Strength training is the practice of lifting progressively heavier weights. This progression forces an adaptation and teaches the muscles to contract harder under more intense loads. It may sound counterintuitive at first, but it is possible to gain strength with a weight so heavy that you can’t even lift it. This style of training is called isometric holds, static contraction training, or isometric exercise.
So, what are Isometric Holds?
If you went to the wall of your house right now, placed your palms on it, and pushed against it for ten seconds, as hard as you could, driving with your legs and arms, your muscles would contract and you would feel like you had been lifting. Of course, the house wouldn’t move. An observer would not see a rep being performed. They would see an isometric hold.
Bruce Lee, the martial arts superstar, attributed much of his physique and leanness to the strategic strain of isometric holds. In his book The Art of Expressing the Human Body he said that he would sneak them in whenever he could. While stopped at red lights, he would push against the roof of his automobile as hard as possible for as long as the light stayed red. He would also build isometrics into his workouts. If Bruce Lee swore by something, it’s probably worth looking into.
How Isometric Holds Work
If you can bench press 225 pounds as a max effort, then you could hold substantially more at the top of the bench press position. Imagine that you can actually support 350 pounds. Just by holding it for 10 seconds, you would strengthen your tendons and elicit a muscle building response because you are still forcing muscle contractions. This sort of isometric hold forces you to put maximal effort into the weight, because if you did not, it would fall. For this reason, sets of isometrics (when the weight is supported overhead or over your chest) should rarely last longer than 10 seconds, just to make sure that you stay safe – also use a spotter.
Perhaps you can’t do a pullup with 100 extra pounds strapped to yourself, but you could perform the bottom three inches of the movement. If you pulled yourself up three inches and held that position for as long as you could, your biceps and back would still contract and grow, provided that the stimulus was intense enough.
There are elite squatters who say that, before they could even attempt a squat with 500 pounds, they would still load that weight onto their backs and practice standing, walking it out of the rack, and supporting it. Their stabilizing muscles would quiver, but they were teaching their bodies that they could handle the load while strengthening their musculatures in the process. When it was finally time to attempt full squats with that poundage, they were better prepared for the shock by the practice of those earlier static contraction sets.
Isometric holds aren’t simply beneficial for strength training and muscle building. Sometimes nagging injuries and minor tweaks can prevent a lifter from performing movements with a full range of motion. Simply supporting a heavy load at a particular, pain-free spot in the movement allows you to benefit from a variation or semblance of the movement without experiencing pain that would delay rehabilitation of the pertinent muscles and joints.
Isometric Holds without Weight
You shouldn’t get the idea that isometrics only work with weighted exercises. If you’ve ever done a plank — where you hold a pushup position at any desired point in the movement for as long as you can to strengthen your core — then you’ve done an isometric exercise. Simply hanging from a pull-up bar at various points counts as well. Getting into a sitting position against a wall and holding it (a “wall sit”) is yet another example. Any position you put your body in that causes a muscular contraction falls under the realm of static contraction training.
Any movement that can be loaded with resistance – whether the resistance comes from added weight or simply by gravity pulling on your body – can be performed as an isometric hold. Think of it as pushing against the earth. You won’t get the earth to move, but you can make incredible gains by trying. Smart training is about continually expanding your toolbox of options. Isometric holds are a very easy experiment to run and will be a valuable addition to your training methods.