by working fewer body parts per day but with greater intensity. One reason is that other muscle groups always come into play no matter what the muscle group we are currently targetting, therefore pre-fatiguing the other muscle groups before you have a chance to realy work them. If the muscle groups are already pre-fatigued, this can limit the total amount of weight you will then be able to lift.
For example, when you work the chest, which Cathe often places ahead of shoulders in her workouts, you are also calling upon the shoulder muscles. I often find that after doing chest, by the time I get to shoulders, those mucles are already so tired that they cannot be challenged by my attempts to lift heavier on shulder exercises that day.
So, trying split training can help.
Also, in light of the above discussion, if you have DVD's it is easy to change your training in another way to help get past a plateau. Change the order in which you do the exercises. So, if chest always comes before shoulders, and you have tried and failed to increase the poundage for shoulders exercises, then today, do shoulders first and see if you can select a heavier weight and complete the reps with that.
Increasing weights is something that has to happen slowly. For example, say you target shoulders first. Cathe will typically include 3 or 4 exercises to target the shoulder area. Now, you may find it impossible to increase the poundage for all of the shoulder exercises at the same time. I do. So, select 1 or 2 exercises, say military/overhead preses and lateral/side raises, and make those the exercises where you lift heavier today. Then for the remaining shoulder exercises, lift the amount you usually do. Over the following few weeks, you can play aaround with this and gradually include more exercises per session in which you up the weight until you find you are liffting heavier on all shoulder exercises.
Also, you have to be prepared to stay in trasition phase for a while ansd not inteerpret it as "failure." What I mean is, say you decide to lift heavier on biceps today and you pick up the 12 pounders insstead of your usual 10 pounders. Great! Start the first set and do as many reps as you can, with good form, at the higher weight. You may be able to complete the set, you may not. If you cannot, you do not worry, all you do is immediately drop the weight to the 10 pounders and complete the set at that lower weight. The next workout, you strive tocomplete more of the reps at the higher weight until you have to drop down, until you reach the point where you can complete all the reps of that set at 12 pounders and you start the secomnd set on the higher poundage too!
Remember, when you aare striving toi conquer a heavier weight, the muscle will reach failure at some point, but that doesn't mean "you" have "failed!" Quite the contrary! It means you are making good progress!
Another thing you can do is try out the Slow & Heavy series which is the "perfect series to break through any and all strength training plateaus" to quote Cathe from the introduction. In this series Cathe performs slow reps with the heaviest weight posible, and the slow count takes all the momentum ouit of the lift. THe only thing lifting that weight is you, your muscle. During a 3-4-5 week rotation of this you can definitely increase your weights.
I have nearly completed a 5 week rotation of S&H and I am now lifting the heaviest eights I have ever lifted in my life. I have increased the poundage on chest, back, shoulders and triceps! I am very pleased!
Hope some of these suggestions help!
Clare