One of my favorite proverbs goes such "A chain is only as strong as it's weakest link."
We've all heard it before. You can have the strongest pieces of metal holding that chain together, but one little weak piece will cause it to snap in two when push comes to shove.
And the same applies to your body as well. You can have the strongest arms and legs in the world, but weak lower back muscles will always limit the amount you can push and pull. You can have huge biceps, but weak forearms will always limit your gripping/pulling potential. Strong quads coupled with weak hamstrings are an open invitation to injury, especially if your an athlete. And the list goes on and on.
So, what can YOU do to ensure that you strengthen all your weak links?
Well, for one,you can base your workout upon compound exercises that work several groups of muscles together as opposed to exercises that claim to "isolate" certain muscles. This means, that for example, you concentrate on getting better at doing pull-ups in good form rather than sitting on a chair and pumping out curls to "develop the peak of the biceps muscle". Remember that exercises that work several large muscle groups together are the BEST exercises you can do - not just for overall development, but also to ensure that any weak links in the chain are quickly identified and fixed. Try doing pull-ups with a weak grip - it just won't work unless you strengthen your grip.
Second, you need to make sure you actively strengthen your weak links instead of ignoring them. So in the example above, avoiding the pull-up in favor of the lat pulldown machine is NOT the answer. Work the exercise until you have a solid grip - and work your grip in particular as well - in other words, ensure you strengthen the weak link to the fullest extent possible.
Remember, a weak link means you have a problem. And when you have a problem you don't ignore it and hope it'll go away on its own. You must actively FIX that problem - and the very same thing applies to weak (or underdeveloped) parts of your body as well.
By the way, this little gem of a saying doesn't just apply to fitness - this applies to business, daily life, security, and just about anything else you can think of. Think of a Ferrari with a powerful engine but a suspension that is about to fall apart. You get the point. . .insert example of choice, but the fact remains that weak links are there to be fixed - not ignored.
Do so, and you'll notice a vast improvement in your overall strength and fitness levels within a few days.
PS: - The best compound exercises can be done with little other than your own bodyweight. That's right - you don't need a single weight to get in a decent workout. Check out Fast and Furious Fitness for some GREAT compound exercises that YOU can include into your routine today!