Isometric exercises are less popular when it comes to training biceps, but studies show that they are just as effective as more popular isotonic exercises for strengthening muscles. In fact, a study published in the "Journal of Physiology" found that there is no significant difference in strength gains between isotonic and isometric resistance training.
Difference Between Isometric and Isotonic Training
Isometric exercises are those that do not require the muscle to shorten or lengthen throughout the exercise. The muscle remains static, yet it is still working because it is under tension or holding up a weight the entire time. In contrast, isotonic exercises are those that involve the muscle shortening to lift a load and then lengthening under the same load, as in when you lift and lower a weight. The shortening of the muscle is called a concentric contraction and the lengthening is called an eccentric contraction.
Isometric Bicep and Hammer Curls
Isometric curls entail holding on to a weight in a static position. For an isometric bicep curl, you would hold the weight in your hands with both your palms facing up. With hammer curls, you hold the weights with your wrists facing each other. Slowly bend your elbows and curl your arms up until the weight is at your chest level. Hold the weight at this level for at least 30 seconds before lowering it.
Isometric Biceps Hold with Towel
The isometric biceps hold with a towel is easy to perform for beginners because it does not involve carrying heavy weights or the possibility of dropping weights. Twist a large towel and step on to one end with your right foot. Bend your elbow at 90 degrees and grasp on to the other end of the towel where it is in line with your hand. Slightly flex your elbow until you feel resistance and hold this position for 30 seconds before letting go of the towel. Repeat with your other arm.
Drawbacks to Isometric Training
Isometric exercises are not recommended for people with high blood pressure or heart problems because the large increase in muscle tension caused by this exercises can significantly increase blood pressure. Another drawback to isometric exercises is that they strengthen the muscle near or at the joint angle at which you performed the exercise. That means if you are bending your elbow at 45 degrees during your curls, your biceps will be stronger at that angle but not necessarily at 90 degrees.
- The Journal of Physiology: The Effect on Muscle Strength of Maximum Isometric and Isotonic Contractions …; Nancy Salter
- Muscle Physiology: Types of Contractions
- Washington Post: Isometric Biceps Hold with Towel
- MayoClinic.com: Are Isometric Exercises A Good Way to Build Strength
- Journal of Applied Physiology: Myoelectrical and Mechanical Changes Linked to Length Specificity during Isometric Training
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