Isometric exercise is an exercising technique designed to build maximum strength. Isometric exercises are also used to rehabilitate injuries when joint range of motion is limited. An isometric exercise is one in which your joint and muscles remain still during the contraction. An example of an isometric exercise is holding two dumbbells out to the side parallel to the floor for up to 60 seconds. There are two main types of isometric exercises: maximal and submaximal. Both types help to maximize the number of muscle fibers recruited during a lift, which helps build more lean muscle and power.
The Difference Between Maximal and Submaximal
Maximal isometric exercise involves pushing or pulling something at maximum force, such as pushing against an immovable wall or pulling as hard as you can on a rope attached securely to a fixed point. Submaximal isometric exercise, on the other hand, doesn’t involve maximum force on your part. Instead, it involves holding a static movement steady without flexing the joint or joints connected to the muscles being exercised. Examples of submaximal isometric exercises include holding a dumbbell out to the side and doing wall sits.
For Maximum Power
For maximum power, go with maximal isometric exercises. The obvious reason is because maximal power helps generate a greater effect on your muscle fibers fighting to complete whatever action you’re doing. Maximal isometric exercise causes your muscles to recruit a greater number of muscle fibers during the action compared to submaximal movements. This makes maximal movements a better choice for athletes and fitness buffs looking to build power and muscle size.
Get the Most From Isometrics
Focus your isometric training on the part of your body in which you wish to build power. For example, build core power using the plank position or build power in your quadriceps using wall sits. A technique referred to as explosive isometrics may help maximize muscle and strength gains. It’s a way to build quick, explosive power in your muscles by doing fast maximal isometric repetitions. This is particularly beneficial for athletes. An example is a football player exploding from a three-point stance and pushing against a padded wall or immovable tackle dummy. A second example is a baseball pitcher mimicking a throwing motion while holding a resistance band affixed securely behind him.
The biggest downside of isometric exercise is its limitations when it comes to dynamic power. Isometric training only builds muscle power at the angle you’re generating the force. For example, holding a dumbbell during a biceps curl movement at a steady 45-degree angle for 10 or more seconds will only build strength and power at that arm angle. It doesn’t build equal power throughout the entire biceps-curl movement. You’d have to do sets of holding the weight at dozens of different angles to encompass the entire range of motion.
Despite the dynamic training limitations of isometric training, its ability to build substantial muscle power is undeniable. Holding an isometric pose for just six seconds recruits 5 percent more muscle fibers compared to traditional dynamic training, and holding it longer may recruit all of the muscle fibers in the muscles you’re exercising. A landmark study conducted by J. Duchateau and K. Hainaut in 1984 compared dynamic versus isometric exercise training found that after three months, participants doing the isometric exercise showed a 51-percent gain in muscle power compared to just 19 percent in the dynamic training group. Isometrics may help you build substantial muscle power, but a combination of dynamic and isometric training is the most efficient way to develop power, strength and muscle size at all joint angles.
- Sports Fitness Advisor: Isometric Exercises & Static Strength Training
- Elitefts: Explosive Isometrics: Speed Training With the Brakes On
- SB Coaches College: Functional Isometric Training for Sport
- Journal of Applied Physiology: Isometric or Dynamic Training -- Differential Effects on Mechanical Properties of a Human Muscle
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