Isotonic and Isometric Exercises: Definitions and Examples

Isotonic vs Isometric!

If you are confused about the difference between Isotonic and Isometric muscle contractions, you’re not alone. Many people struggle to understand how these types of exercise are different.

To begin, let’s look at the definition of each.

Isotonic Contractions – involves muscular contraction in which the muscle remains under relatively constant tension while its length changes.

Isometric Contra

ctions – involves muscular contraction against resistance in which the length of the muscle remains the same.

In other words, Isotonic contractions are the more commonly known contractions and are what we perform every day without even thinking about it. Picking up and moving a box from one side of the room to the other is a perfect example of this type of contraction in use.

In terms of exercising, any movement where the body is lifting, pushing, and/or pulling an amount of weight is an isotonic exercise. These include bicep curls, triceps extensions, squats, lat pull-downs, chest presses, shoulder presses, leg presses, etc. Basically, every machine or free weight exercise that you perform at the gym is an Isotonic exercise.

Isometric contractions, on the other hand, are less known and not as commonly used. This type of exercise requires that whatever resistance you are using is heavy enough that you cannot lift it.

Think about trying to lift a car all by yourself. You get your hands up underneath the bumper and prepare to lift yet nothing happens. You feel your muscles firing on all cylinders and straining to lift the vehicle, but it just isn’t happening. The longer you try, the harder it gets. Your ability to inhale oxygen is forfeited as you hold your breath trying exhaustedly not to give in. Your face gets redder and your veins begin to protrude from your forehead causing you to give up from exhaustion.

A more traditional exercise-based example would be to take the heaviest dumbbell you can lift and try doing a bicep curl. Nothing happens because the resistance is too great but still your muscles are contracting under the strain. Another example would be to take a weight and hold it outstretched in front of you until your arm cannot hold it up any longer. Drop the weight into the other hand and repeat. Isometric exercises can also be done using your own body as resistance.

What are the Benefits?

Isotonic exercises offer significant health benefits. First of all, these exercises allow for greater calorie burn due to the repetition of movements and the involvement of more than one muscle working at a time.

Walking is an isotonic exercise that can greatly increase the amount of calories burned. Isotonic exercises are also better for the heart due to the increased oxygen and blood flow. The increased oxygen flow is also a reason why these exercises are safer for the general population over isometric exercises where people tend to hold their breath. Isotonic exercises are most commonly recommended because of all of the health benefits that can be derived from doing them on a regular basis.

Isometric exercises offer the ability to work muscle fibers that don’t normally get targeted during regular weight training exercises. As it tries to handle a resistance that is greater than anything you can lift on your own, your body will call upon all of the available muscle fibers to contract simultaneously in an attempt to move the resistance. This allows for all of the muscle fibers to become fatigued. These contractions are considered to be better for toning and sculpting the muscles. Isometric exercises also take less time to perform which is helpful for people on tight schedules.

As stated earlier, these types of exercises can be very dangerous, especially for people with heart disease and high blood pressure due to the limitations on oxygen consumption and blood pressure build-up caused by the immense strain placed on the body. Practice these types of exercises and contractions only with permission from your doctor.

Bottom Line

When choosing between Isotonic and Isometric exercises, be sure to look at your own goals before making a decision. Are you looking to lose weight, burn calories and build lean muscle? If so, then Isotonic exercises are the right choice for you.

Are you looking to sculpt and fatigue your muscles like a bodybuilder? If yes, than Isometric exercises are more than likely what you need. If you are feeling ambitious, both types of exercises can be included into your routine effectively as well. Each type of exercise has its benefits, risks and rewards, so choose accordingly.

Sources

Animal-Kingdom-Workouts.com (2010, December 27). Understanding Isometric-Isotonic Contractions. Retrieved from https://www.animal-kingdom-workouts.com/isometric-isotonic.html

TheFreeDictionary.com (2010, December 27). Isometric-Isotonic Definitions. Retrieved from https://www.thefreedictionary.com/isometric; https://www.thefreedictionary.com/isotonic