Isotonic and Isometric Exercises: The Differences and Benefits

Isotonic and isometric exercises are two complementary forms of muscle strength training. Here, we'll talk about their different benefits and give some examples of beneficial exercises.
Isotonic and Isometric Exercises: The Differences and Benefits

Last update: 07 October, 2021

Isotonic and isometric exercises are two types of strength training. They complement each other to add variety and breadth to your workout routines. In fact, incorporating both of them maximizes your benefits in each session.

Both isotonic and isometric exercises offer different ways of working, as well as different advantages. As for which one is better, there isn’t an answer. It depends on what your goals are and what physical situation you’re in.

Let’s take a closer look.

Isotonic exercises

The word isotonic comes from the Greek words iso (meaning “equal”) and tones (meaning “tone”).  The term describes a type of exercise in which your muscles maintain the same tension while performing a movement.

In other words, during isotonic exercises, your muscle contracts and shortens or lengthens against a constant load. Although the length of the muscle changes, the load remains the same during the exercise.

With this in mind, it’s important to differentiate between two types of isotonic contractions: concentric and eccentric.

  • Concentric contraction happens when the muscle contracts and shortens during an exercise against a constant load. For example, any weight lifting involves concentric contractions when lifting or approaching the load.
  • Eccentric contraction happens when the muscle contracts and lengthens during an exercise against a constant load. When lifting weights, the eccentric phase occurs when you go back to the initial position. That is, this happens when you drop or stop using the weight.
A woman exercising with weights.

The advantages of these exercises and some examples

Isotonic exercises offer many benefits and advantages while working out. For example, these are some of the most important ones:

  • Increase blood supply to the muscles.
  • Improve muscular endurance.
  • With fewer repetitions than other strength exercises, you can increase strength and muscle mass.
  • Allow the development of force through the range of motion.
  • Easily exercise all muscle groups using localized or general exercises.
  • Train your whole body for the movements you need to do daily activities.
  • Increase bone density.
  • Maintain your metabolism as you age.
  • Help you lose weight while increasing fat-free mass.

In addition, some popular isotonic exercises are bicep curls, tricep curls, bench press, shoulder press, burpees, and crunches, among many others.

On the other hand, many yoga poses, like the warrior in any of its versions, the tree, the chair, or the dancer are also beneficial and challenging isometric exercises.

Here are some examples of some popular isotonic exercises.

Squats

Squats are a very popular isotonic exercise. You don’t need any equipment to do them. However, you can add weights, bars, or bands to increase the load and intensity.

  • Stand with your legs shoulder-width apart, feet facing forward. If you use weight, put it on your shoulders. If you’re using bands, hold them as if you were holding a bar.
  • Then, without changing the posture of your trunk, that is, without leaning forward, lower your hips, bending your knees. Your hips shouldn’t drop below your knees.
  • Slowly return to your starting position, making a strong contraction in your glutes.

There are different variations for this exercise. For example, you can bring your legs a little closer, placing them shoulder-width apart. Also, you can spread them further and place your feet out. That way, your knees are out when you go down.

Straight leg deadlift

You can do the straight leg deadlift with one bar or two dumbbells. In addition to being very simple, it’s one of the best compound exercises to gain strength and muscle mass.

  • Stand up straight, and hold your weight in front of your thighs.
  • Next, lean forward with your back straight. Go as low as you can without bending your knees.
  • Then, squeeze your glutes to raise your torso and return to your starting position.

Push-ups

Push-ups are another popular type of isotonic exercise. Also, you don’t need any equipment to do them.

  • Lie face down on a mat in a plank position, with your body upright on your feet and your arms stretched out. Have your hands just below your shoulders or a little further apart, depending on your goal for the exercise.
  • Then, slowly lower your chest to the ground, flexing your arms and letting your elbows go out to the sides. Don’t go all the way to the ground.
  • Finally, go back to the starting position by slowly extending your arms.

Isometric exercises

The word isometric comes from the Greek terms iso (meaning “equal”) and metron (meaning “measure”). The term describes a type of exercise where your muscles maintain the same measure, dimension, or length.

In other words, during isometric exercises, the length of the muscle or the angle of the joint doesn’t change during the contraction. That is, the muscles involved during the exercise stay the same length. For example, the plank is probably the most popular isometric exercise.

The advantages of these exercises and some examples

The most prominent benefits and advantages of isometric exercises are the following:

  • Little or no equipment is required.
  • They increase the size of muscles if you do them with weight.
  • You can achieve and maintain maximum muscle contraction.
  • They activate 5% more muscle fibers than isotonic training when using maximum effort.
  • These exercises promote the development of strength in specific muscle groups.
  • They improve bone density and cholesterol levels.
  • They have a positive effect on blood pressure.
  • Strengthen your joints from all angles with these exercises.

Wall squats

Wall squats is a very easy exercise to do. At the same time, they’re also very beneficial. To do them, you just need a sturdy wall.

  • First, stand in front of the wall. Lean back against it so that your back is making full contact with the wall.
  • Lower yourself slowly by taking small steps forward, without separating your back from the wall, until your hips are at the same level as your knees.
  • Stretch your arms out in front, parallel to the ground, to make it easier to maintain your posture and balance.
  • Hold the pose for at least 15-20 seconds.

Forearm plank

Forearm planks are a popular isometric exercise that involves all the core muscles.

  • First, lie on the floor on a mat face down. Have your arms bent and your elbows under your shoulders.
  • Make sure that your feel are shoulder-width apart.
  • Then, raise your hips so that they’re in line with your shoulders, but not above.
  • Squeeze your glutes, abs and pelvic floor, and hold the pose for at least 30 seconds.
A woman doing a plank.

Glute bridges

Glute bridges are another very popular, easy-to-do and highly effective isometric exercise.

  • Lie on the floor, face up, with your legs bent and your heels as close to your glutes as possible.
  • Keep your hands along your trunk.
  • Then, with your knees forward, raise your hips. Make sure that your knees don’t separate and move out. You can use your hands for support, or interlock them under the buttocks.
  • Hold this post for at least 10-15 seconds and lower slowly, rounding out your back.

Isotonic and isometric exercises: Final recommendations

Many experts think that isotonic training offers more benefits than functional training since they use movements that we use in daily life. In addition, they help us both to reduce body fat and increase muscle mass.

However, isometric exercises also contribute to improving daily performance, since they engage your core muscles to stabilize your posture. Also, isometric exercises are great for physical recovery and rehabilitation. They help maintain muscle mass or, at the very least, decrease loss of strength.

Whenever possible, combining isotonic and isometric exercises will help you achieve better results during strength training.

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