When crafting your daily workouts, it’s important you understand the differences between various types of exercises. We often categorize exercises is either “isotonic” or “isometric, but what do these terms mean for your training?

Simply put, an isotonic exercise is one where you contract and extend your muscles, such as in a bicep curl, push-up, or squat. Isometric exercises, however, don’t involve any muscle movement. So, isometric refers to “static” exercises, like planks and wall sits.

Up next, we’ll walk you through the basics of isometric and isotonic exercises so you can determine how they might fit into your workout routine.

Isotonic Exercises

An isotonic exercise involves creating equal tension between your muscles throughout the entire movement. Interestingly, “iso-” comes from the Greek meaning “same,” while “-tonic” comes from the Greek tonos, which means “tone” or “tension.”

While the above may sound a bit confusing, the concept itself is relatively simple. In fact, you’ve probably done a lot of isotonic exercises before in your life without even knowing what they were called.

During an isotonic exercise, like a bicep curl, your muscles stay at the same level of tension throughout the rep. In this situation, your biceps and triceps are under tension as you lift a weight from your hip to your shoulder.

What’s unique about isotonic exercises is that they involve two types of muscle movements: concentric and eccentric. In a concentric movement, your muscle shortens. Meanwhile, in an eccentric movement, the muscle lengthens.

So, during a bicep curl, your bicep shortens, and your tricep lengthens as you raise a weight to your shoulders. Throughout the process, both muscles are under a consistent amount of tension until you put the weight on the ground. Hence, a bicep curl is an example of an “isotonic” or “equal tension” exercise.

Advantages And Disadvantages Of Isotonic Exercises

That might all sound fine and dandy, but why would you choose to do isotonic exercises instead of something else? Well, it turns out that isotonic exercises offer a lot of benefits for your overall fitness. Here are some of the advantages and disadvantages of including isotonic exercises in your workout plan:

Pros

  • Increases cardiovascular endurance and health
  • Builds strength that’s functional over a full range of motion
  • Can be done as a bodyweight exercise
  • Improves range of motion
  • Helps maintain a healthy metabolism as you get older
  • Can help protect against injuries
  • Increases overall muscle strength
  • Typically results in increased muscle size
  • Can be used to train nearly every muscle group
  • Increases bone density
  • Helps lower body fat
  • Can help lower blood sugar and cholesterol levels

Cons

  • Can lead to very sore muscles
  • Generally requires a longer rest period between training sessions, especially when using heavy weights
  • Does not evenly strengthen a muscle throughout the entire range of motion, particularly at the beginning and end of each rep

Examples Of Isotonic Exercises

Isotonic exercises are incredibly common. If you’ve ever done a workout routine before, at some point, you’ve almost certainly completed a handful of isotonic exercises. Here are a few examples that you can consider adding to your training sessions:

  • Squats
  • Pull-ups
  • Push-ups
  • Deadlifts
  • Bench press
  • Bicep curls
  • Shoulder shrugs
  • Skull crushers
  • Lat pull-downs

Additionally, most forms of aerobic exercise are also considered to be isotonic. These include:

  • Walking
  • Hiking
  • Running
  • Dancing
  • Swimming
  • Skiing
  • Rock climbing
  • Biking

Isometric Exercises

While isotonic exercises keep an equal tension in your muscles, isometric exercises keep them at an equal length. In an isometric exercise, your body stays in one position, so your muscles are neither lengthening or shortening.

Isometric exercises are often called “static” exercises. When you perform an isometric exercise, you place your muscles under just enough tension that they are bearing a lot of pressure, but not enough to move your body.

If this sounds a bit complicated, worry not. Isometric exercises are simple and effective ways to improve your overall muscle strength and endurance that often require no equipment.

An excellent example of an isometric exercise is a plank. Unlike a pushup, which involves repeatedly flexing and extending your pectorals, deltoids, and triceps, planks keep you in one position. So, in a plank, you’re placing strain on your abdominal muscles and keeping them in a contracted position.

Advantages And Disadvantages Of Isometric Exercises

Isometric exercises are prevalent because of their simplicity. But, every exercise has its advantages and disadvantages. Here are some of the benefits and drawbacks to isometric exercises:

Pros

  • Gentle on your joints, which is suitable for people with arthritis or previous injuries
  • Can help improve muscle tone
  • Requires less time per set when compared to isotonic exercises
  • May improve cholesterol levels
  • Can be used for injury rehabilitation
  • Increases overall bone density
  • May improve digestion
  • Requires minimal equipment
  • Strengthens joints and improves joint flexibility
  • Can help you overcome muscle imbalances
  • Strengthens smaller muscles that often go underdeveloped
  • Some isometric exercises can be done in a seated or prone position, which is ideal for older folks looking to stay in shape

Cons

  • Only allows for strength gains within a specific range of motion
  • Can cause an increase in blood pressure for people who already have hypertension
  • Does not generate a lot of blood flow throughout the muscles, which limits gains in overall muscular endurance
  • Provides limited strength gains when compared to isotonic exercises because of the lack of muscle lengthening

Examples of Isometric Exercises

Isometric exercises are commonly added to workout routines to train smaller muscle groups that are often ignored by isotonic exercises. Here are some isometric exercise examples:

  • Planks
  • Wall sits
  • Glute bridges
  • Overhead hold
  • Static lunges
  • Squat holds
  • Side planks

There are considerably fewer isometric exercises when compared to the overall list of isotonic alternatives because there are only so many positions that you can hold your body in. However, you can always create an isometric exercise by holding a dumbbell, kettlebell, medicine ball, or barbell in a specific position for 20-30 seconds.

Should I Do Isotonic Or Isometric Exercises?

When planning your workouts, it’s important to remember that you don’t have to choose between isotonic and isometric exercises. It’s generally best to incorporate a mix of both into your training regimen.

For the most part, isometric exercises on their own are not enough to build a substantial amount of muscular strength. Additionally, isometric exercises won’t result in a lot of muscular endurance.

Isotonic exercises, however, often neglect our smaller stabilizer muscles, which are essential to increasing our balance and reducing our chances of injury. So, it’s best to include both types of exercises in your daily workouts.

Try to do at least one isometric exercise on each of your training days. For example, if you’re planning your leg day, consider doing a set of wall sits as a warm-up for your squats. Or, you can also introduce planks into your core workouts.

By including the right mix of both isotonic and isometric exercises in your training, you can help ensure that all of your muscles are getting the workout that they need.