Wina Sturgeon: A timely contraction increases strength

Adventure Sports WeeklyJuly 17, 2014 

There are three main ways to move your muscles to build or maintain strength. The techniques each have scientific sounding names: isokinetic, isometric and isotonic. There's a little known, almost secret, method of combining two of them to greatly improve the results of your resistance workout.

Despite its technical term, "isotonic" is just a more scientific name for weightlifting. The muscle being worked shortens and lengthens while moving a weight over a range of motion that also involves the movement of one or more joints (a joint is where two bones meet). The movement of the bones strengthens both the ligaments that connect the bones together and the tendons at each end of every muscle that connect the muscle to the bone.

Isokinetic exercise usually requires the use of some kind of machine or device. It provides resistance, which changes over the range of motion used in the muscle movement, and is most often done for some kind of physical rehab. This column doesn't concern isokinetic work.

Now comes the third technique; isometrics. This is where muscles contract but there's no joint movement. Pushing hard against a wall is an isometric movement. So is "making a muscle" to show off the biceps. Other examples of common isometric moves include pulling in the stomach to make the core look more fit or tightening the glutes to make the butt look more rounded. It feels like a contraction, but in fact, the muscle doesn't contract during isometrics; its length doesn't change at all.

Here's where things get interesting. There's still controversy over the effects of isometrics. Common wisdom says while isometrics may maintain strength, it's not very efficient at building it. But within the last decade, scientific studies show that in fact, isometrics actually do build strength. Further, this kind of movement is used in sports like climbing, cycling, even wrestling.

But for some strange reason, very few athletes or coaches realize the benefits of combining isotonics, or resistance, with isometrics---the 'making a muscle' kind of movement. There's an amazing increase in strength when this is added to regular weightlifting movements. But to get the full benefit, it must be done at the right time.

To understand the timing, it's important to understand the types of contractions muscles undergo during training. You may have heard the words "concentric" and "eccentric" (We're not talking about "eccentric" as in folks who are a bit odd, just muscle movement).

The concentric part of a movement is when the muscles are moving against gravity, resisting it. This shortens the muscle, which then pulls on the bone to move it. A perfect example of the concentric part of a movement is when a weight is held up near the ear in a biceps curl.

The eccentric part of that curl is when the weight is lowered, when the muscle increases in length. Eccentric contractions usually move in the direction of gravity, which is why they are harder on the muscles. Though gravity is pulling downward, the movement is being controlled. Thus the muscle and bone is moving in the direction of gravity, but at the same time, resisting gravity. An example of the eccentric part of an exercise is the flexing of the joints to lower the weight when doing a squat.

Now, lets cut to the chase. As you do your strength building exercises, there's an increased need for oxygen in the muscle fibers. The circulatory system responds by rushing blood to these oxygen-hungry muscles. That's where the desirable "pump" comes from. It's desirable because it shows that the area has been worked, and that it will adapt by getting stronger.

However, if you deliberately tighten the muscles just when the concentric contraction is about to change to the eccentric part of the movement, it forces even more blood and oxygen into the isometrically tightened muscle. Hold the static contraction for two or three seconds, tightening it as powerfully as you can. Then finish the exercise.

You'll see the effects almost immediately. You'll notice the extra strength in every athletic move you make, whether it's swinging a racquet or a bat, pedaling a bike up a hill, making a swimming stroke - even in ordinary chores like vacuuming or gardening.

Those two or three seconds of combining isometrics with resistance will pay off so well, you'll include it with every exercise in every workout you do from now on.

Wina Sturgeon is the editor of the online magazine Adventure Sports Weekly, which offers the latest training, diet and athletic information.

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