Another morning, another day at the gym. You feel fresher, and there is more clarity – maybe it is the caffeine. You notice, hear, and see everything which you wouldn’t normally.
Over your left, you hear a buffed guy grunt. You turn and see him curling those biceps (isotonic). While you get over your elliptical, you see on the other corner, a woman holding a still plank position (isometric).
You ask yourself, is that even worth doing? Is weight-lifting better than holding a still position?
Well, it depends. Let’s discuss how one is better over the other with some examples.
But first, let’s the describe isotonic and isometric exercises and know the difference between a can of coke.
Isotonic Exercises are the everyday workouts you do at the gym which involves a range of motion. It involves your muscles contracting – either shortening or lengthening.
Isotonic comes from the Greek “iso-“, equal + “tonos”, tone = maintaining equal (muscle) tone.
Isometric Exercises are strength exercises where your muscles contract while you hold a still position.
Isometric comes from the Greek “iso-“, equal + “metron”, measure = maintaining the same measure, dimension or length.
Isometric vs Isotonic Difference
Let’s try with a can of soda
The guy you saw at the gym earlier doing a bicep curl was an example of an isotonic exercise. Grab a can of soda or something with little weight, and you can do one now.
Concentric Muscle Contraction
Hold the can nice and firm. Keep it on your side, and while you keep your elbow joints still, lift the can up.
While it comes up, your muscles contract and shorten. As your pulling force is more than the resistance of the can, it is concentric muscle contraction.
Eccentric Muscle Contraction
Now slowly release the tension and let your arm come back to the initial position. As your forearm lowers, the resistance of the can is more than the energy you put in. Therefore, the muscle lengthens, but still contracts – it is eccentric muscle contraction.
If you release the tension altogether, your hand can snap back and injure you. (Not in the case of a can, of course). If you get a dumbbell, you need to release the tension slowly, which still uses your muscles to contract, while they lengthen.
Isometric Muscle Contraction
Hold the can midway in a still position, nor curling or moving. The muscles are still contracting but they don’t change the length.
You have kept the weight of the can and the force at the same level. Easy enough? Ask that girl at the gym you saw earlier, how much tension did she feel in her core while holding a plank?
Both isotonic and isometric exercises are performed to build strength, and each has their own advantages. Let’s dive into them.
Isometric vs Isotonic; Benefits
Other than building strength, all have their own advantages.
Your most workouts will be isotonic if you go to the gym.
If you do yoga, you would do little more isometric exercises.
If you are into calisthenics, most of your workouts will be based around isometric exercise, where you would need to hold positions for little longer.
- One can attain maximum muscle contraction
- Improve bone density
- Improve cholesterol level
- Improve digestion
- Maintain muscle tone and shape
- Recovery and rehabilitation
- More range of workouts
- Relatively cheaper
- More blood is pumped which increases muscular endurance
- All major muscle groups can be exercised
- Needs fewer repetitions
- Build strength on the full range of motion
Bravo! But how does it help me identify which ones should I do?
Well, let’s look at some examples and compare similar workouts done in isotonic and isometric capacity.
Top 5 Isometric vs Isotonic Examples
We found the best isotonic and isometric exercises which are similar to one another, so you can relate which one works for you better.
For isometric exercises, do as many reps required by your workout plan. For isotonic exercises, hold your position while in contraction, for as your workout plan requires.
For Isotonic exercise, you can open your leg wide, tip the floor with your toe, and then bring it back to original position. Repeat for the other leg.
For isometric exercise, you can hold a position on your toes and forearms, keeping your back straight.
Muscle worked: abdominals, quadriceps, and the anterior portion of the deltoid
For isotonic exercise, stand straight, and bend your knees till your hips level your knees while keeping shoulders aligned with your feet.
For isometric exercise, stay low for as long as you can with your knees bent, and shoulder aligned with your feet.
Muscle worked: quadriceps, gluteus maximus, hamstring, abdominals, obliques
3. Overhead hold
For isotonic exercise, take the dumbbells, take them over your head keeping the hands straight, and bringing them back down at your head level.
For isometric exercise, take the dumbbells, and hold them over your head.
Muscles worked: anterior, posterior, and superior portions of the shoulder.
4. Glute Bridge
For isotonic exercise, lie on your back, bend your knees with feet on the ground. Lift your glutes aligning your core with your knees.
For isometric exercise, keep the same position with glutes raised aligning them to your knees.
Muscles worked: hamstrings, glutes
For isotonic exercise, lie down facing the floor, and lift your hands and legs high.
For isometric exercise, hold your hand and legs as high as you can.
Muscle worked: gluteus maximus, Hamstrings, erector spinae
Isometric vs Isotonic: What is Better for you?
Combination of both is ideal for any workout plan.
If an isotonic workout has an isometric sister then you should mix both and see which ones give you more burn.
The woman holding a plank position by no means is an easy workout. Planks holds are known more their difficulty.
Identify the benefits mentioned above, and try to mix things up for all-around benefits.
Frequently Asked Questions
Isotonic: Muscle change in length without an increase in tension
Isometric: Muscle does not change in length
Isotonic: The muscle maintains at the same tension while it shortens
Isometric: Strength training in which muscle length and the joint angle do not change
This is when the tension remains the same while the length of the muscle changes
Bicep curl is a isotonic exercise as the muscle in contracting and expanding through the motion
Since the muscle in your arms are contracting and expanding, this is also am isotonic exercise.
Isotonic exercises help increase bone stress, overall energy and promotes weight loss
Since there is contraction involved, jogging is considered an isotonic exercise.