Resistance Training: Isometrics

This is the last of the resistance methods we're going to talk about, and there's a good chance you've heard of it before. There's also a good chance you don't really know what it is, since the term "isometrics" gets used incorrectly a lot.

Go back to our arm curl example again. First we used a dumbbell for resistance, then our other hand and arm, then our imagination (with a little help from the tricep on the same arm). But they all had this in common: We moved our arm through a range of motion.

Isometrics have no movement. An isometric curl would hold the arm in one position while the muscles tightened. The classic isometric exercise involves standing in a doorway, placing a hand on each side of the opening, and pushing Samson-style in an effort to shove the door jambs apart. Of course, if the house hasn't been condemned, the doorway shouldn't change its shape at all; you'll just stand there, motionless, your whole body shaking with the effort of not being able to move at all.

Isometrics can give you incredible results. There are stories of early twentieth-century strongmen who trained using isometrics exclusively. But there are some caveats to this method:

• Because there is no motion, isometrics only build strength at the position in which you exert your effort. If you want to use them to build overall strength, you need to do them with the muscle in three or four positions. Using the curl example, you might do an isometric with the arm barely curled above your leg, then at the midway point, then with your forearm almost touching your bicep.
• It's easy to "crunch" your muscles if you try too hard, or even pop a blood vessel. That may be the biggest danger to this method. If you overdo it, you can end up with painfully cramped muscles or worse. Despite the possible benefits from this kind of training, I don't do isometrics very much for this very reason.

So there you have it. That's 5 different types of resistance training you can mix and match in your workout program. Over the next few days we'll look at some popular methods of blending them.