Isometric vs. Isotonic Exercises

What is Isometric Exercise?

Isometric Exercise is a fantastic way to exercise the muscles while in a stationary position. Isometric exercise is experienced by pushing or pulling a fixed object like a wall or bar anchored to the floor. Research has shown that a muscle contraction during Isometric exercise produced more force then a contraction generated by lifting weights. Although research shows that Isometric exercise increases muscle tension significantly, it still fails to change the length of the muscles

What is Isotonic Exercise?

Isotonic exactly means equal tension. Isotonic contraction is a contraction in which the tension remains constant as the muscle shortens or lengthens. This can be carried out either with free weights like dumbbells or barbells or with fixed equipments. In both these forms exercises are carried out against a fixed resistance. Although ‘isotonic’ is the term used most frequently to describe fixed resistance variable speed exercise.

Advantages of isometric exercise

  • In isometric exercise one can attain maximum muscular contraction in contrast to Isotonic exercise which are also known as weight training.
  • In isometric exercise one can gain strength but it will only strengthen very isolated areas of the muscle group.
  • Isometric exercise slows muscle erosion and it enhances the tone and shape of muscles.
  • Isometric exercise helps to improve bone density.
  • Long sessions of isometric exercise help to improve digestion and lower cholesterol levels.

Advantages of isotonic exercise

  • Isotonic training is relatively cheap.
  • There are broad ranges of exercises.
  • When you lift weights in Isotonic exercise blood is pumped into the muscles which help in increasing muscular endurance.
  • In isotonic exercises all major muscle groups can be exercised.
  • Isotonic exercise increases the muscle strength in few repetitions.
  • Isotonic exercise lets you to build strength throughout the entire range of motion.

Disadvantages of Isometric exercise

  • Isometric exercise does not generate the same blood flow as isotonic exercises, thereby potentially decreasing the muscular endurance.
  • Building strength during a static contraction in isometric exercise can potentially reduce the speed of the muscle response.
  • Increased blood pressure. It increases blood pressure more than any other form of exercise. This may perhaps lead to a ruptured blood vessel or irregular heartbeat.
  • Isometric exercise allows you to gain strength only within 20 degrees of the angle you hold.

Disadvantages of Isotonic exercise

  • In Isometric exercise there is uneven force throughout each exercise.
  • Exercises may not fully strengthen each muscle group.
  • John Taylor

    “Isotonic training is relatively cheap.” Really? Relative to what? Isometric training requires NO equipment. Bodyweight isotonic can be done largely for free, but with the disadvantage of inability to reach maximum contraction.

    “Isometric exercise does not generate the same blood flow as isotonic exercises, thereby potentially decreasing the muscular endurance.” Increase bloodflow in Isometric exercises using Maxick contractions. Basically, release the tension slightly (and periodically) before resuming the maximum contraction.

    “Isometric exercise allows you to gain strength only within 20 degrees of the angle you hold”. You are referring to angular specificity. This has been studied, and no proof of the advantage of “full range of motion” has EVER been found. This may be due largely to the difficulty in measuring the effect, even with specially adapted machines.

    “Increased blood pressure”. Of course, you are achieving maximal contraction, so don’t hold your breath. This is one reason why paramedics are on standby during bodybuilding competitions, as contestants pose with isometric contractions.

    “Building strength during a static contraction in isometric exercise can potentially reduce the speed of the muscle response.” Reference please, I wish to study this.

    Read John Peterson’s book, obtainable HERE.

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