Changing into workout clothes and breaking a sweat isn’t always an option when you’re strapped for time or at work. Isometric exercises, a.k.a. “static contraction training,” could provide an occasional alternative with benefits you can’t get from traditional workouts.
By definition, isometrics refers to exercises in which there is no change in the length of the muscle, says Irv Rubenstein, exercise physiologist and founder of S.T.E.P.S., a science-based exercise facility in Nashville, Tenn.
“More accurately, it’s when the joint doesn’t change angle so the muscle length stays the same. Many of the movements we make and positions we assume in life are isometric.” Examples include sitting or standing in good posture; even picking up a box is isometric for the back, although it requires lengthening of muscles of the legs, Rubenstein adds.
In addition, many traditional, or “isotonic exercises” (exercises that involve a stretching and contracting of the muscle) also contain an isometric element. At the gym, for example, bench pressing requires an isometric contraction of core muscles. You also isometrically contract your core during squats to keep your back stable when using heavy weights — less so for bodyweight squats. Exercise machines, on the other hand, stabilize your body for you and therefore do not require isometric core contraction.
Here are some of the pros and cons of isometrics along with a few popular examples to try on your own:
The Benefits of Isometrics
Convenience You can do isometrics anytime, anywhere, says Rubenstein. “Even in the car or on an airplane. They’re effective for tone and muscular strength, although they’re not as effective if you’re mainly looking for endurance improvements,” he notes.
An isometric abdominal exercise includes simply contracting your abdominals and focusing on pulling in your belly button towards your spine; hold a few seconds and release.
Less joint stress Isometrics work well if you have achy joints. “Since the joints don’t move, there’s less stress on them,” says Rubenstein. Simply gripping underneath a desk or sink works the biceps and can be done without hurting the elbow joint, for example.
You can often do isometrics if you’re injured Many isometric exercises can be done even when you’re recovering from an injury, and they are often prescribed as part of a rehab program. “If you’re immobilized and can’t move, they’re better than nothing,” says Dr. Bert Mandelbaum, orthopedic surgeon at Santa Monica Orthopaedic & Sports Medicine Group in Santa Monica, Calif. “If you’re not injured, however, isometrics should be a part of a bigger program that includes isotonic exercise as well.”
The Downsides of Isometrics
May increase blood pressure Isometrics themselves don’t increase blood pressure, but holding your breath while performing them, a practice called the Valsalva maneuver, can. “This is usually only an issue with large body movements,” says Rubenstein. Smaller isometric exercises for your arms, for example, are less likely to have this effect. In fact, a study by the American Heart Association showed that four weeks of isometric handgrip exercises produced a 10 percent drop in blood pressure.
Many isometric exercises can be done even when you’re recovering from an injury, and they are often prescribed as part of a rehab program.
You don’t burn many calories Since you’re not moving, you’re not expending that much energy, says Pete McCall, senior adviser for the American Council on Exercise (ACE). “You’re doing a much smaller amount of work than you would when doing isotonic exercise or cardio. You get more bang for your buck doing other things.” Include cardio and traditional exercises along with isometric moves if your goals include weight loss.
Isometrics are not complete on their own Isometrics can be part of the overall fitness picture, but their role is limited in the general scheme of things, says Mandelbaum, who recommends using isometrics only in a pinch or as a small part of a traditional workout regimen.
General Guidelines for Isometrics
- Avoid holding your breath, which raises blood pressure
- Hold each contraction for three to 10 seconds (based on your abilities)
- Modify the exercise if necessary
Do these three moves — described below — on their own or include the planks and dead bug as part of your core workout and the wall sit along with your leg exercises.
Get in position on your forearms and up on your toes; make sure to keep your back straight — avoid hiking up your hips or allowing your back to sag; hold for 20+ seconds. For a greater challenge, raise one foot off the ground a couple of inches; hold and repeat with the other leg.
Lie on your back with your knees bent and feet flat on the floor. Engage your abdominals by pulling your belly button in towards your spine. Lift both arms and legs off the floor; knees should directly over hips and bent at a 90-degree angle; elbows should be directly over shoulder joints so hands are behind you. Slowly lower the right heel and left hand toward the floor. The hand and heel should tap the floor lightly (but not rest). Then slowly bring the leg and arm back. Continue the movement, alternating sides.
Stand with your back against a wall and lower yourself until your upper legs are parallel to the floor. Shuffle your feet forward until your lower legs are parallel to the wall behind you. Your knees should be bent to 90 degrees. Hold your arms out in front of you and hold the position for 10 to 30 seconds.