Well, there is a way to work your muscles effectively with no equipment at all, even while you’re busy taking care of other business at the same time. If you’ve got 10 seconds you can spare, you can squeeze in one exercise. And over the course of a day, you can get in a full body workout without interrupting your busy schedule.
This muscle training method is called isometrics, or isometric exercise. As you’ll soon find out, it’s not a complete substitute for more traditional forms of strength training, and for some people with specific medical concerns it may not be appropriate at all. But it could be just what you need when you can’t do your regular routine, or when you want to give your training a little boost by adding an additional element.
What Is Isometrics?
Isometric exercise is your body’s answer to the question, "What happens when an irresistible force meets an immovable object?” The answer is that your muscles will get stronger without actually moving. If you’ve been doing your homework and reading up on strength training, then you already know that your muscles gain strength when you challenge them to produce more force than they're used to. This is typically done by forcing them to move against resistance or weight, like when you do a bicep curl while holding a dumbbell. As you gradually increase the weight or resistance, the muscle responds by getting stronger.
But muscles don’t actually have to move this added weight in order to get stronger. If the resistance is so high that they can’t make it move, they can still get stronger just by trying. There are three ways a muscle can contract to produce force (and eventually build strength):
- A concentric contraction occurs when a muscle is contracting while getting shorter. This is the contraction your biceps do, for example, when lifting a dumbbell up during a bicep curl.
- An eccentric contraction occurs when a muscle is contracting while getting longer. This is the contraction your biceps do, for example, when lowering a dumbbell back down during a bicep curl.
- An isometric contraction occurs when a muscle contracts without changing its length or causing any movement of the bones to which it is attached. The best example of this is pushing against a wall, or pulling up on a window that is stuck. This is the contraction your biceps do, for example, if you were to pause anywhere along the lifting or lowering phase of a bicep curl—your muscles are working without shortening or lengthening.
Why Include Isometrics?
There are several very good reasons to include isometric contractions in your strength training program. For one thing, real life situations often require the ability to hold yourself in a certain position—carrying several bags of groceries, squatting down to scrub a floor, holding a baby in your arms—and isometrics is a good way to train your muscles to get better at handling those specific positions. For another, isometric training usually involves exerting maximum force, which will activate and train all of the available muscle fibers and lead to more significant improvements in strength in less time.
But perhaps the most significant benefit for many people is that isometric training can literally be done anywhere, without any special equipment at all. All you need is about 10 seconds to do a single, effective isometric exercise, and you can probably do it without anyone noticing you’re actually exercising.
Let’s say, for example, that your day is just too busy for you to break out the dumbbells and do several sets of bicep curls. If you can find 10 seconds, a couple of times during the day, to press your palms together as hard as you can, you can still exercise your arm muscles effectively. If you can sit in a chair with your abs engaged (tightened) and your feet held just slightly off the floor, you’re giving those core muscles a good workout. If that’s too easy for you, just push down on your knees with your hands while trying not to let your feet touch the floor. To work those upper back and neck muscles, clasp your hands behind your neck, elbows wide, and push your head back while trying to push it forward with your hands. With a little creativity, you can think of ways to use one muscle or limb to oppose the opposite one (or find some immovable object in your environment to push or pull against), so that you can give most of your muscles a good isometric workout. As long you exert as much force as you can for at least 10 seconds for each exercise, you’ll get the training benefit.
The Limits of Isometrics
The biggest limitation of isometric exercise is that each isometric hold only increases your muscle’s strength in that exact position—not through a full range of motion. In other words, if all you do to strengthen your arms is press your palms together with your elbows bent at right angles, you’re arms won't become stronger at lifting things when your elbows are straight (or at any other angles). Therefore, it's impractical to make isometrics your primary form of strength training—you’d need to do many exercises, each at a different joint angle, in order to strengthen a muscle at all points in its full range of motion. Talk about time-consuming!
Isometric contractions also restrict blood flow and can cause sharp rises in blood pressure during the exercise. This means that isometric exercises can be unsafe for anyone with heart disease or high blood pressure, and women who are pregnant. If you fall into one of these categories, do not try isometric exercises without the consent of your doctor. If you experience any unusual symptoms (headache, nausea or dizziness) while doing isometric exercises, stop immediately and don’t use isometric exercise without clearance from your doctor.
For everyone, it is very important to remember to breathe properly during any intense muscular contraction, especially the maximum contractions of isometric exercise. Never hold your breath during the contraction, and try to maintain a normal breathing rhythm. And avoid extending the time of maximum muscle contraction much beyond 10 seconds.
Adding Isometrics to Your Program
Supplementing your concentric and eccentric strength training exercises with some isometric exercises is ideal. In addition to using isometrics when you don't have time to do anything else, as described earlier, you can also add them into your regular routine, to make sure you’re really working your muscles to the point of maximum overload.
There are many ways to do this. For example, you can easily turn a regular exercise into an isometric one by simply pausing and holding, somewhere along the range of movement, for a few seconds. In general, it will be harder and result in greater benefit when you hold closer to the very top of the lifting phase or the very bottom of the lowering phase (without actually getting there).
Here are a few examples:
- When doing bicep curls, tricep extensions, chest presses and similar resistance exercises, pause halfway through your lifting (concentric) phase and hold the weight steady. Make it harder by pausing just before you lower back down to the starting point of the exercise.
- When doing squats, lunges, and pushups, pause after lowing yourself down (at the end of your concentric contraction) and hold your body steady.
- When doing crunches, pause at the top of your crunch and hold. Make it harder by pausing just before you reach the starting point of the exercise (shoulder blades just hovering above the floor).
It's also good to vary the holding point from workout to workout in order to maintain strength through the whole range of motion.
You can also use isometrics to involve additional muscles in some regular exercises too. For example, if you’re doing a plank exercise to strengthen your core muscles, try adding a few isometrics to engage your upper body. Instead of keeping your elbows straight and locked, bend them just slightly and try to hold that position. That will give your arm and shoulder muscles something to do, along with your core muscles.
These SparkPeople Exercise Demos combine lower body isometrics with upper body exercises:
Now that you know all about isometrics, get out there and do your best to NOT move a muscle!