To get a good strength-training workout, you don’t necessarily need to push heavy weights. Or even move anything at all. And it’s all thanks to isometric exercises, or strength training moves that challenge your muscles without putting them through the normal range of motion you’d expect. (A strength-training workout where you can stay put in one place? Sign me up.)
Hold up, though. Just because you don’t move when doing isometric exercises, it doesn’t mean that they’re easy. In fact, isometric exercises will work your muscles in a different way than you’re used to—and if you do them correctly, you’ll definitely be feeling the burn.
Here’s everything you need to know about isometric exercises, how to do them, and why—and how—you should incorporate them into your strength-training routine.
What are isometric exercises?
Isometric exercises are moves whereby you contract a muscle or muscle group and hold it in the same position for the duration of the exercise, Femi Betiku, DPT, CSCS, Club Pilates instructor in New York, tells SELF. It’s different from the movement patterns you probably typically use when strength training: concentric movements (tension on a muscle that’s shortening) or eccentric movements (tension on a muscle that’s lengthening).
The easiest example of an isometric move to think about is a plank. When you hold the plank position, you’re squeezing and engaging your entire core the whole time. That muscle contraction is called an isometric contraction.
A plank is just an isometric exercise, but many exercises actually incorporate all three movement patterns.
“People forget that there’s an isometric action in almost every exercise,” Mike T. Nelson, Ph.D., CSCS, a Minnesota-based exercise physiologist, tells SELF. For example, in a squat, when you lower the weight down and your muscles lengthen, you’re in the eccentric phase. And when you push the weight back and your muscles contract, you’re in the concentric phrase. In between that, when you stop and pause at the bottom? That’s the isometric phase.
The same can apply to a biceps curl, if you add a hold to the move. When you bend your elbow and curl the weight up, that’s the concentric portion. When you straighten your elbow and lower the weight down, that’s the eccentric portion. If you paused halfway through and held the position at the top of the move, when your arm was at 90 degrees, that would be the isometric phase.
Other examples of isometric exercises include wall sits, calf raises, and hollow-body holds. Holding any of your favorite nonisometric exercises in one specific spot—usually either the most challenging part of the exercise, or the moment just before you change direction—is also a simple way to add an isometric component to whatever you’re doing. (It’s also an easy way to make an exercise feel harder when you aren’t able to add additional weight to the move.)
What are the benefits of isometric exercises?
Isometric exercises can help build strength, but in a slightly different way than concentric and eccentric movements do. With concentric and eccentric exercises, especially on the eccentric part, the muscle fiber is broken down, explains Nelson. The resulting microscopic tears in the muscle will repair after exercise—which is why giving your body time to recover is so important—and ultimately end up building themselves up a little stronger than before.
But a large portion of the strength you gain doing isometric exercises comes from training your nervous system, says Nelson. “In general with isometrics, you’re primarily training the nervous system to coordinate with your muscles in that specific position and fire the right muscles at the right time.”